From: hgn <hgodden00@gmail.com>
Date: Sun, 15 Jan 2023 19:48:24 +0000 (+0000)
Subject: a fairly major physics update
X-Git-Url: https://harrygodden.com/git/?a=commitdiff_plain;h=2a238d32da833812e837cf38e16a7685c98db5c3;p=carveJwlIkooP6JGAAIwe30JlM.git

a fairly major physics update
---

diff --git a/blender_export.py b/blender_export.py
index 8cd60ea..515acd7 100644
--- a/blender_export.py
+++ b/blender_export.py
@@ -548,13 +548,14 @@ class classtype_skeleton(Structure):
 class classtype_bone(Structure):
 #{
    _pack_ = 1
-   _fields_ = [("deform",c_uint32),
+   _fields_ = [("flags",c_uint32),
                ("ik_target",c_uint32),
                ("ik_pole",c_uint32),
-               ("collider",c_uint32),
-               ("use_limits",c_uint32),
-               ("angle_limits",(c_float*3)*2),
-               ("hitbox",(c_float*3)*2)]
+               ("hitbox",(c_float*3)*2),
+               ("conevx",c_float*3),
+               ("conevy",c_float*3),
+               ("coneva",c_float*3),
+               ("conet",c_float)]
 
    def encode_obj(_, node,node_def):
    #{
@@ -563,19 +564,24 @@ class classtype_bone(Structure):
       armature_def = node_def['linked_armature']
       obj = node_def['bone']
       
-      _.deform = node_def['deform']
+      _.flags = node_def['deform']
       
       if 'ik_target' in node_def:
       #{
+         _.flags |= 0x2
          _.ik_target = armature_def['bones'].index( node_def['ik_target'] )
          _.ik_pole   = armature_def['bones'].index( node_def['ik_pole'] )
       #}
       
       # For ragdolls
       #
-      if obj.cv_data.collider:
+      if obj.cv_data.collider != 'collider_none':
       #{
-         _.collider = 1
+         if obj.cv_data.collider == 'collider_box':
+            _.flags |= 0x4
+         else:
+            _.flags |= 0x8
+
          _.hitbox[0][0] =  obj.cv_data.v0[0]
          _.hitbox[0][1] =  obj.cv_data.v0[2]
          _.hitbox[0][2] = -obj.cv_data.v1[1]
@@ -586,13 +592,17 @@ class classtype_bone(Structure):
 
       if obj.cv_data.con0:
       #{
-         _.use_limits = 1 
-         _.angle_limits[0][0] =  obj.cv_data.mins[0]
-         _.angle_limits[0][1] =  obj.cv_data.mins[2]
-         _.angle_limits[0][2] = -obj.cv_data.maxs[1]
-         _.angle_limits[1][0] =  obj.cv_data.maxs[0]
-         _.angle_limits[1][1] =  obj.cv_data.maxs[2]
-         _.angle_limits[1][2] = -obj.cv_data.mins[1]
+         _.flags |= 0x100
+         _.conevx[0] =  obj.cv_data.conevx[0]
+         _.conevx[1] =  obj.cv_data.conevx[2]
+         _.conevx[2] = -obj.cv_data.conevx[1]
+         _.conevy[0] =  obj.cv_data.conevy[0]
+         _.conevy[1] =  obj.cv_data.conevy[2]
+         _.conevy[2] = -obj.cv_data.conevy[1]
+         _.coneva[0] =  obj.cv_data.coneva[0]
+         _.coneva[1] =  obj.cv_data.coneva[2]
+         _.coneva[2] = -obj.cv_data.coneva[1]
+         _.conet = obj.cv_data.conet
       #}
    #}
 #}
@@ -1279,7 +1289,7 @@ def encoder_build_scene_graph( collection ):
                   #}
                #}
 
-               if n.cv_data.collider:
+               if n.cv_data.collider != 'collider_none':
                   tree['collider_count'] += 1
 
                btree['deform'] = n.use_deform
@@ -2041,6 +2051,44 @@ def cv_draw_sphere( pos, radius, colour ):
    cv_draw_lines()
 #}
 
+# Draw axis alligned sphere at position with radius
+#
+def cv_draw_halfsphere( pos, tx, ty, tz, radius, colour ):
+#{
+   global cv_view_verts, cv_view_colours
+   
+   ly = pos + tz*radius
+   lx = pos + ty*radius
+   lz = pos + tz*radius
+   
+   pi = 3.14159265358979323846264
+
+   for i in range(16):
+   #{
+      t = ((i+1.0) * 1.0/16.0) * pi
+      s = math.sin(t)
+      c = math.cos(t)
+
+      s1 = math.sin(t*2.0)
+      c1 = math.cos(t*2.0)
+
+      py = pos + s*tx*radius +                c *tz*radius
+      px = pos + s*tx*radius + c *ty*radius 
+      pz = pos +               s1*ty*radius + c1*tz*radius
+
+      cv_view_verts += [ px, lx ]
+      cv_view_verts += [ py, ly ]
+      cv_view_verts += [ pz, lz ]
+
+      cv_view_colours += [ colour, colour, colour, colour, colour, colour ]
+
+      ly = py
+      lx = px
+      lz = pz
+   #}
+   cv_draw_lines()
+#}
+
 # Draw transformed -1 -> 1 cube
 #
 def cv_draw_ucube( transform, colour ):
@@ -2096,9 +2144,9 @@ def cv_draw_line2( p0, p1, c0, c1 ):
    cv_draw_lines()
 #}
 
-# Just the tx because we dont really need ty for this app
+# 
 #
-def cv_tangent_basis_tx( n, tx ):
+def cv_tangent_basis( n, tx, ty ):
 #{
    if abs( n[0] ) >= 0.57735027:
    #{
@@ -2114,6 +2162,11 @@ def cv_tangent_basis_tx( n, tx ):
    #}
 
    tx.normalize()
+   _ty = n.cross( tx )
+
+   ty[0] = _ty[0]
+   ty[1] = _ty[1]
+   ty[2] = _ty[2]
 #}
 
 # Draw coloured arrow
@@ -2127,7 +2180,8 @@ def cv_draw_arrow( p0, p1, c0 ):
    n.normalize()
 
    tx = Vector((1,0,0))
-   cv_tangent_basis_tx( n, tx )
+   ty = Vector((1,0,0))
+   cv_tangent_basis( n, tx, ty )
    
    cv_view_verts += [p0,p1, midpt+(tx-n)*0.15,midpt, midpt+(-tx-n)*0.15,midpt ]
    cv_view_colours += [c0,c0,c0,c0,c0,c0]
@@ -2260,19 +2314,61 @@ def draw_limit( obj, center, major, minor, amin, amax, colour ):
    cv_draw_lines()
 #}
 
+# Cone and twist limit
+#
+def draw_cone_twist( center, vx, vy, va ):
+#{
+   global cv_view_verts, cv_view_colours
+   axis = vy.cross( vx )
+   axis.normalize()
+
+   size = 0.12
+
+   cv_view_verts += [center, center+va*size]
+   cv_view_colours += [ (1,1,1,1), (1,1,1,1) ]
+
+   for x in range(32):
+   #{
+      t0 = (x/32) * math.tau
+      t1 = ((x+1)/32) * math.tau
+
+      c0 = math.cos(t0)
+      s0 = math.sin(t0)
+      c1 = math.cos(t1)
+      s1 = math.sin(t1)
+      
+      p0 = center + (axis + vx*c0 + vy*s0).normalized() * size
+      p1 = center + (axis + vx*c1 + vy*s1).normalized() * size
+
+      col0 = ( abs(c0), abs(s0), 0.0, 1.0 )
+      col1 = ( abs(c1), abs(s1), 0.0, 1.0 )
+
+      cv_view_verts += [center, p0, p0, p1]
+      cv_view_colours += [ (0,0,0,0), col0, col0, col1 ]
+   #}
+
+   cv_draw_lines()
+#}
+
 # Draws constraints and stuff for the skeleton. This isnt documented and wont be
 #
 def draw_skeleton_helpers( obj ):
 #{
    global cv_view_verts, cv_view_colours
 
+   if obj.data.pose_position != 'REST':
+   #{
+      return
+   #}
+
    for bone in obj.data.bones:
    #{
-      if bone.cv_data.collider and (obj.data.pose_position == 'REST'):
+      c = bone.head_local
+      a = Vector((bone.cv_data.v0[0], bone.cv_data.v0[1], bone.cv_data.v0[2]))
+      b = Vector((bone.cv_data.v1[0], bone.cv_data.v1[1], bone.cv_data.v1[2]))
+
+      if bone.cv_data.collider == 'collider_box':
       #{
-         c = bone.head_local
-         a = bone.cv_data.v0
-         b = bone.cv_data.v1
          
          vs = [None]*8
          vs[0]=obj.matrix_world@Vector((c[0]+a[0],c[1]+a[1],c[2]+a[2]))
@@ -2296,20 +2392,67 @@ def draw_skeleton_helpers( obj ):
             cv_view_verts += [(v1[0],v1[1],v1[2])]
             cv_view_colours += [(0.5,0.5,0.5,0.5),(0.5,0.5,0.5,0.5)]
          #}
+      #}
+      elif bone.cv_data.collider == 'collider_capsule':
+      #{
+         v0 = b-a
+         major_axis = 0
+         largest = -1.0
 
-         center = obj.matrix_world @ c
-         if bone.cv_data.con0:
+         for i in range(3):
          #{
-            draw_limit( obj, c, Vector((0,1,0)),Vector((0,0,1)), \
-                        bone.cv_data.mins[0], bone.cv_data.maxs[0], \
-                        (1,0,0,1))
-            draw_limit( obj, c, Vector((0,0,1)),Vector((1,0,0)), \
-                        bone.cv_data.mins[1], bone.cv_data.maxs[1], \
-                        (0,1,0,1))
-            draw_limit( obj, c, Vector((1,0,0)),Vector((0,1,0)), \
-                        bone.cv_data.mins[2], bone.cv_data.maxs[2], \
-                        (0,0,1,1))
+            if abs(v0[i]) > largest:
+            #{
+               largest = abs(v0[i])
+               major_axis = i
+            #}
          #}
+
+         v1 = Vector((0,0,0))
+         v1[major_axis] = 1.0
+
+         tx = Vector((0,0,0))
+         ty = Vector((0,0,0))
+
+         cv_tangent_basis( v1, tx, ty )
+         r = (abs(tx.dot( v0 )) + abs(ty.dot( v0 ))) * 0.25
+         l = v0[ major_axis ] - r*2
+
+         p0 = obj.matrix_world@Vector( c + (a+b)*0.5 + v1*l*-0.5 )
+         p1 = obj.matrix_world@Vector( c + (a+b)*0.5 + v1*l* 0.5 )
+
+         colour = [0.2,0.2,0.2,1.0]
+         colour[major_axis] = 0.5
+
+         cv_draw_halfsphere( p0, -v1, ty, tx, r, colour )
+         cv_draw_halfsphere( p1,  v1, ty, tx, r, colour )
+         cv_draw_line( p0+tx* r, p1+tx* r, colour )
+         cv_draw_line( p0+tx*-r, p1+tx*-r, colour )
+         cv_draw_line( p0+ty* r, p1+ty* r, colour )
+         cv_draw_line( p0+ty*-r, p1+ty*-r, colour )
+      #}
+      else:
+      #{
+         continue
+      #}
+
+      center = obj.matrix_world @ c
+      if bone.cv_data.con0:
+      #{
+         vx = Vector([bone.cv_data.conevx[_] for _ in range(3)])
+         vy = Vector([bone.cv_data.conevy[_] for _ in range(3)])
+         va = Vector([bone.cv_data.coneva[_] for _ in range(3)])
+         draw_cone_twist( center, vx, vy, va )
+
+         #draw_limit( obj, c, Vector((0,0,1)),Vector((0,-1,0)), \
+         #            bone.cv_data.mins[0], bone.cv_data.maxs[0], \
+         #            (1,0,0,1))
+         #draw_limit( obj, c, Vector((0,-1,0)),Vector((1,0,0)), \
+         #            bone.cv_data.mins[1], bone.cv_data.maxs[1], \
+         #            (0,1,0,1))
+         #draw_limit( obj, c, Vector((1,0,0)),Vector((0,0,1)), \
+         #            bone.cv_data.mins[2], bone.cv_data.maxs[2], \
+         #            (0,0,1,1))
       #}
    #}
 #}
@@ -2428,13 +2571,25 @@ class CV_OBJ_SETTINGS(bpy.types.PropertyGroup):
 
