2 * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
36 mdl_keyframe
*anim_data
;
45 u32 lower
, upper
, target
, pole
;
56 VG_STATIC u32
skeleton_bone_id( struct skeleton
*skele
, const char *name
)
58 for( u32 i
=1; i
<skele
->bone_count
; i
++ ){
59 if( !strcmp( skele
->bones
[i
].name
, name
))
63 vg_error( "skeleton_bone_id( *, \"%s\" );\n", name
);
64 vg_fatal_exit_loop( "Bone does not exist\n" );
69 VG_STATIC
void keyframe_copy_pose( mdl_keyframe
*kfa
, mdl_keyframe
*kfb
,
72 for( int i
=0; i
<num
; i
++ )
77 * Lerp between two sets of keyframes and store in dest. Rotations use Nlerp.
79 VG_STATIC
void keyframe_lerp_pose( mdl_keyframe
*kfa
, mdl_keyframe
*kfb
,
80 float t
, mdl_keyframe
*kfd
, int count
)
83 keyframe_copy_pose( kfa
, kfd
, count
);
86 else if( t
>= 0.9999f
){
87 keyframe_copy_pose( kfb
, kfd
, count
);
91 for( int i
=0; i
<count
; i
++ ){
92 v3_lerp( kfa
[i
].co
, kfb
[i
].co
, t
, kfd
[i
].co
);
93 q_nlerp( kfa
[i
].q
, kfb
[i
].q
, t
, kfd
[i
].q
);
94 v3_lerp( kfa
[i
].s
, kfb
[i
].s
, t
, kfd
[i
].s
);
99 void skeleton_lerp_pose( struct skeleton
*skele
,
100 mdl_keyframe
*kfa
, mdl_keyframe
*kfb
, float t
,
103 keyframe_lerp_pose( kfa
, kfb
, t
, kfd
, skele
->bone_count
-1 );
106 VG_STATIC
void skeleton_copy_pose( struct skeleton
*skele
,
107 mdl_keyframe
*kfa
, mdl_keyframe
*kfd
)
109 keyframe_copy_pose( kfa
, kfd
, skele
->bone_count
-1 );
113 * Sample animation between 2 closest frames using time value. Output is a
114 * keyframe buffer that is allocated with an appropriate size
116 VG_STATIC
void skeleton_sample_anim( struct skeleton
*skele
,
117 struct skeleton_anim
*anim
,
119 mdl_keyframe
*output
)
121 float animtime
= time
*anim
->rate
;
123 u32 frame
= ((u32
)animtime
) % anim
->length
,
124 next
= (frame
+1) % anim
->length
;
126 float t
= vg_fractf( animtime
);
128 mdl_keyframe
*base
= anim
->anim_data
+ (skele
->bone_count
-1)*frame
,
129 *nbase
= anim
->anim_data
+ (skele
->bone_count
-1)*next
;
131 skeleton_lerp_pose( skele
, base
, nbase
, t
, output
);
134 VG_STATIC
int skeleton_sample_anim_clamped( struct skeleton
*skele
,
135 struct skeleton_anim
*anim
,
137 mdl_keyframe
*output
)
139 float end
= (float)(anim
->length
-1) / anim
->rate
;
140 skeleton_sample_anim( skele
, anim
, vg_minf( end
, time
), output
);
148 typedef enum anim_apply
151 k_anim_apply_defer_ik
,
152 k_anim_apply_deffered_only
157 int should_apply_bone( struct skeleton
*skele
, u32 id
, anim_apply type
)
159 struct skeleton_bone
*sb
= &skele
->bones
[ id
],
160 *sp
= &skele
->bones
[ sb
->parent
];
162 if( type
== k_anim_apply_defer_ik
){
163 if( ((sp
->flags
& k_bone_flag_ik
) && !(sb
->flags
& k_bone_flag_ik
))
174 else if( type
== k_anim_apply_deffered_only
){
185 * Apply block of keyframes to skeletons final pose
187 VG_STATIC
void skeleton_apply_pose( struct skeleton
*skele
, mdl_keyframe
*pose
,
188 anim_apply passtype
)
190 m4x3_identity( skele
->final_mtx
[0] );
191 skele
->bones
[0].defer
= 0;
192 skele
->bones
[0].flags
&= ~k_bone_flag_ik
;
194 for( u32 i
=1; i
<skele
->bone_count
; i
++ ){
195 struct skeleton_bone
*sb
= &skele
->bones
[i
],
196 *sp
= &skele
->bones
[sb
->parent
];
198 if( !should_apply_bone( skele
, i
, passtype
) )
207 v3_sub( skele
->bones
[i
].co
, skele
->bones
[sb
->parent
].co
, temp_delta
);
210 mdl_keyframe
*kf
= &pose
[i
-1];
211 q_m3x3( kf
->q
, posemtx
);
212 v3_copy( kf
->co
, posemtx
[3] );
213 v3_add( temp_delta
, posemtx
[3], posemtx
[3] );
216 m4x3_mul( skele
->final_mtx
[ sb
->parent
], posemtx
, skele
->final_mtx
[i
] );
221 * creates the reference inverse matrix for an IK bone, as it has an initial
222 * intrisic rotation based on the direction that the IK is setup..