 class CV_BONE_SETTINGS(bpy.types.PropertyGroup):
 #{
-   collider: bpy.props.BoolProperty(name="Collider",default=False)
+   collider: bpy.props.EnumProperty(
+      name="Collider Type", 
+      items = [
+      ('collider_none', "collider_none", "", 0),
+      ('collider_box', "collider_box", "", 1),
+      ('collider_capsule', "collider_capsule", "", 2),
+      ])
+
    v0: bpy.props.FloatVectorProperty(name="v0",size=3)
    v1: bpy.props.FloatVectorProperty(name="v1",size=3)
 
    con0: bpy.props.BoolProperty(name="Constriant 0",default=False)
    mins: bpy.props.FloatVectorProperty(name="mins",size=3)
    maxs: bpy.props.FloatVectorProperty(name="maxs",size=3)
+
+   conevx: bpy.props.FloatVectorProperty(name="conevx",size=3)
+   conevy: bpy.props.FloatVectorProperty(name="conevy",size=3)
+   coneva: bpy.props.FloatVectorProperty(name="coneva",size=3)
+   conet:  bpy.props.FloatProperty(name="conet")
 #}
 
 class CV_BONE_PANEL(bpy.types.Panel):
@@ -2459,8 +2614,11 @@ class CV_BONE_PANEL(bpy.types.Panel):
 
       _.layout.label( text="Angle Limits" )
       _.layout.prop( bone.cv_data, "con0" )
-      _.layout.prop( bone.cv_data, "mins" )
-      _.layout.prop( bone.cv_data, "maxs" )
+
+      _.layout.prop( bone.cv_data, "conevx" )
+      _.layout.prop( bone.cv_data, "conevy" )
+      _.layout.prop( bone.cv_data, "coneva" )
+      _.layout.prop( bone.cv_data, "conet" )
    #}
 #}
 
diff --git a/bvh.h b/bvh.h
index 41a4108..e79e3dd 100644
--- a/bvh.h
+++ b/bvh.h
@@ -5,7 +5,6 @@
 #ifndef BVH_H
 #define BVH_H
 #include "common.h"
-#include "distq.h"
 
 /*
  * Usage:
@@ -178,7 +177,28 @@ VG_STATIC bh_tree *bh_create( void *lin_alloc, bh_system *system,
    return bh;
 }
 
-VG_STATIC void bh_debug_node( bh_tree *bh, u32 inode, v3f pos, u32 colour )
+/*
+ * Draw items in this leaf node.
+ * *item_debug() must be set!
+ */
+VG_STATIC void bh_debug_leaf( bh_tree *bh, bh_node *node )
+{
+   vg_line_boxf( node->bbx, 0xff00ff00 );
+
+   if( bh->system->item_debug )
+   {
+      for( u32 i=0; i<node->count; i++ )
+      {
+         u32 idx = node->start+i;
+         bh->system->item_debug( bh->user, idx );
+      }
+   }
+}
+
+/*
+ * Trace the bh tree all the way down to the leaf nodes where pos is inside
+ */
+VG_STATIC void bh_debug_trace( bh_tree *bh, u32 inode, v3f pos, u32 colour )
 {
    bh_node *node = &bh->nodes[ inode ];
 
@@ -189,21 +209,13 @@ VG_STATIC void bh_debug_node( bh_tree *bh, u32 inode, v3f pos, u32 colour )
       {
          vg_line_boxf( node->bbx, colour );
 
-         bh_debug_node( bh, node->il, pos, colour );
-         bh_debug_node( bh, node->ir, pos, colour );
+         bh_debug_trace( bh, node->il, pos, colour );
+         bh_debug_trace( bh, node->ir, pos, colour );
       }
       else
       {
-         vg_line_boxf( node->bbx, 0xff00ff00 );
-
          if( bh->system->item_debug )
-         {
-            for( u32 i=0; i<node->count; i++ )
-            {
-               u32 idx = node->start+i;
-               bh->system->item_debug( bh->user, idx );
-            }
-         }
+            bh_debug_leaf( bh, node );
       }
    }
 }
@@ -288,39 +300,39 @@ VG_STATIC int bh_next( bh_tree *bh, bh_iter *it, boxf box, int *em )
    {
       bh_node *inode = &bh->nodes[ it->stack[it->depth].id ];
       
-      if( box_overlap( inode->bbx, box ) )
+      /* Only process overlapping nodes */
+      if( !box_overlap( inode->bbx, box ) )
       {
-         if( inode->count )
+         it->depth --;
+         continue;
+      }
+
+      if( inode->count )
+      {
+         if( it->i < inode->count )
          {
-            if( it->i < inode->count )
-            {
-               *em = inode->start+it->i;
-               it->i ++;
-               return 1;
-            }
-            else
-            {
-               it->depth --;
-               it->i = 0;
-            }
+            *em = inode->start+it->i;
+            it->i ++;
+            return 1;
          }
          else
          {
-            if( it->depth+1 >= vg_list_size(it->stack) )
-            {
-               vg_error( "Maximum stack reached!\n" );
-               return 0;
-            }
-
-            it->stack[it->depth  ].id = inode->il;
-            it->stack[it->depth+1].id = inode->ir;
-            it->depth ++;
+            it->depth --;
             it->i = 0;
          }
       }
       else
       {
-         it->depth --;
+         if( it->depth+1 >= vg_list_size(it->stack) )
+         {
+            vg_error( "Maximum stack reached!\n" );
+            return 0;
+         }
+
+         it->stack[it->depth  ].id = inode->il;
+         it->stack[it->depth+1].id = inode->ir;
+         it->depth ++;
+         it->i = 0;
       }
    }
 
diff --git a/distq.h b/distq.h
deleted file mode 100644
index 1ae5436..0000000
--- a/distq.h
+++ /dev/null
@@ -1,7 +0,0 @@
-#ifndef DISTQ_H
-#define DISTQ_H
-
-#include "vg_m.h"
-
-
-#endif /* DISTQ_H */
diff --git a/maps_src/mp_gridmap.mdl b/maps_src/mp_gridmap.mdl
index 78b0dd0..1f1079f 100644
Binary files a/maps_src/mp_gridmap.mdl and b/maps_src/mp_gridmap.mdl differ
diff --git a/model.h b/model.h
index be0666a..287eefd 100644
--- a/model.h
+++ b/model.h
@@ -68,6 +68,26 @@ enum material_flag
    k_material_flag_grind_surface    = 0x8
 };
 
+enum bone_flag
+{
+   k_bone_flag_deform               = 0x1,
+   k_bone_flag_ik                   = 0x2,
+   k_bone_flag_collider_box         = 0x4,
+   k_bone_flag_collider_capsule     = 0x8,
+   k_bone_flag_collider_reserved0   = 0x10,
+   k_bone_flag_collider_reserved1   = 0x20,
+   k_bone_flag_collider_reserved2   = 0x40,
+   k_bone_flag_collider_reserved3   = 0x80,
+   k_bone_flag_collider_any         = k_bone_flag_collider_box |
+                                      k_bone_flag_collider_capsule |
+                                      k_bone_flag_collider_reserved0 |
+                                      k_bone_flag_collider_reserved1 |
+                                      k_bone_flag_collider_reserved2 |
+                                      k_bone_flag_collider_reserved3,
+   k_bone_flag_cone_constraint      = 0x100,
+   k_bone_flag_force_u32            = 0xffffffff
+};
+
 #pragma pack(push,1)
 
 struct mdl_vert
@@ -200,14 +220,14 @@ struct classtype_route
 
 struct classtype_bone
 {
-   u32 deform,
+   u32 flags,
        ik_target,
-       ik_pole,
-       collider,
-       use_limits;
+       ik_pole;
 
-   v3f angle_limits[2];
    boxf hitbox;
+
+   v3f conevx, conevy, coneva;
+   float conet;
 };
 
 struct classtype_skeleton
diff --git a/models_src/ch_jordan.mdl b/models_src/ch_jordan.mdl
index 7130ad0..0d147d1 100644
Binary files a/models_src/ch_jordan.mdl and b/models_src/ch_jordan.mdl differ
diff --git a/models_src/ch_new.mdl b/models_src/ch_new.mdl
index c11c27f..53b5900 100644
Binary files a/models_src/ch_new.mdl and b/models_src/ch_new.mdl differ
diff --git a/models_src/ch_outlaw.mdl b/models_src/ch_outlaw.mdl
index f3d7858..29609e7 100644
Binary files a/models_src/ch_outlaw.mdl and b/models_src/ch_outlaw.mdl differ
diff --git a/player.h b/player.h
index 2325f72..0e92f3a 100644
--- a/player.h
+++ b/player.h
@@ -194,17 +194,28 @@ VG_STATIC struct gplayer
       struct ragdoll_part
       {
          u32 bone_id;
-         v3f offset;
+         //v3f offset;
+         
+         /* Collider transform relative to bone */
+         m4x3f collider_mtx,
+               inv_collider_mtx;
 
          u32 use_limits;
          v3f limits[2];
 
          rigidbody  rb;
          u32 parent;
+         u32 colour;
       }
       ragdoll[32];
       u32 ragdoll_count;
 
+      rb_constr_pos  position_constraints[32];
+      u32            position_constraints_count;
+
+      rb_constr_swingtwist cone_constraints[32];
+      u32                  cone_constraints_count;
+
       int shoes[2];
    }
    mdl;
@@ -241,6 +252,8 @@ VG_STATIC void player_mouseview(void);
  *                                    Events
  * -----------------------------------------------------------------------------
  */
+VG_STATIC int kill_player( int argc, char const *argv[] );
+VG_STATIC int reset_player( int argc, char const *argv[] );
 
 VG_STATIC void player_init(void)                                         /* 1 */
 {
@@ -364,11 +377,51 @@ VG_STATIC void player_init(void)                                         /* 1 */
       .persistent = 1
    });
 
+   vg_convar_push( (struct vg_convar){
+      .name = "k_ragdoll_limit_scale",
+      .data = &k_ragdoll_limit_scale,
+      .data_type = k_convar_dtype_f32,
+      .opt_f32 = { .clamp = 0 },
+      .persistent = 1
+   });
+
+   vg_convar_push( (struct vg_convar){
+      .name = "k_ragdoll_div",
+      .data = &k_ragdoll_div,
+      .data_type = k_convar_dtype_i32,
+      .opt_i32 = { .clamp=0 },
+      .persistent = 1
+   });
+
+   vg_convar_push( (struct vg_convar){
+      .name = "k_ragdoll_debug_collider",
+      .data = &k_ragdoll_debug_collider,
+      .data_type = k_convar_dtype_i32,
+      .opt_i32 = { .clamp=0 },
+      .persistent = 1
+   });
+
+   vg_convar_push( (struct vg_convar){
+      .name = "k_ragdoll_debug_constraints",
+      .data = &k_ragdoll_debug_constraints,
+      .data_type = k_convar_dtype_i32,
+      .opt_i32 = { .clamp=0 },
+      .persistent = 1
+   });
+
 	vg_function_push( (struct vg_cmd){
 		.name = "reset",
 		.function = reset_player
 	});
 
+	vg_function_push( (struct vg_cmd){
+		.name = "kill",
+		.function = kill_player
+	});
+
+   /* HACK */
+   rb_register_cvar();
+
    player.rewind_length = 0;
    player.rewind_buffer = 
       vg_linear_alloc( vg_mem.rtmemory, 
diff --git a/player_animation.h b/player_animation.h
index 98aa256..08a5405 100644
--- a/player_animation.h
+++ b/player_animation.h
@@ -30,7 +30,6 @@ VG_STATIC void player_animate_offboard(void)
    mdl_keyframe apose[32], bpose[32];
    struct skeleton *sk = &player.mdl.sk;
 
-
    if( player.walk > 0.025f )
    {
       /* TODO move */
@@ -88,6 +87,8 @@ VG_STATIC void player_animate(void)
 {
    struct player_phys *phys = &player.phys;
    rb_extrapolate_transform( &player.phys.rb, player.visual_transform );
+   v3_muladds( player.visual_transform[3], phys->rb.up, -0.2f, 
+               player.visual_transform[3] );
 
    v4f qfake_rot;
    m3x3f fake_rot;
diff --git a/player_physics.h b/player_physics.h
index a2aabff..6a744e8 100644
--- a/player_physics.h
+++ b/player_physics.h
@@ -1366,6 +1366,12 @@ VG_STATIC void player_freecam(void)
    v3_add( move_vel, player.camera_pos, player.camera_pos );
 }
 
+VG_STATIC int kill_player( int argc, char const *argv[] )
+{
+   player_kill();
+   return 0;
+}
+
 VG_STATIC int reset_player( int argc, char const *argv[] )
 {
    struct player_phys *phys = &player.phys;
@@ -1428,10 +1434,12 @@ VG_STATIC int reset_player( int argc, char const *argv[] )
 
    v3f delta = {1.0f,0.0f,0.0f};
    m3x3_mulv( the_long_way, delta, delta );
-
-   player.angles[0] = atan2f( delta[0], -delta[2] ); 
-   player.angles[1] = -asinf( delta[1] );
-
+   
+   if( !freecam )
+   {
+      player.angles[0] = atan2f( delta[0], -delta[2] ); 
+      player.angles[1] = -asinf( delta[1] );
+   }
 
    v4_copy( rp->q, phys->rb.q );
    v3_copy( rp->co, phys->rb.co );
diff --git a/player_ragdoll.h b/player_ragdoll.h
index 6193bf7..0e48f0c 100644
--- a/player_ragdoll.h
+++ b/player_ragdoll.h
@@ -4,7 +4,94 @@
 #include "player.h"
 
 VG_STATIC float k_ragdoll_floatyiness = 20.0f,
-             k_ragdoll_floatydrag  = 1.0f;
+                k_ragdoll_floatydrag  = 1.0f,
+                k_ragdoll_limit_scale = 1.0f;
+
+VG_STATIC int   k_ragdoll_div = 1,
+                ragdoll_frame = 0,
+                k_ragdoll_debug_collider = 1,
+                k_ragdoll_debug_constraints = 0;
+
+VG_STATIC void player_init_ragdoll_bone_collider( struct skeleton_bone *bone,
+                                                  struct ragdoll_part *rp )
+{
+   m4x3_identity( rp->collider_mtx );
+
+   if( bone->flags & k_bone_flag_collider_box )
+   {
+      v3f delta;
+      v3_sub( bone->hitbox[1], bone->hitbox[0], delta );
+      v3_muls( delta, 0.5f, delta );
+      v3_add( bone->hitbox[0], delta, rp->collider_mtx[3] );
+
+      v3_copy( delta, rp->rb.bbx[1] );
+      v3_muls( delta, -1.0f, rp->rb.bbx[0] );
+
+      q_identity( rp->rb.q );
+      rp->rb.type = k_rb_shape_box;
+      rp->colour = 0xffcccccc;
+   }
+   else if( bone->flags & k_bone_flag_collider_capsule )
+   {
+      v3f v0, v1, tx, ty;
+      v3_sub( bone->hitbox[1], bone->hitbox[0], v0 );
+
+      int major_axis = 0;
+      float largest = -1.0f;
+
+      for( int i=0; i<3; i ++ )
+      {
+         if( fabsf( v0[i] ) > largest )
+         {
+            largest = fabsf( v0[i] );
+            major_axis = i;
+         }
+      }
+      
+      v3_zero( v1 );
+      v1[ major_axis ] = 1.0f;
+      rb_tangent_basis( v1, tx, ty );
+      
+      float r = (fabsf(v3_dot(tx,v0)) + fabsf(v3_dot(ty,v0))) * 0.25f,
+            l = fabsf(v0[ major_axis ]);
+      
+      /* orientation */
+      v3_muls( tx, -1.0f, rp->collider_mtx[0] );
+      v3_muls( v1, -1.0f, rp->collider_mtx[1] );
+      v3_muls( ty, -1.0f, rp->collider_mtx[2] );
+      v3_add( bone->hitbox[0], bone->hitbox[1], rp->collider_mtx[3] );
+      v3_muls( rp->collider_mtx[3], 0.5f, rp->collider_mtx[3] );
+
+      rp->rb.type = k_rb_shape_capsule;
+      rp->rb.inf.capsule.height = l;
+      rp->rb.inf.capsule.radius = r;
+
+      rp->colour = 0xff000000 | (0xff << (major_axis*8));
+   }
+   else
+      vg_fatal_exit_loop( "Invalid bone collider type" );
+
+   m4x3_invert_affine( rp->collider_mtx, rp->inv_collider_mtx );
+
+   /* Position collider into rest */
+   m3x3_q( rp->collider_mtx, rp->rb.q );
+   v3_add( rp->collider_mtx[3], bone->co, rp->rb.co );
+   rp->rb.is_world = 0;
+   rb_init( &rp->rb );
+}
+
+/*
+ * Get parent index in the ragdoll
+ */
+VG_STATIC u32 ragdoll_bone_parent( struct player_model *mdl, u32 bone_id )
+{
+   for( u32 j=0; j<mdl->ragdoll_count; j++ )
+      if( mdl->ragdoll[ j ].bone_id == bone_id )
+         return j;
+
+   vg_fatal_exit_loop( "Referenced parent bone does not have a rigidbody" );
+   return 0;
+}
 
 /*
  * Setup ragdoll colliders 
@@ -21,54 +108,82 @@ VG_STATIC void player_init_ragdoll(void)
    }
 
    mdl->ragdoll_count = 0;
+   mdl->position_constraints_count = 0;
+   mdl->cone_constraints_count = 0;
 
    for( u32 i=0; i<mdl->sk.bone_count; i ++ )
    {
       struct skeleton_bone *bone = &mdl->sk.bones[i];
-      
-      if( bone->collider )
-      {
-         if( mdl->ragdoll_count > vg_list_size(player.mdl.ragdoll) )
-            vg_fatal_exit_loop( "Playermodel has too many colliders" );
 
-         struct ragdoll_part *rp = &mdl->ragdoll[ mdl->ragdoll_count ++ ];
-         rp->bone_id = i;
-         
-         v3f delta;
-         v3_sub( bone->hitbox[1], bone->hitbox[0], delta );
-         v3_muls( delta, 0.5f, delta );
+      /*
+       * Bones with colliders
+       */
+      if( !(bone->flags & k_bone_flag_collider_any) )
+         continue;
 
-         v3_add( bone->hitbox[0], delta, rp->offset );
+      if( mdl->ragdoll_count > vg_list_size(player.mdl.ragdoll) )
+         vg_fatal_exit_loop( "Playermodel has too many colliders" );
 
-         v3_copy( delta, rp->rb.bbx[1] );
-         v3_muls( delta, -1.0f, rp->rb.bbx[0] );
+      struct ragdoll_part *rp = &mdl->ragdoll[ mdl->ragdoll_count ++ ];
+      rp->bone_id = i;
+      rp->parent = 0xffffffff;
 
-         q_identity( rp->rb.q );
-         v3_add( bone->co, rp->offset, rp->rb.co );
-         rp->rb.type = k_rb_shape_box;
-         rp->rb.is_world = 0;
-         rp->parent = 0xffffffff;
+      player_init_ragdoll_bone_collider( bone, rp );
+      
+      struct mdl_node *pnode = mdl_node_from_id( src, bone->orig_node );
+      struct classtype_bone *inf = mdl_get_entdata( src, pnode );
+      
+      /*
+       * Bones with collider and parent
+       */
+      if( !bone->parent )
+         continue;
 
-         if( bone->parent )
-         {
-            for( u32 j=0; j<mdl->ragdoll_count; j++ )
-            {
-               if( mdl->ragdoll[ j ].bone_id == bone->parent )
-               {
-                  rp->parent = j;
-                  break;
-               }
-            }
-         }
+      rp->parent = ragdoll_bone_parent( mdl, bone->parent );
+      
+      /* Always assign a point-to-point constraint */
+      struct rb_constr_pos *c = 
+         &mdl->position_constraints[ mdl->position_constraints_count ++ ];
+
+      struct skeleton_bone *bj = &mdl->sk.bones[rp->bone_id];
+      struct ragdoll_part  *pp = &mdl->ragdoll[rp->parent];
+      struct skeleton_bone *bp = &mdl->sk.bones[pp->bone_id];
+
+      /* Convention: rba -- parent, rbb -- child */
+      c->rba = &pp->rb;
+      c->rbb = &rp->rb;
+
+      v3f delta;
+      v3_sub( bj->co, bp->co, delta );
+      m4x3_mulv( rp->inv_collider_mtx, (v3f){0.0f,0.0f,0.0f}, c->lcb );
+      m4x3_mulv( pp->inv_collider_mtx, delta, c->lca );
+      
+      if( inf->flags & k_bone_flag_cone_constraint )
+      {
+         struct rb_constr_swingtwist *a = 
+            &mdl->cone_constraints[ mdl->cone_constraints_count ++ ];
+         a->rba = &pp->rb;
+         a->rbb = &rp->rb;
+         a->conet = cosf( inf->conet )-0.0001f;
+         
+         /* Store constraint in local space vectors */
+         m3x3_mulv( c->rba->to_local, inf->conevx, a->conevx );
+         m3x3_mulv( c->rba->to_local, inf->conevy, a->conevy );
+         m3x3_mulv( c->rbb->to_local, inf->coneva, a->coneva );
+         v3_copy( c->lca, a->view_offset );
          