224 VG_STATIC
void skeleton_inverse_for_ik( struct skeleton
*skele
,
226 u32 id
, m3x3f inverse
)
228 v3_copy( ivaxis
, inverse
[0] );
229 v3_copy( skele
->bones
[id
].end
, inverse
[1] );
230 v3_normalize( inverse
[1] );
231 v3_cross( inverse
[0], inverse
[1], inverse
[2] );
232 m3x3_transpose( inverse
, inverse
);
236 * Creates inverse rotation matrices which the IK system uses.
238 VG_STATIC
void skeleton_create_inverses( struct skeleton
*skele
)
240 /* IK: inverse 'plane-bone space' axis '(^axis,^bone,...)[base] */
241 for( u32 i
=0; i
<skele
->ik_count
; i
++ ){
242 struct skeleton_ik
*ik
= &skele
->ik
[i
];
245 v3f iv0
, iv1
, ivaxis
;
246 v3_sub( skele
->bones
[ik
->target
].co
, skele
->bones
[ik
->lower
].co
, iv0
);
247 v3_sub( skele
->bones
[ik
->pole
].co
, skele
->bones
[ik
->lower
].co
, iv1
);
248 v3_cross( iv0
, iv1
, ivaxis
);
249 v3_normalize( ivaxis
);
251 skeleton_inverse_for_ik( skele
, ivaxis
, ik
->lower
, ik
->ia
);
252 skeleton_inverse_for_ik( skele
, ivaxis
, ik
->upper
, ik
->ib
);
257 * Apply a model matrix to all bones, should be done last
260 void skeleton_apply_transform( struct skeleton
*skele
, m4x3f transform
)
262 for( u32 i
=0; i
<skele
->bone_count
; i
++ ){
263 struct skeleton_bone
*sb
= &skele
->bones
[i
];
264 m4x3_mul( transform
, skele
->final_mtx
[i
], skele
->final_mtx
[i
] );
269 * Apply an inverse matrix to all bones which maps vertices from bind space into
270 * bone relative positions
272 VG_STATIC
void skeleton_apply_inverses( struct skeleton
*skele
)
274 for( u32 i
=0; i
<skele
->bone_count
; i
++ ){
275 struct skeleton_bone
*sb
= &skele
->bones
[i
];
277 m3x3_identity( inverse
);
278 v3_negate( sb
->co
, inverse
[3] );
280 m4x3_mul( skele
->final_mtx
[i
], inverse
, skele
->final_mtx
[i
] );
285 * Apply all IK modifiers (2 bone ik reference from blender is supported)
287 VG_STATIC
void skeleton_apply_ik_pass( struct skeleton
*skele
)
289 for( u32 i
=0; i
<skele
->ik_count
; i
++ ){
290 struct skeleton_ik
*ik
= &skele
->ik
[i
];
292 v3f v0
, /* base -> target */
293 v1
, /* base -> pole */
300 v3_copy( skele
->final_mtx
[ik
->lower
][3], co_base
);
301 v3_copy( skele
->final_mtx
[ik
->target
][3], co_target
);
302 v3_copy( skele
->final_mtx
[ik
->pole
][3], co_pole
);
304 v3_sub( co_target
, co_base
, v0
);
305 v3_sub( co_pole
, co_base
, v1
);
306 v3_cross( v0
, v1
, vaxis
);
307 v3_normalize( vaxis
);
309 v3_cross( vaxis
, v0
, v1
);
311 /* localize problem into [x:v0,y:v1] 2d plane */
312 v2f base
= { v3_dot( v0
, co_base
), v3_dot( v1
, co_base
) },
313 end
= { v3_dot( v0
, co_target
), v3_dot( v1
, co_target
) },
316 /* Compute angles (basic trig)*/
318 v2_sub( end
, base
, delta
);
321 l1
= v3_length( skele
->bones
[ik
->lower
].end
),
322 l2
= v3_length( skele
->bones
[ik
->upper
].end
),
323 d
= vg_clampf( v2_length(delta
), fabsf(l1
- l2
), l1
+l2
-0.00001f
),
324 c
= acosf( (l1
*l1
+ d
*d
- l2
*l2
) / (2.0f
*l1
*d
) ),
325 rot
= atan2f( delta
[1], delta
[0] ) + c
- VG_PIf
/2.0f
;
327 knee