-         struct mdl_node *pnode = mdl_node_from_id( src, bone->orig_node );
-         struct classtype_bone *bone_inf = mdl_get_entdata( src, pnode );
+         v3_cross( inf->coneva, inf->conevy, a->conevxb );
+         m3x3_mulv( c->rbb->to_local, a->conevxb, a->conevxb );
 
-         rp->use_limits = bone_inf->use_limits;
-         v3_copy( bone_inf->angle_limits[0], rp->limits[0] );
-         v3_copy( bone_inf->angle_limits[1], rp->limits[1] );
+         v3_normalize( a->conevxb );
+         v3_normalize( a->conevx );
+         v3_normalize( a->conevy );
+         v3_normalize( a->coneva );
 
-         rb_init( &rp->rb );
+         a->conevx[3] = v3_length( inf->conevx );
+         a->conevy[3] = v3_length( inf->conevy );
+
+         rp->use_limits = 1;
       }
    }
 }
@@ -85,8 +200,8 @@ VG_STATIC void player_model_copy_ragdoll(void)
       struct ragdoll_part *part = &mdl->ragdoll[i];
       m4x3f offset;
       m3x3_identity(offset);
-      v3_negate( part->offset, offset[3] );
-      m4x3_mul( part->rb.to_world, offset, mdl->sk.final_mtx[part->bone_id] );
+      m4x3_mul( part->rb.to_world, part->inv_collider_mtx, 
+                  mdl->sk.final_mtx[part->bone_id] );
    }
 
    skeleton_apply_inverses( &mdl->sk );
@@ -105,11 +220,15 @@ VG_STATIC void player_ragdoll_copy_model( v3f v )
 
       v3f pos, offset;
       u32 bone = part->bone_id;
-      
+
       m4x3_mulv( mdl->sk.final_mtx[bone], mdl->sk.bones[bone].co, pos );
-      m3x3_mulv( mdl->sk.final_mtx[bone], part->offset, offset );
+      m3x3_mulv( mdl->sk.final_mtx[bone], part->collider_mtx[3], offset );
       v3_add( pos, offset, part->rb.co );
-      m3x3_q( mdl->sk.final_mtx[bone], part->rb.q );
+
+      m3x3f r;
+      m3x3_mul( mdl->sk.final_mtx[bone], part->collider_mtx, r );
+      m3x3_q( r, part->rb.q );
+
       v3_copy( v, part->rb.v );
       v3_zero( part->rb.w );
       
@@ -123,9 +242,6 @@ VG_STATIC void player_ragdoll_copy_model( v3f v )
 VG_STATIC void player_debug_ragdoll(void)
 {
    struct player_model *mdl = &player.mdl;
-
-   for( u32 i=0; i<mdl->ragdoll_count; i ++ )
-      rb_debug( &mdl->ragdoll[i].rb, 0xff00ff00 );
 }
 
 /*
@@ -134,84 +250,99 @@ VG_STATIC void player_debug_ragdoll(void)
 VG_STATIC void player_ragdoll_iter(void)
 {
    struct player_model *mdl = &player.mdl;
-   rb_solver_reset();
 
+   int run_sim = 0;
+   ragdoll_frame ++;
+
+   if( ragdoll_frame >= k_ragdoll_div )
+   {
+      ragdoll_frame = 0;
+      run_sim = 1;
+   }
+
+   rb_solver_reset();
    for( int i=0; i<mdl->ragdoll_count; i ++ )
       rb_collide( &mdl->ragdoll[i].rb, &world.rb_geo );
 
+   /* 
+    * COLLISION DETECTION
+    */
+   for( int i=0; i<mdl->ragdoll_count-1; i ++ )
+   {
+      for( int j=i+1; j<mdl->ragdoll_count; j ++ )
+      {
+         if( mdl->ragdoll[j].parent != i )
+            rb_collide( &mdl->ragdoll[i].rb, &mdl->ragdoll[j].rb );
+      }
+   }
+
+   /*
+    * PRESOLVE
+    */
    rb_presolve_contacts( rb_contact_buffer, rb_contact_count );
+   rb_presolve_swingtwist_constraints( mdl->cone_constraints,
+                                       mdl->cone_constraints_count );
+
+   /* 
+    * DEBUG
+    */
+   if( k_ragdoll_debug_collider )
+   {
+      for( u32 i=0; i<mdl->ragdoll_count; i ++ )
+         rb_debug( &mdl->ragdoll[i].rb, mdl->ragdoll[i].colour );
+   }
 
-   v3f rv;
+   if( k_ragdoll_debug_constraints )
+   {
+      rb_debug_position_constraints( mdl->position_constraints, 
+                                     mdl->position_constraints_count );
+
+      rb_debug_swingtwist_constraints( mdl->cone_constraints,
+                                       mdl->cone_constraints_count );
+   }
 
 #if 0
-   float shoe_vel[2] = {0.0f,0.0f};
-   for( int i=0; i<2; i++ )
-      if( mdl->shoes[i] )
-         shoe_vel[i] = v3_length( mdl->ragdoll[i].rb.v );
-#endif
-   
    for( int j=0; j<mdl->ragdoll_count; j++ )
    {
       struct ragdoll_part *pj = &mdl->ragdoll[j];
       struct skeleton_bone *bj = &mdl->sk.bones[pj->bone_id];
 
-      if( pj->parent != 0xffffffff )
+      if( run_sim )
       {
-         struct ragdoll_part *pp = &mdl->ragdoll[pj->parent];
-         struct skeleton_bone *bp = &mdl->sk.bones[pp->bone_id];
-
-         v3f lca, lcb;
-         v3_negate( pj->offset, lca );
-         v3_add( bp->co, pp->offset, lcb );
-         v3_sub( bj->co, lcb, lcb );
-
-         rb_debug_constraint_position( &pj->rb, lca, &pp->rb, lcb );
-
-         if( pj->use_limits )
-         {
-            rb_debug_constraint_limits( &pj->rb, &pp->rb, lca, pj->limits );
-         }
+         v4f plane = {0.0f,1.0f,0.0f,0.0f};
+         rb_effect_simple_bouyency( &pj->rb, plane, k_ragdoll_floatyiness,
+                                                    k_ragdoll_floatydrag );
       }
-
-      v4f plane = {0.0f,1.0f,0.0f,0.0f};
-      rb_effect_simple_bouyency( &pj->rb, plane, k_ragdoll_floatyiness,
-                                                 k_ragdoll_floatydrag );
    }
+#endif
 
-   /* CONSTRAINTS */
-   for( int i=0; i<10; i++ )
+   /*
+    * SOLVE CONSTRAINTS 
+    */
+   if( run_sim )
    {
-      rb_solve_contacts( rb_contact_buffer, rb_contact_count );
-
-      for( int j=0; j<mdl->ragdoll_count; j++ )
+      for( int i=0; i<25; i++ )
       {
-         struct ragdoll_part *pj = &mdl->ragdoll[j];
-         struct skeleton_bone *bj = &mdl->sk.bones[pj->bone_id];
+         rb_solve_contacts( rb_contact_buffer, rb_contact_count );
+         rb_solve_swingtwist_constraints( mdl->cone_constraints, 
+                                          mdl->cone_constraints_count );
+         rb_solve_position_constraints( mdl->position_constraints, 
+                                        mdl->position_constraints_count );
+      }
 
-         if( (pj->parent != 0xffffffff) && pj->use_limits )
-         {
-            struct ragdoll_part *pp = &mdl->ragdoll[pj->parent];
-            struct skeleton_bone *bp = &mdl->sk.bones[pp->bone_id];
+      for( int i=0; i<mdl->ragdoll_count; i++ )
+         rb_iter( &mdl->ragdoll[i].rb );
 
-            v3f lca, lcb;
-            v3_negate( pj->offset, lca );
-            v3_add( bp->co, pp->offset, lcb );
-            v3_sub( bj->co, lcb, lcb );
+      for( int i=0; i<mdl->ragdoll_count; i++ )
+         rb_update_transform( &mdl->ragdoll[i].rb );
 
-            rb_constraint_position( &pj->rb, lca, &pp->rb, lcb );
+      rb_correct_swingtwist_constraints( mdl->cone_constraints, 
+                                         mdl->cone_constraints_count, 0.25f );
 
-            rb_constraint_limits( &pj->rb, lca, &pp->rb, lcb, pj->limits );
-         }
-      }
+      rb_correct_position_constraints( mdl->position_constraints,
+                                       mdl->position_constraints_count, 0.5f );
    }
 
-   /* INTEGRATION */
-   for( int i=0; i<mdl->ragdoll_count; i++ )
-      rb_iter( &mdl->ragdoll[i].rb );
-   
-   /* SHOES */
-   for( int i=0; i<mdl->ragdoll_count; i++ )
-      rb_update_transform( &mdl->ragdoll[i].rb );
 }
 
 #endif /* PLAYER_RAGDOLL_H */
diff --git a/rigidbody.h b/rigidbody.h
index aa8d4f8..f4d6ef9 100644
--- a/rigidbody.h
+++ b/rigidbody.h
@@ -10,7 +10,6 @@
 #include "common.h"
 #include "bvh.h"
 #include "scene.h"
-#include "distq.h"
 
 #include <math.h>
 
@@ -29,14 +28,41 @@ VG_STATIC bh_system bh_system_rigidbodies;
 VG_STATIC const float 
    k_rb_rate          = (1.0/VG_TIMESTEP_FIXED),
    k_rb_delta         = (1.0/k_rb_rate),
-   k_friction         = 0.6f,
-   k_damp_linear      = 0.05f,               /* scale velocity 1/(1+x) */
+   k_friction         = 0.4f,
+   k_damp_linear      = 0.1f,               /* scale velocity 1/(1+x) */
    k_damp_angular     = 0.1f,                /* scale angular  1/(1+x) */
+   k_penetration_slop = 0.01f,
+   k_inertia_scale    = 8.0f,
+   k_phys_baumgarte   = 0.2f;
+
+VG_STATIC float
    k_limit_bias       = 0.02f,
-   k_joint_bias       = 0.08f,               /* positional joints */
    k_joint_correction = 0.01f,
-   k_penetration_slop = 0.01f,
-   k_inertia_scale    = 4.0f;
+   k_joint_impulse    = 1.0f,
+   k_joint_bias       = 0.08f;               /* positional joints */
+
+VG_STATIC void rb_register_cvar(void)
+{
+   vg_convar_push( (struct vg_convar){
+      .name = "k_limit_bias", .data = &k_limit_bias,
+      .data_type = k_convar_dtype_f32, .opt_f32 = {.clamp = 0}, .persistent = 1
+   });
+
+   vg_convar_push( (struct vg_convar){
+      .name = "k_joint_bias", .data = &k_joint_bias,
+      .data_type = k_convar_dtype_f32, .opt_f32 = {.clamp = 0}, .persistent = 1
+   });
+
+   vg_convar_push( (struct vg_convar){
+      .name = "k_joint_correction", .data = &k_joint_correction,
+      .data_type = k_convar_dtype_f32, .opt_f32 = {.clamp = 0}, .persistent = 1
+   });
+
+   vg_convar_push( (struct vg_convar){
+      .name = "k_joint_impulse", .data = &k_joint_impulse,
+      .data_type = k_convar_dtype_f32, .opt_f32 = {.clamp = 0}, .persistent = 1
+   });
+}
 
 /* 
  * -----------------------------------------------------------------------------
@@ -112,6 +138,30 @@ VG_STATIC struct contact
 rb_contact_buffer[256];
 VG_STATIC int rb_contact_count = 0;
 
+typedef struct rb_constr_pos rb_constr_pos;
+typedef struct rb_constr_swingtwist rb_constr_swingtwist;
+
+struct rb_constr_pos
+{
+   rigidbody *rba, *rbb;
+   v3f lca, lcb;
+};
+
+struct rb_constr_swingtwist
+{
+   rigidbody *rba, *rbb;
+
+   v4f conevx, conevy; /* relative to rba */
+   v3f view_offset,    /* relative to rba */
+       coneva, conevxb;/* relative to rbb */
+
+   int tangent_violation, axis_violation;
+   v3f axis, tangent_axis, tangent_target, axis_target;
+
+   float conet;
+   float tangent_mass, axis_mass;
+};
+
 /*
  * -----------------------------------------------------------------------------
  *                               Math Utils
@@ -155,8 +205,8 @@ VG_STATIC void rb_debug_contact( rb_ct *ct )
    if( ct->type != k_contact_type_disabled )
    {
       v3f p1;
-      v3_muladds( ct->co, ct->n, 0.1f, p1 );
-      vg_line_pt3( ct->co, 0.025f, 0xff0000ff );
+      v3_muladds( ct->co, ct->n, 0.05f, p1 );
+      vg_line_pt3( ct->co, 0.0025f, 0xff0000ff );
       vg_line( ct->co, p1, 0xffffffff );
    }
 }
@@ -397,8 +447,8 @@ VG_STATIC void rb_init( rigidbody *rb )
             h = rb->inf.capsule.height;
       volume = sphere_volume( r ) + VG_PIf * r*r * (h - r*2.0f);
 
-      v3_fill( rb->bbx[0], -rb->inf.sphere.radius );
-      v3_fill( rb->bbx[1],  rb->inf.sphere.radius );
+      v3_fill( rb->bbx[0], -r );
+      v3_fill( rb->bbx[1],  r );
       rb->bbx[0][1] = -h;
       rb->bbx[1][1] =  h;
    }
@@ -778,7 +828,7 @@ struct capsule_manifold
  * on the oriented object which created this pair.
  */
 VG_STATIC void rb_capsule_manifold( v3f pa, v3f pb, float t, float r, 
-                                 capsule_manifold *manifold )
+                                    capsule_manifold *manifold )
 {
    v3f delta;
    v3_sub( pa, pb, delta );
@@ -911,6 +961,9 @@ VG_STATIC int rb_capsule_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
 
 VG_STATIC int rb_capsule_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
 {
+   if( !box_overlap( rba->bbx_world, rbb->bbx_world ) )
+      return 0;
+
    float ha = rba->inf.capsule.height,
          hb = rbb->inf.capsule.height,
          ra = rba->inf.capsule.radius,
@@ -1483,10 +1536,147 @@ VG_STATIC int rb_box_scene( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
    return count;
 }
 
+/*
+ * Generates up to two contacts; optimised for the most stable manifold
+ */
+VG_STATIC int rb_capsule_triangle( rigidbody *rba, rigidbody *rbb, 
+                                   v3f tri[3], rb_ct *buf )
+{
+   float h = rba->inf.capsule.height,
+         r = rba->inf.capsule.radius;
+   
+   v3f pc, p0w, p1w;
+   v3_muladds( rba->co, rba->up, -h*0.5f+r, p0w );
+   v3_muladds( rba->co, rba->up,  h*0.5f-r, p1w );
+
+   capsule_manifold manifold;
+   rb_capsule_manifold_init( &manifold );
+   
+   v3f c0, c1;
+   closest_on_triangle_1( p0w, tri, c0 );
+   closest_on_triangle_1( p1w, tri, c1 );
+
+   v3f d0, d1, da;
+   v3_sub( c0, p0w, d0 );
+   v3_sub( c1, p1w, d1 );
+   v3_sub( p1w, p0w, da );
+   
+   v3_normalize(d0);
+   v3_normalize(d1);
+   v3_normalize(da);
+
+   if( v3_dot( da, d0 ) <= 0.01f )
+      rb_capsule_manifold( p0w, c0, 0.0f, r, &manifold );
+
+   if( v3_dot( da, d1 ) >= -0.01f )
+      rb_capsule_manifold( p1w, c1, 1.0f, r, &manifold );
+
+   for( int i=0; i<3; i++ )
+   {
+      int i0 = i,
+          i1 = (i+1)%3;
+
+      v3f ca, cb;
+      float ta, tb;
+      closest_segment_segment( p0w, p1w, tri[i0], tri[i1], &ta, &tb, ca, cb );
+      rb_capsule_manifold( ca, cb, ta, r, &manifold );
+   }
+
+   v3f v0, v1, n;
+   v3_sub( tri[1], tri[0], v0 );
+   v3_sub( tri[2], tri[0], v1 );
+   v3_cross( v0, v1, n );
+   v3_normalize( n );
+
+   int count = rb_capsule_manifold_done( rba, rbb, &manifold, buf );
+   for( int i=0; i<count; i++ )
+      v3_copy( n, buf[i].n );
+
+   return count;
+}
+
+VG_STATIC int rb_capsule_scene( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+#if 0
+   float h = rba->inf.capsule.height,
+         r = rba->inf.capsule.radius,
+         g = 90.8f;
+   
+   v3f p[2];
+   v3_muladds( rba->co, rba->up, -h*0.5f+r, p[0] );
+   v3_muladds( rba->co, rba->up,  h*0.5f-r, p[1] );
+
+   int count = 0;
+
+
+   for( int i=0; i<2; i++ )
+   {
+      if( p[i][1] < g + r )
+      {
+         rb_ct *ct = &buf[ count ++ ];
+
+         v3_copy( p[i], ct->co );
+         ct->p = r - (p[i][1]-g);
+         ct->co[1] -= r;
+         v3_copy( (v3f){0.0f,1.0f,0.0f}, ct->n );
+         ct->rba = rba;
+         ct->rbb = rbb;
+         ct->type = k_contact_type_default;
+      }
+   }
+
+   return count;
+
+#else
+   scene *sc = rbb->inf.scene.bh_scene->user;
+
+   bh_iter it;
+   bh_iter_init( 0, &it );
+   int idx;
+
+   int count = 0;
+   
+   while( bh_next( rbb->inf.scene.bh_scene, &it, rba->bbx_world, &idx ) )
+   {
+      u32 *ptri = &sc->arrindices[ idx*3 ];
+      v3f tri[3];
+
+      for( int j=0; j<3; j++ )
+         v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
+      
+      buf[ count ].element_id = ptri[0];
+
+#if 0
+      vg_line( tri[0],tri[1],0x70ff6000 );
+      vg_line( tri[1],tri[2],0x70ff6000 );
+      vg_line( tri[2],tri[0],0x70ff6000 );
+#endif
+
+      int contact = rb_capsule_triangle( rba, rbb, tri, buf+count );
+      count += contact;
+
+      if( count == 16 )
+      {
+         vg_warn("Exceeding capsule_vs_scene capacity. Geometry too dense!\n");
+         return count;
+      }
+   }
+
+   return count;
+#endif
+}
+
+VG_STATIC int rb_scene_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+   return rb_capsule_scene( rbb, rba, buf );
+}
+
 VG_STATIC int RB_MATRIX_ERROR( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
 {
+#if 0
    vg_error( "Collision type is unimplemented between types %d and %d\n",
              rba->type, rbb->type );
+#endif
 
    return 0;
 }
@@ -1516,8 +1706,8 @@ VG_STATIC int (*rb_jump_table[4][4])( rigidbody *a, rigidbody *b, rb_ct *buf ) =
     /* box */        /* Sphere */       /* Capsule */       /* Mesh */
   { RB_MATRIX_ERROR, rb_box_sphere,     rb_box_capsule,     rb_box_scene    },
   { rb_sphere_box,   rb_sphere_sphere,  rb_sphere_capsule,  rb_sphere_scene },
-  { rb_capsule_box,  rb_capsule_sphere, rb_capsule_capsule, RB_MATRIX_ERROR },
-  { rb_scene_box,    RB_MATRIX_ERROR,   RB_MATRIX_ERROR,    RB_MATRIX_ERROR }
+  { rb_capsule_box,  rb_capsule_sphere, rb_capsule_capsule, rb_capsule_scene },
+  { rb_scene_box,    RB_MATRIX_ERROR,   rb_scene_capsule,   RB_MATRIX_ERROR }
 };
 
 VG_STATIC int rb_collide( rigidbody *rba, rigidbody *rbb )
@@ -1619,21 +1809,15 @@ VG_STATIC void rb_presolve_contacts( rb_ct *buffer, int len )
 }
 
 /*
- * Creates relative contact velocity vector, and offsets between each body
+ * Creates relative contact velocity vector
  */
-VG_STATIC void rb_rcv( rb_ct *ct, v3f rv, v3f da, v3f db )
+VG_STATIC void rb_rcv( rigidbody *rba, rigidbody *rbb, v3f ra, v3f rb, v3f rv )
 {
-   rigidbody *rba = ct->rba,
-             *rbb = ct->rbb;
-
-   v3_sub( ct->co, rba->co, da );
-   v3_sub( ct->co, rbb->co, db );
-   
    v3f rva, rvb;
-   v3_cross( rba->w, da, rva );
-   v3_add( rba->v, rva, rva );
-   v3_cross( rbb->w, db, rvb );
-   v3_add( rbb->v, rvb, rvb );
+   v3_cross( rba->w, ra, rva );
+   v3_add(   rba->v, rva, rva );
+   v3_cross( rbb->w, rb, rvb );
+   v3_add(   rbb->v, rvb, rvb );
 
    v3_sub( rva, rvb, rv );
 }
@@ -1663,10 +1847,10 @@ VG_STATIC void rb_solve_contacts( rb_ct *buf, int len )
    {
       struct contact *ct = &buf[i];
 
-      rigidbody *rb = ct->rba;
-
-      v3f rv, da, db;
-      rb_rcv( ct, rv, da, db );
+      v3f rv, ra, rb;
+      v3_sub( ct->co, ct->rba->co, ra );
+      v3_sub( ct->co, ct->rbb->co, rb );
+      rb_rcv( ct->rba, ct->rbb, ra, rb, rv );
       