[0] = sinf(-rot
) * l1
;
328 knee
[1] = cosf(-rot
) * l1
;
330 m4x3_identity( skele
->final_mtx
[ik
->lower
] );
331 m4x3_identity( skele
->final_mtx
[ik
->upper
] );
333 /* create rotation matrix */
335 v3_muladds( co_base
, v0
, knee
[0], co_knee
);
336 v3_muladds( co_knee
, v1
, knee
[1], co_knee
);
337 vg_line( co_base
, co_knee
, 0xff00ff00 );
340 v3_copy( vaxis
, transform
[0] );
341 v3_muls( v0
, knee
[0], transform
[1] );
342 v3_muladds( transform
[1], v1
, knee
[1], transform
[1] );
343 v3_normalize( transform
[1] );
344 v3_cross( transform
[0], transform
[1], transform
[2] );
345 v3_copy( co_base
, transform
[3] );
347 m3x3_mul( transform
, ik
->ia
, transform
);
348 m4x3_copy( transform
, skele
->final_mtx
[ik
->lower
] );
350 /* upper/knee bone */
351 v3_copy( vaxis
, transform
[0] );
352 v3_sub( co_target
, co_knee
, transform
[1] );
353 v3_normalize( transform
[1] );
354 v3_cross( transform
[0], transform
[1], transform
[2] );
355 v3_copy( co_knee
, transform
[3] );
357 m3x3_mul( transform
, ik
->ib
, transform
);
358 m4x3_copy( transform
, skele
->final_mtx
[ik
->upper
] );
363 * Applies the typical operations that you want for an IK rig:
364 * Pose, IK, Pose(deferred), Inverses, Transform
366 VG_STATIC
void skeleton_apply_standard( struct skeleton
*skele
, mdl_keyframe
*pose
,
369 skeleton_apply_pose( skele
, pose
, k_anim_apply_defer_ik
);
370 skeleton_apply_ik_pass( skele
);
371 skeleton_apply_pose( skele
, pose
, k_anim_apply_deffered_only
);
372 skeleton_apply_inverses( skele
);
373 skeleton_apply_transform( skele
, transform
);
377 * Get an animation by name
379 VG_STATIC
struct skeleton_anim
*skeleton_get_anim( struct skeleton
*skele
,
382 for( u32 i
=0; i
<skele
->anim_count
; i
++ ){
383 struct skeleton_anim
*anim
= &skele
->anims
[i
];
385 if( !strcmp( anim
->name
, name
) )
389 vg_error( "skeleton_get_anim( *, \"%s\" )\n", name
);
390 vg_fatal_exit_loop( "Invalid animation name\n" );
395 VG_STATIC
void skeleton_alloc_from( struct skeleton
*skele
,
398 mdl_armature
*armature
)
400 skele
->bone_count
= armature
->bone_count
+1;
401 skele
->anim_count
= armature
->anim_count
;
403 skele
->collider_count
= 0;
405 for( u32 i
=0; i
<armature
->bone_count
; i
++ ){
406 mdl_bone
*bone
= mdl_arritm( &mdl
->bones
, armature
->bone_start
+i
);
408 if( bone
->flags
& k_bone_flag_ik
)
412 skele
->collider_count
++;
415 u32 bone_size
= sizeof(struct skeleton_bone
) * skele
->bone_count
,
416 ik_size
= sizeof(struct skeleton_ik
) * skele
->ik_count
,
417 mtx_size
= sizeof(m4x3f
) * skele
->bone_count
,
418 anim_size
= sizeof(struct skeleton_anim
) * skele
->anim_count
;
420 skele
->bones
= vg_linear_alloc( lin_alloc
, bone_size
);
421 skele
->ik
= vg_linear_alloc( lin_alloc
, ik_size
);
422 skele
->final_mtx
= vg_linear_alloc( lin_alloc
, mtx_size
);
423 skele
->anims
= vg_linear_alloc( lin_alloc
, anim_size
);
426 VG_STATIC
void skeleton_fatal_err(void)
428 vg_fatal_exit_loop( "Skeleton setup failed" );