       /* Friction */
       for( int j=0; j<2; j++ )
@@ -1681,14 +1865,14 @@ VG_STATIC void rb_solve_contacts( rb_ct *buf, int len )
 
          v3f impulse;
          v3_muls( ct->t[j],  lambda, impulse );
-         rb_linear_impulse( ct->rba, da, impulse );
+         rb_linear_impulse( ct->rba, ra, impulse );
          
          v3_muls( ct->t[j], -lambda, impulse );
-         rb_linear_impulse( ct->rbb, db, impulse );
+         rb_linear_impulse( ct->rbb, rb, impulse );
       }
 
       /* Normal */
-      rb_rcv( ct, rv, da, db );
+      rb_rcv( ct->rba, ct->rbb, ra, rb, rv );
       float     vn = v3_dot( rv, ct->n ),
             lambda = ct->normal_mass * (-vn + ct->bias);
 
@@ -1698,10 +1882,10 @@ VG_STATIC void rb_solve_contacts( rb_ct *buf, int len )
 
       v3f impulse;
       v3_muls( ct->n,  lambda, impulse );
-      rb_linear_impulse( ct->rba, da, impulse );
+      rb_linear_impulse( ct->rba, ra, impulse );
 
       v3_muls( ct->n, -lambda, impulse );
-      rb_linear_impulse( ct->rbb, db, impulse );
+      rb_linear_impulse( ct->rbb, rb, impulse );
    }
 }
 
@@ -1711,220 +1895,468 @@ VG_STATIC void rb_solve_contacts( rb_ct *buf, int len )
  * -----------------------------------------------------------------------------
  */
 
-VG_STATIC void draw_angle_limit( v3f c, v3f major, v3f minor, 
-                              float amin, float amax, float measured,
-                              u32 colour )
+VG_STATIC void rb_debug_position_constraints( rb_constr_pos *buffer, int len )
 {
-   float f = 0.05f;
-   v3f ay, ax;
-   v3_muls( major, f, ay );
-   v3_muls( minor, f, ax );
-
-   for( int x=0; x<16; x++ )
+   for( int i=0; i<len; i++ )
    {
-      float t0 = (float)x / 16.0f,
-            t1 = (float)(x+1) / 16.0f,
-            a0 = vg_lerpf( amin, amax, t0 ),
-            a1 = vg_lerpf( amin, amax, t1 );
+      rb_constr_pos *constr = &buffer[i];
+      rigidbody *rba = constr->rba, *rbb = constr->rbb;
+
+      v3f wca, wcb;
+      m3x3_mulv( rba->to_world, constr->lca, wca );
+      m3x3_mulv( rbb->to_world, constr->lcb, wcb );
 
       v3f p0, p1;
-      v3_muladds(  c, ay, cosf(a0), p0 );
-      v3_muladds( p0, ax, sinf(a0), p0 );
-      v3_muladds(  c, ay, cosf(a1), p1 );
-      v3_muladds( p1, ax, sinf(a1), p1 );
+      v3_add( wca, rba->co, p0 );
+      v3_add( wcb, rbb->co, p1 );
+      vg_line_pt3( p0, 0.0025f, 0xff000000 );
+      vg_line_pt3( p1, 0.0025f, 0xffffffff );
+      vg_line2( p0, p1, 0xff000000, 0xffffffff );
+   }
+}
+
+VG_STATIC void rb_presolve_swingtwist_constraints( rb_constr_swingtwist *buf,
+                                                   int len )
+{
+   float size = 0.12f;
+
+   for( int i=0; i<len; i++ )
+   {
+      rb_constr_swingtwist *st = &buf[ i ];
       
-      vg_line( p0, p1, colour );
+      v3f vx, vy, va, vxb, axis, center;
 
-      if( x == 0 )
-         vg_line( c, p0, colour );
-      if( x == 15 )
-         vg_line( c, p1, colour );
-   }
+      m3x3_mulv( st->rba->to_world, st->conevx, vx );
+      m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
+      m3x3_mulv( st->rba->to_world, st->conevy, vy );
+      m3x3_mulv( st->rbb->to_world, st->coneva, va );
+      m4x3_mulv( st->rba->to_world, st->view_offset, center );
+      v3_cross( vy, vx, axis );
+
+      /* Constraint violated ? */
+      float fx = v3_dot( vx, va ),     /* projection world */
+            fy = v3_dot( vy, va ),
+            fn = v3_dot( va, axis ),
+
+            rx = st->conevx[3],        /* elipse radii */
+            ry = st->conevy[3],
+
+            lx = fx/rx,                /* projection local (fn==lz) */
+            ly = fy/ry;
+
+      st->tangent_violation = ((lx*lx + ly*ly) > fn*fn) || (fn <= 0.0f);
+      if( st->tangent_violation )
+      {
+         /* Calculate a good position and the axis to solve on */
+         v2f closest, tangent, 
+             p = { fx/fabsf(fn), fy/fabsf(fn) };
+
+         closest_point_elipse( p, (v2f){rx,ry}, closest );
+         tangent[0] = -closest[1] / (ry*ry);
+         tangent[1] =  closest[0] / (rx*rx);
+         v2_normalize( tangent );
+
+         v3f v0, v1;
+         v3_muladds( axis, vx, closest[0], v0 );
+         v3_muladds( v0, vy, closest[1], v0 );
+         v3_normalize( v0 );
+
+         v3_muls( vx, tangent[0], v1 );
+         v3_muladds( v1, vy, tangent[1], v1 );
+
+         v3_copy( v0, st->tangent_target );
+         v3_copy( v1, st->tangent_axis );
+
+         /* calculate mass */
+         v3f aIw, bIw;
+         m3x3_mulv( st->rba->iIw, st->tangent_axis, aIw );
+         m3x3_mulv( st->rbb->iIw, st->tangent_axis, bIw );
+         st->tangent_mass = 1.0f / (v3_dot( st->tangent_axis, aIw ) +
+                                    v3_dot( st->tangent_axis, bIw ));
+
+         float angle = v3_dot( va, st->tangent_target );
+      }
+
+      v3f refaxis;
+      v3_cross( vy, va, refaxis );  /* our default rotation */
+      v3_normalize( refaxis );
+
+      float angle = v3_dot( refaxis, vxb );
+      st->axis_violation = fabsf(angle) < st->conet;
 
-   v3f p2;
-   v3_muladds(  c, ay, cosf(measured)*1.2f, p2 );
-   v3_muladds( p2, ax, sinf(measured)*1.2f, p2 );
-   vg_line( c, p2, colour );
+      if( st->axis_violation )
+      {
+         v3f dir_test;
+         v3_cross( refaxis, vxb, dir_test );
+
+         if( v3_dot(dir_test, va) < 0.0f )
+            st->axis_violation = -st->axis_violation;
+
+         float newang = (float)st->axis_violation * acosf(st->conet-0.0001f);
+
+         v3f refaxis_up;
+         v3_cross( va, refaxis, refaxis_up );
+         v3_muls( refaxis_up, sinf(newang), st->axis_target );
+         v3_muladds( st->axis_target, refaxis, -cosf(newang), st->axis_target );
+
+         /* calculate mass */
+         v3_copy( va, st->axis );
+         v3f aIw, bIw;
+         m3x3_mulv( st->rba->iIw, st->axis, aIw );
+         m3x3_mulv( st->rbb->iIw, st->axis, bIw );
+         st->axis_mass = 1.0f / (v3_dot( st->axis, aIw ) +
+                                 v3_dot( st->axis, bIw ));
+      }
+   }
 }
 
-VG_STATIC void rb_debug_constraint_limits( rigidbody *ra, rigidbody *rb, v3f lca,
-                                        v3f limits[2] )
+VG_STATIC void rb_debug_swingtwist_constraints( rb_constr_swingtwist *buf, 
+                                                int len )
 {
-   v3f ax, ay, az, bx, by, bz;
-   m3x3_mulv( ra->to_world, (v3f){1.0f,0.0f,0.0f}, ax );
-   m3x3_mulv( ra->to_world, (v3f){0.0f,1.0f,0.0f}, ay );
-   m3x3_mulv( ra->to_world, (v3f){0.0f,0.0f,1.0f}, az );
-   m3x3_mulv( rb->to_world, (v3f){1.0f,0.0f,0.0f}, bx );
-   m3x3_mulv( rb->to_world, (v3f){0.0f,1.0f,0.0f}, by );
-   m3x3_mulv( rb->to_world, (v3f){0.0f,0.0f,1.0f}, bz );
+   float size = 0.12f;
+
+   for( int i=0; i<len; i++ )
+   {
+      rb_constr_swingtwist *st = &buf[ i ];
+      
+      v3f vx, vxb, vy, va, axis, center;
+
+      m3x3_mulv( st->rba->to_world, st->conevx, vx );
+      m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
+      m3x3_mulv( st->rba->to_world, st->conevy, vy );
+      m3x3_mulv( st->rbb->to_world, st->coneva, va );
+      m4x3_mulv( st->rba->to_world, st->view_offset, center );
+      v3_cross( vy, vx, axis );
+
+      float rx = st->conevx[3],        /* elipse radii */
+            ry = st->conevy[3];
+
+      v3f p0, p1;
+      v3_muladds( center, va, size, p1 );
+      vg_line( center, p1, 0xffffffff );
+      vg_line_pt3( p1, 0.00025f, 0xffffffff );
+
+      if( st->tangent_violation )
+      {
+         v3_muladds( center, st->tangent_target, size, p0 );
+
+         vg_line( center, p0, 0xff00ff00 );
+         vg_line_pt3( p0, 0.00025f, 0xff00ff00 );
+         vg_line( p1, p0, 0xff000000 );
+      }
+      
+      for( int x=0; x<32; x++ )
+      {
+         float t0 = ((float)x * (1.0f/32.0f)) * VG_TAUf,
+               t1 = (((float)x+1.0f) * (1.0f/32.0f)) * VG_TAUf,
+               c0 = cosf( t0 ),
+               s0 = sinf( t0 ),
+               c1 = cosf( t1 ),
+               s1 = sinf( t1 );
+
+         v3f v0, v1;
+         v3_muladds( axis, vx, c0*rx, v0 );
+         v3_muladds( v0,   vy, s0*ry, v0 );
+         v3_muladds( axis, vx, c1*rx, v1 );
+         v3_muladds( v1,   vy, s1*ry, v1 );
+
+         v3_normalize( v0 );
+         v3_normalize( v1 );
+
+         v3_muladds( center, v0, size, p0 );
+         v3_muladds( center, v1, size, p1 );
+
+         u32 col0r = fabsf(c0) * 255.0f,
+             col0g = fabsf(s0) * 255.0f,
+             col1r = fabsf(c1) * 255.0f,
+             col1g = fabsf(s1) * 255.0f,
+             col   = st->tangent_violation? 0xff0000ff: 0xff000000,
+             col0  = col | (col0r<<16) | (col0g << 8),
+             col1  = col | (col1r<<16) | (col1g << 8);
+
+         vg_line2( center, p0, VG__NONE, col0 );
+         vg_line2( p0, p1, col0, col1 );
+      }
 
-   v2f px, py, pz;
-   px[0] = v3_dot( ay, by );
-   px[1] = v3_dot( az, by );
+      /* Draw twist */
+      v3_muladds( center, va, size, p0 );
+      v3_muladds( p0, vxb, size, p1 );
 
-   py[0] = v3_dot( az, bz );
-   py[1] = v3_dot( ax, bz );
+      vg_line( p0, p1, 0xff0000ff );
 
-   pz[0] = v3_dot( ax, bx );
-   pz[1] = v3_dot( ay, bx );
+      if( st->axis_violation )
+      {
+         v3_muladds( p0, st->axis_target, size*1.25f, p1 );
+         vg_line( p0, p1, 0xffffff00 );
+         vg_line_pt3( p1, 0.0025f, 0xffffff80 );
+      }
 
-   float r0 = atan2f( px[1], px[0] ),
-         r1 = atan2f( py[1], py[0] ),
-         r2 = atan2f( pz[1], pz[0] );
+      v3f refaxis;
+      v3_cross( vy, va, refaxis );  /* our default rotation */
+      v3_normalize( refaxis );
+      v3f refaxis_up;
+      v3_cross( va, refaxis, refaxis_up );
+      float newang = acosf(st->conet-0.0001f);
 
-   v3f c;
-   m4x3_mulv( ra->to_world, lca, c );
-   draw_angle_limit( c, ay, az, limits[0][0], limits[1][0], r0, 0xff0000ff );
-   draw_angle_limit( c, az, ax, limits[0][1], limits[1][1], r1, 0xff00ff00 );
-   draw_angle_limit( c, ax, ay, limits[0][2], limits[1][2], r2, 0xffff0000 );
+      v3_muladds( p0, refaxis_up, sinf(newang)*size, p1 );
+      v3_muladds( p1, refaxis, -cosf(newang)*size, p1 );
+      vg_line( p0, p1, 0xff000000 );
+
+      v3_muladds( p0, refaxis_up, sinf(-newang)*size, p1 );
+      v3_muladds( p1, refaxis, -cosf(-newang)*size, p1 );
+      vg_line( p0, p1, 0xff404040 );
+   }
 }
 
-VG_STATIC void rb_limit_cure( rigidbody *ra, rigidbody *rb, v3f axis, float d )
+/*
+ * Solve a list of positional constraints
+ */
+VG_STATIC void rb_solve_position_constraints( rb_constr_pos *buf, int len )
 {
-   if( d != 0.0f )
+   for( int i=0; i<len; i++ )
    {
-      float avx = v3_dot( ra->w, axis ) - v3_dot( rb->w, axis );
-      float joint_mass = rb->inv_mass + ra->inv_mass;
-      joint_mass = 1.0f/joint_mass;
+      rb_constr_pos *constr = &buf[i];
+      rigidbody *rba = constr->rba, *rbb = constr->rbb;
 
-      float bias = (k_limit_bias * k_rb_rate) * d,
-            lambda = -(avx + bias) * joint_mass;
-
-      /* Angular velocity */
       v3f wa, wb;
-      v3_muls( axis,  lambda * ra->inv_mass, wa );
-      v3_muls( axis, -lambda * rb->inv_mass, wb );
+      m3x3_mulv( rba->to_world, constr->lca, wa );
+      m3x3_mulv( rbb->to_world, constr->lcb, wb );
 
-      v3_add( ra->w, wa, ra->w );
-      v3_add( rb->w, wb, rb->w );
+      m3x3f ssra, ssrat, ssrb, ssrbt;
+      
+      m3x3_skew_symetric( ssrat, wa );
+      m3x3_skew_symetric( ssrbt, wb );
+      m3x3_transpose( ssrat, ssra );
+      m3x3_transpose( ssrbt, ssrb );
+
+      v3f b, b_wa, b_wb, b_a, b_b;
+      m3x3_mulv( ssra, rba->w, b_wa );
+      m3x3_mulv( ssrb, rbb->w, b_wb );
+      v3_add( rba->v, b_wa, b );
+      v3_sub( b, rbb->v, b );
+      v3_sub( b, b_wb, b );
+      v3_muls( b, -1.0f, b );
+
+      m3x3f invMa, invMb;
+      m3x3_diagonal( invMa, rba->inv_mass );
+      m3x3_diagonal( invMb, rbb->inv_mass );
+
+      m3x3f ia, ib;
+      m3x3_mul( ssra, rba->iIw, ia );
+      m3x3_mul( ia, ssrat, ia );
+      m3x3_mul( ssrb, rbb->iIw, ib );
+      m3x3_mul( ib, ssrbt, ib );
+
+      m3x3f cma, cmb;
+      m3x3_add( invMa, ia, cma );
+      m3x3_add( invMb, ib, cmb );
+
+      m3x3f A;
+      m3x3_add( cma, cmb, A );
+
+      /* Solve Ax = b ( A^-1*b = x ) */
+      v3f impulse;
+      m3x3f invA;
+      m3x3_inv( A, invA );
+      m3x3_mulv( invA, b, impulse );
+
+      v3f delta_va, delta_wa, delta_vb, delta_wb;
+      m3x3f iwa, iwb;
+      m3x3_mul( rba->iIw, ssrat, iwa );
+      m3x3_mul( rbb->iIw, ssrbt, iwb );
+
+      m3x3_mulv( invMa, impulse, delta_va );
+      m3x3_mulv( invMb, impulse, delta_vb );
+      m3x3_mulv( iwa, impulse, delta_wa );
+      m3x3_mulv( iwb, impulse, delta_wb );
+
+      v3_add( rba->v, delta_va, rba->v );
+      v3_add( rba->w, delta_wa, rba->w );
+      v3_sub( rbb->v, delta_vb, rbb->v );
+      v3_sub( rbb->w, delta_wb, rbb->w );
    }
 }
 
-VG_STATIC void rb_constraint_limits( rigidbody *ra, v3f lca, 
-                                  rigidbody *rb, v3f lcb, v3f limits[2] )
+VG_STATIC void rb_solve_swingtwist_constraints( rb_constr_swingtwist *buf, 
+                                                int len )
 {
-   v3f ax, ay, az, bx, by, bz;
-   m3x3_mulv( ra->to_world, (v3f){1.0f,0.0f,0.0f}, ax );
-   m3x3_mulv( ra->to_world, (v3f){0.0f,1.0f,0.0f}, ay );
-   m3x3_mulv( ra->to_world, (v3f){0.0f,0.0f,1.0f}, az );
-   m3x3_mulv( rb->to_world, (v3f){1.0f,0.0f,0.0f}, bx );
-   m3x3_mulv( rb->to_world, (v3f){0.0f,1.0f,0.0f}, by );
-   m3x3_mulv( rb->to_world, (v3f){0.0f,0.0f,1.0f}, bz );
+   float size = 0.12f;
+
+   for( int i=0; i<len; i++ )
+   {
+      rb_constr_swingtwist *st = &buf[ i ];
+
+      if( !st->axis_violation )
+         continue;
+
+      float rv = v3_dot( st->axis, st->rbb->w ) - 
+                 v3_dot( st->axis, st->rba->w );
+
+      if( rv * (float)st->axis_violation > 0.0f )
+         continue;
+
+      v3f impulse, wa, wb;
+      v3_muls( st->axis, rv*st->axis_mass, impulse );
+      m3x3_mulv( st->rba->iIw, impulse, wa );
+      v3_add( st->rba->w, wa, st->rba->w );
 
-   v2f px, py, pz;
-   px[0] = v3_dot( ay, by );
-   px[1] = v3_dot( az, by );
+      v3_muls( impulse, -1.0f, impulse );
+      m3x3_mulv( st->rbb->iIw, impulse, wb );
+      v3_add( st->rbb->w, wb, st->rbb->w );
 
-   py[0] = v3_dot( az, bz );
-   py[1] = v3_dot( ax, bz );
+      float rv2 = v3_dot( st->axis, st->rbb->w ) - 
+                  v3_dot( st->axis, st->rba->w );
+   }
 
-   pz[0] = v3_dot( ax, bx );
-   pz[1] = v3_dot( ay, bx );
+   for( int i=0; i<len; i++ )
+   {
+      rb_constr_swingtwist *st = &buf[ i ];
 
-   float r0 = atan2f( px[1], px[0] ),
-         r1 = atan2f( py[1], py[0] ),
-         r2 = atan2f( pz[1], pz[0] );
+      if( !st->tangent_violation )
+         continue;
 
-   /* calculate angle deltas */
-   float dx = 0.0f, dy = 0.0f, dz = 0.0f;
+      float rv = v3_dot( st->tangent_axis, st->rbb->w ) - 
+                 v3_dot( st->tangent_axis, st->rba->w );
 
-   if( r0 < limits[0][0] ) dx = limits[0][0] - r0;
-   if( r0 > limits[1][0] ) dx = limits[1][0] - r0;
-   if( r1 < limits[0][1] ) dy = limits[0][1] - r1;
-   if( r1 > limits[1][1] ) dy = limits[1][1] - r1;
-   if( r2 < limits[0][2] ) dz = limits[0][2] - r2;
-   if( r2 > limits[1][2] ) dz = limits[1][2] - r2;
+      if( rv > 0.0f )
+         continue;
+
+      v3f impulse, wa, wb;
+      v3_muls( st->tangent_axis, rv*st->tangent_mass, impulse );
+      m3x3_mulv( st->rba->iIw, impulse, wa );
+      v3_add( st->rba->w, wa, st->rba->w );
 
-   v3f wca, wcb;
-   m3x3_mulv( ra->to_world, lca, wca );
-   m3x3_mulv( rb->to_world, lcb, wcb );
+      v3_muls( impulse, -1.0f, impulse );
+      m3x3_mulv( st->rbb->iIw, impulse, wb );
+      v3_add( st->rbb->w, wb, st->rbb->w );
 
-   rb_limit_cure( ra, rb, ax, dx );
-   rb_limit_cure( ra, rb, ay, dy );
-   rb_limit_cure( ra, rb, az, dz );
+      float rv2 = v3_dot( st->tangent_axis, st->rbb->w ) - 
+                  v3_dot( st->tangent_axis, st->rba->w );
+   }
 }
 
-VG_STATIC void rb_debug_constraint_position( rigidbody *ra, v3f lca,
-                                          rigidbody *rb, v3f lcb )
+VG_STATIC void rb_solve_constr_angle( rigidbody *rba, rigidbody *rbb,
+                                      v3f ra, v3f rb )
 {
-   v3f wca, wcb;
-   m3x3_mulv( ra->to_world, lca, wca );
-   m3x3_mulv( rb->to_world, lcb, wcb );
+   m3x3f ssra, ssrb, ssrat, ssrbt;
+   m3x3f cma, cmb;
+
+   m3x3_skew_symetric( ssrat, ra );
+   m3x3_skew_symetric( ssrbt, rb );
+   m3x3_transpose( ssrat, ssra );
+   m3x3_transpose( ssrbt, ssrb );
+
+   m3x3_mul( ssra, rba->iIw, cma );
+   m3x3_mul( cma, ssrat, cma );
+   m3x3_mul( ssrb, rbb->iIw, cmb );
+   m3x3_mul( cmb, ssrbt, cmb );
+
+   m3x3f A, invA;
+   m3x3_add( cma, cmb, A );
+   m3x3_inv( A, invA );
+
+   v3f b_wa, b_wb, b;
+   m3x3_mulv( ssra, rba->w, b_wa );
+   m3x3_mulv( ssrb, rbb->w, b_wb );
+   v3_add( b_wa, b_wb, b );
+   v3_negate( b, b );
+
+   v3f impulse;
+   m3x3_mulv( invA, b, impulse );
+
+   v3f delta_wa, delta_wb;
+   m3x3f iwa, iwb;
+   m3x3_mul( rba->iIw, ssrat, iwa );
+   m3x3_mul( rbb->iIw, ssrbt, iwb );
+   m3x3_mulv( iwa, impulse, delta_wa );
+   m3x3_mulv( iwb, impulse, delta_wb );
+   v3_add( rba->w, delta_wa, rba->w );
+   v3_sub( rbb->w, delta_wb, rbb->w );
+}
 