431 /* Setup an animated skeleton from model. mdl's metadata should stick around */
432 VG_STATIC
void skeleton_setup( struct skeleton
*skele
,
433 void *lin_alloc
, mdl_context
*mdl
)
435 u32 ik_count
= 0, collider_count
= 0;
436 skele
->bone_count
= 0;
438 skele
->final_mtx
= NULL
;
441 if( !mdl
->armatures
.count
){
442 vg_error( "No skeleton in model\n" );
443 skeleton_fatal_err();
446 mdl_armature
*armature
= mdl_arritm( &mdl
->armatures
, 0 );
447 skeleton_alloc_from( skele
, lin_alloc
, mdl
, armature
);
449 for( u32 i
=0; i
<armature
->bone_count
; i
++ ){
450 mdl_bone
*bone
= mdl_arritm( &mdl
->bones
, armature
->bone_start
+i
);
451 struct skeleton_bone
*sb
= &skele
->bones
[i
+1];
453 v3_copy( bone
->co
, sb
->co
);
454 v3_copy( bone
->end
, sb
->end
);
456 sb
->parent
= bone
->parent
;
457 sb
->name
= mdl_pstr( mdl
, bone
->pstr_name
);
458 sb
->flags
= bone
->flags
;
459 sb
->collider
= bone
->collider
;
460 sb
->orig_bone
= bone
;
462 if( sb
->flags
& k_bone_flag_ik
){
463 skele
->bones
[ sb
->parent
].flags
|= k_bone_flag_ik
;
465 if( ik_count
== skele
->ik_count
){
466 vg_error( "Too many ik bones, corrupt model file\n" );
467 skeleton_fatal_err();
470 struct skeleton_ik
*ik
= &skele
->ik
[ ik_count
++ ];
472 ik
->lower
= bone
->parent
;
473 ik
->target
= bone
->ik_target
;
474 ik
->pole
= bone
->ik_pole
;
477 box_copy( bone
->hitbox
, sb
->hitbox
);
479 if( bone
->collider
){
480 if( collider_count
== skele
->collider_count
){
481 vg_error( "Too many collider bones\n" );
482 skeleton_fatal_err();
489 /* fill in implicit root bone */
490 v3_zero( skele
->bones
[0].co
);
491 v3_copy( (v3f
){0.0f
,1.0f
,0.0f
}, skele
->bones
[0].end
);
492 skele
->bones
[0].parent
= 0xffffffff;
493 skele
->bones
[0].flags
= 0;
494 skele
->bones
[0].name
= "[root]";
496 /* process animation quick refs */
497 for( u32 i
=0; i
<skele
->anim_count
; i
++ ){
498 mdl_animation
*anim
=
499 mdl_arritm( &mdl
->animations
, armature
->anim_start
+i
);
501 skele
->anims
[i
].rate
= anim
->rate
;
502 skele
->anims
[i
].length
= anim
->length
;
503 skele
->anims
[i
].name
= mdl_pstr(mdl
, anim
->pstr_name
);
504 skele
->anims
[i
].anim_data
=
505 mdl_arritm( &mdl
->keyframes
, anim
->offset
);
507 vg_info( "animation[ %f, %u ] '%s'\n", anim
->rate
,
509 skele
->anims
[i
].name
);
512 skeleton_create_inverses( skele
);
513 vg_success( "Loaded skeleton with %u bones\n", skele
->bone_count
);
514 vg_success( " %u colliders\n", skele
->collider_count
);
517 VG_STATIC
void skeleton_debug( struct skeleton
*skele
)
519 for( u32 i
=1; i
<skele
->bone_count
; i
++ ){
520 struct skeleton_bone
*sb
= &skele
->bones
[i
];
523 v3_copy( sb
->co
, p0
);
524 v3_add( p0
, sb
->end
, p1
);
526 m4x3_mulv( skele
->final_mtx
[i
], p0
, p0
);
527 m4x3_mulv( skele
->final_mtx
[i
], p1
, p1
);
529 if( sb
->flags
& k_bone_flag_deform
){
530 if( sb
->flags
& k_bone_flag_ik
){
531 vg_line( p0
, p1
, 0xff0000ff );
534 vg_line( p0
, p1
, 0xffcccccc );
538 vg_line( p0
, p1
, 0xff00ffff );
542 #endif /* SKELETON_H */