-   v3f p0, p1;
-   v3_add( wca, ra->co, p0 );
-   v3_add( wcb, rb->co, p1 );
-   vg_line_pt3( p0, 0.005f, 0xffffff00 );
-   vg_line_pt3( p1, 0.005f, 0xffffff00 );
-   vg_line( p0, p1, 0xffffff00 );
+/*
+ * Correct position constraint drift errors
+ * [ 0.0 <= amt <= 1.0 ]: the correction amount
+ */
+VG_STATIC void rb_correct_position_constraints( rb_constr_pos *buf, int len, 
+                                                float amt )
+{
+   for( int i=0; i<len; i++ )
+   {
+      rb_constr_pos *constr = &buf[i];
+      rigidbody *rba = constr->rba, *rbb = constr->rbb;
+
+      v3f p0, p1, d;
+      m3x3_mulv( rba->to_world, constr->lca, p0 );
+      m3x3_mulv( rbb->to_world, constr->lcb, p1 );
+      v3_add( rba->co, p0, p0 );
+      v3_add( rbb->co, p1, p1 );
+      v3_sub( p1, p0, d );
+
+      v3_muladds( rbb->co, d, -1.0f * amt, rbb->co );
+      rb_update_transform( rbb );
+   }
 }
 
-VG_STATIC void rb_constraint_position( rigidbody *ra, v3f lca,
-                                    rigidbody *rb, v3f lcb )
+VG_STATIC void rb_correct_swingtwist_constraints( rb_constr_swingtwist *buf, 
+                                                  int len, float amt )
 {
-   /* C = (COa + Ra*LCa) - (COb + Rb*LCb) = 0 */
-   v3f wca, wcb;
-   m3x3_mulv( ra->to_world, lca, wca );
-   m3x3_mulv( rb->to_world, lcb, wcb );
+   for( int i=0; i<len; i++ )
+   {
+      rb_constr_swingtwist *st = &buf[i];
 
-   v3f rcv;
-   v3_sub( ra->v, rb->v, rcv );
+      if( !st->tangent_violation )
+         continue;
 
-   v3f rcv_Ra, rcv_Rb;
-   v3_cross( ra->w, wca, rcv_Ra );
-   v3_cross( rb->w, wcb, rcv_Rb );
-   v3_add( rcv_Ra, rcv, rcv );
-   v3_sub( rcv, rcv_Rb, rcv );
+      v3f va;
+      m3x3_mulv( st->rbb->to_world, st->coneva, va );
 
-   v3f delta;
-   v3f p0, p1;
-   v3_add( wca, ra->co, p0 );
-   v3_add( wcb, rb->co, p1 );
-   v3_sub( p1, p0, delta );
+      float angle = v3_dot( va, st->tangent_target );
 
-   float dist2 = v3_length2( delta );
+      if( fabsf(angle) < 0.9999f )
+      {
+         v3f axis;
+         v3_cross( va, st->tangent_target, axis );
 
-   if( dist2 > 0.00001f )
+         v4f correction;
+         q_axis_angle( correction, axis, acosf(angle) * amt );
+         q_mul( correction, st->rbb->q, st->rbb->q );
+         rb_update_transform( st->rbb );
+      }
+   }
+
+   for( int i=0; i<len; i++ )
    {
-      float dist = sqrtf(dist2);
-      v3_muls( delta, 1.0f/dist, delta );
+      rb_constr_swingtwist *st = &buf[i];
 
-      float joint_mass = rb->inv_mass + ra->inv_mass;
+      if( !st->axis_violation )
+         continue;
 
-      v3f raCn, rbCn, raCt, rbCt;
-      v3_cross( wca, delta, raCn );
-      v3_cross( wcb, delta, rbCn );
-      
-      /* orient inverse inertia tensors */
-      v3f raCnI, rbCnI;
-      m3x3_mulv( ra->iIw, raCn, raCnI );
-      m3x3_mulv( rb->iIw, rbCn, rbCnI );
-      joint_mass += v3_dot( raCn, raCnI );
-      joint_mass += v3_dot( rbCn, rbCnI );
-      joint_mass = 1.0f/joint_mass;
+      v3f vxb;
+      m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
 
-      float vd = v3_dot( rcv, delta ),
-            bias = -(k_joint_bias * k_rb_rate) * dist,
-            lambda = -(vd + bias) * joint_mass;
+      float angle = v3_dot( vxb, st->axis_target );
 
-      v3f impulse;
-      v3_muls( delta,  lambda, impulse );
-      rb_linear_impulse( ra, wca, impulse );
-      v3_muls( delta, -lambda, impulse );
-      rb_linear_impulse( rb, wcb, impulse );
-
-      /* 'fake' snap */
-      v3_muladds( ra->co, delta,  dist * k_joint_correction, ra->co );
-      v3_muladds( rb->co, delta, -dist * k_joint_correction, rb->co );
+      if( fabsf(angle) < 0.9999f )
+      {
+         v3f axis;
+         v3_cross( vxb, st->axis_target, axis );
+
+         v4f correction;
+         q_axis_angle( correction, axis, acosf(angle) * amt );
+         q_mul( correction, st->rbb->q, st->rbb->q );
+         rb_update_transform( st->rbb );
+      }
    }
 }
 
+
 /* 
  * Effectors
  */
 
 VG_STATIC void rb_effect_simple_bouyency( rigidbody *ra, v4f plane, 
-                                       float amt, float drag )
+                                          float amt, float drag )
 {
    /* float */
    float depth  = v3_dot( plane, ra->co ) - plane[3],
diff --git a/scene.h b/scene.h
index 7fc29f3..8fffe97 100644
--- a/scene.h
+++ b/scene.h
@@ -4,7 +4,6 @@
 #include "common.h"
 #include "model.h"
 #include "bvh.h"
-#include "distq.h"
 
 typedef struct scene scene;
 
diff --git a/skaterift.c b/skaterift.c
index f31e1f6..9d72bec 100644
--- a/skaterift.c
+++ b/skaterift.c
@@ -2,7 +2,7 @@
  * =============================================================================
  *
  * Copyright  .        . .       -----, ,----- ,---.   .---.
- * 2021-2022  |\      /| |           /  |      |    | |    /|
+ * 2021-2023  |\      /| |           /  |      |    | |    /|
  *            | \    / | +--        /   +----- +---'  |   / |
  *            |  \  /  | |         /    |      |   \  |  /  |
  *            |   \/   | |        /     |      |    \ | /   |
diff --git a/skeleton.h b/skeleton.h
index 9f715ef..4f35d58 100644
--- a/skeleton.h
+++ b/skeleton.h
@@ -14,16 +14,14 @@ struct skeleton
       v3f co, end;
       u32 parent;
 
-      int deform, ik;
+      u32 flags;
       int defer;
 
       mdl_keyframe kf;
 
       u32 orig_node;
 
-      int collider;
       boxf hitbox;
-
       const char *name;
    }
    *bones;
@@ -155,7 +153,8 @@ VG_STATIC int should_apply_bone( struct skeleton *skele, u32 id, anim_apply type
 
    if( type == k_anim_apply_defer_ik )
    {
-      if( (sp->ik && !sb->ik) || sp->defer )
+      if( ((sp->flags & k_bone_flag_ik) && !(sb->flags & k_bone_flag_ik)) 
+          || sp->defer )
       {
          sb->defer = 1;
          return 0;
@@ -185,7 +184,7 @@ VG_STATIC void skeleton_apply_pose( struct skeleton *skele, mdl_keyframe *pose,
 {
    m4x3_identity( skele->final_mtx[0] );
    skele->bones[0].defer = 0;
-   skele->bones[0].ik = 0;
+   skele->bones[0].flags &= ~k_bone_flag_ik;
 
    for( int i=1; i<skele->bone_count; i++ )
    {
@@ -454,18 +453,16 @@ VG_STATIC void skeleton_setup( struct skeleton *skele,
 
             struct skeleton_bone *sb = &skele->bones[bone_count];
             struct classtype_bone *bone_inf = mdl_get_entdata( mdl, pnode );
-            int is_ik = bone_inf->ik_target;
 
             v3_copy( pnode->co, sb->co );
             v3_copy( pnode->s, sb->end );
             sb->parent = pnode->parent-skeleton_root;
             sb->name   = mdl_pstr( mdl, pnode->pstr_name );
-            sb->deform = bone_inf->deform;
+            sb->flags  = bone_inf->flags;
 
-            if( is_ik )
+            if( sb->flags & k_bone_flag_ik )
             {
-               sb->ik = 1; /* TODO: place into new IK array */
-               skele->bones[ sb->parent ].ik = 1;
+               skele->bones[ sb->parent ].flags |= k_bone_flag_ik;
                
                if( ik_count == skele->ik_count )
                {
@@ -479,16 +476,11 @@ VG_STATIC void skeleton_setup( struct skeleton *skele,
                ik->target = bone_inf->ik_target;
                ik->pole = bone_inf->ik_pole;
             }
-            else
-            {
-               sb->ik = 0;
-            }
 
-            sb->collider = bone_inf->collider;
             sb->orig_node = i;
             box_copy( bone_inf->hitbox, sb->hitbox );
 
-            if( bone_inf->collider )
+            if( bone_inf->flags & k_bone_flag_collider_any )
             {
                if( collider_count == skele->collider_count )
                {
@@ -538,7 +530,7 @@ VG_STATIC void skeleton_setup( struct skeleton *skele,
    v3_zero( skele->bones[0].co );
    v3_copy( (v3f){0.0f,1.0f,0.0f}, skele->bones[0].end );
    skele->bones[0].parent = 0xffffffff;
-   skele->bones[0].collider = 0;
+   skele->bones[0].flags = 0;
    skele->bones[0].name = "[root]";
    
    /* process animation quick refs */
@@ -575,9 +567,9 @@ VG_STATIC void skeleton_debug( struct skeleton *skele )
       m4x3_mulv( skele->final_mtx[i], p0, p0 );
       m4x3_mulv( skele->final_mtx[i], p1, p1 );
 
-      if( sb->deform )
+      if( sb->flags & k_bone_flag_deform )
       {
-         if( sb->ik )
+         if( sb->flags & k_bone_flag_ik )
          {
             vg_line( p0, p1, 0xff0000ff );
          }