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
++ )
60 if( !strcmp( skele
->bones
[i
].name
, name
))
64 vg_error( "skeleton_bone_id( *, \"%s\" );\n", name
);
65 vg_fatal_exit_loop( "Bone does not exist\n" );
70 VG_STATIC
void keyframe_copy_pose( mdl_keyframe
*kfa
, mdl_keyframe
*kfb
, int num
)
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
, float t
,
80 mdl_keyframe
*kfd
, int count
)
84 keyframe_copy_pose( kfa
, kfd
, count
);
89 keyframe_copy_pose( kfb
, kfd
, count
);
93 for( int i
=0; i
<count
; i
++ )
95 v3_lerp( kfa
[i
].co
, kfb
[i
].co
, t
, kfd
[i
].co
);
96 q_nlerp( kfa
[i
].q
, kfb
[i
].q
, t
, kfd
[i
].q
);
97 v3_lerp( kfa
[i
].s
, kfb
[i
].s
, t
, kfd
[i
].s
);
101 VG_STATIC
void skeleton_lerp_pose( struct skeleton
*skele
,
102 mdl_keyframe
*kfa
, mdl_keyframe
*kfb
, float t
,
105 keyframe_lerp_pose( kfa
, kfb
, t
, kfd
, skele
->bone_count
-1 );
109 * Sample animation between 2 closest frames using time value. Output is a
110 * keyframe buffer that is allocated with an appropriate size
112 VG_STATIC
void skeleton_sample_anim( struct skeleton
*skele
,
113 struct skeleton_anim
*anim
,
115 mdl_keyframe
*output
)
117 float animtime
= time
*anim
->rate
;
119 u32 frame
= ((u32
)animtime
) % anim
->length
,
120 next
= (frame
+1) % anim
->length
;
122 float t
= vg_fractf( animtime
);
124 mdl_keyframe
*base
= anim
->anim_data
+ (skele
->bone_count
-1)*frame
,
125 *nbase
= anim
->anim_data
+ (skele
->bone_count
-1)*next
;
127 skeleton_lerp_pose( skele
, base
, nbase
, t
, output
);
130 VG_STATIC
int skeleton_sample_anim_clamped( struct skeleton
*skele
,
131 struct skeleton_anim
*anim
,
133 mdl_keyframe
*output
)
135 float end
= (float)(anim
->length
-1) / anim
->rate
;
136 skeleton_sample_anim( skele
, anim
, vg_minf( end
, time
), output
);
144 typedef enum anim_apply
147 k_anim_apply_defer_ik
,
148 k_anim_apply_deffered_only
152 VG_STATIC
int should_apply_bone( struct skeleton
*skele
, u32 id
, anim_apply type
)
154 struct skeleton_bone
*sb
= &skele
->bones
[ id
],
155 *sp
= &skele
->bones
[ sb
->parent
];
157 if( type
== k_anim_apply_defer_ik
)
159 if( ((sp
->flags
& k_bone_flag_ik
) && !(sb
->flags
& k_bone_flag_ik
))
171 else if( type
== k_anim_apply_deffered_only
)
183 * Apply block of keyframes to skeletons final pose
185 VG_STATIC
void skeleton_apply_pose( struct skeleton
*skele
, mdl_keyframe
*pose
,
186 anim_apply passtype
)
188 m4x3_identity( skele
->final_mtx
[0] );
189 skele
->bones
[0].defer
= 0;
190 skele
->bones
[0].flags
&= ~k_bone_flag_ik
;
192 for( int i
=1; i
<skele
->bone_count
; i
++ )
194 struct skeleton_bone
*sb
= &skele
->bones
[i
],
195 *sp
= &skele
->bones
[ sb
->parent
];
197 if( !should_apply_bone( skele
, i
, passtype
) )
206 v3_sub( skele
->bones
[i
].co
, skele
->bones
[sb
->parent
].co
, temp_delta
);
209 mdl_keyframe
*kf
= &pose
[i
-1];
210 q_m3x3( kf
->q
, posemtx
);
211 v3_copy( kf
->co
, posemtx
[3] );
212 v3_add( temp_delta
, posemtx
[3], posemtx
[3] );
215 m4x3_mul( skele
->final_mtx
[ sb
->parent
], posemtx
, skele
->final_mtx
[i
] );
220 * creates the reference inverse matrix for an IK bone, as it has an initial
221 * intrisic rotation based on the direction that the IK is setup..
223 VG_STATIC
void skeleton_inverse_for_ik( struct skeleton
*skele
,
225 u32 id
, m3x3f inverse
)
227 v3_copy( ivaxis
, inverse
[0] );
228 v3_copy( skele
->bones
[id
].end
, inverse
[1] );
229 v3_normalize( inverse
[1] );
230 v3_cross( inverse
[0], inverse
[1], inverse
[2] );
231 m3x3_transpose( inverse
, inverse
);
235 * Creates inverse rotation matrices which the IK system uses.
237 VG_STATIC
void skeleton_create_inverses( struct skeleton
*skele
)
239 /* IK: inverse 'plane-bone space' axis '(^axis,^bone,...)[base] */
240 for( int 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
259 VG_STATIC
void skeleton_apply_transform( struct skeleton
*skele
, m4x3f transform
)
261 for( int 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( int i
=0; i
<skele
->bone_count
; i
++ )
276 struct skeleton_bone
*sb
= &skele
->bones
[i
];
278 m3x3_identity( inverse
);
279 v3_negate( sb
->co
, inverse
[3] );
281 m4x3_mul( skele
->final_mtx
[i
], inverse
, skele
->final_mtx
[i
] );
286 * Apply all IK modifiers (2 bone ik reference from blender is supported)
288 VG_STATIC
void skeleton_apply_ik_pass( struct skeleton
*skele
)
290 for( int i
=0; i
<skele
->ik_count
; i
++ )
292 struct skeleton_ik
*ik
= &skele
->ik
[i
];
294 v3f v0
, /* base -> target */
295 v1
, /* base -> pole */
302 v3_copy( skele
->final_mtx
[ik
->lower
][3], co_base
);
303 v3_copy( skele
->final_mtx
[ik
->target
][3], co_target
);
304 v3_copy( skele
->final_mtx
[ik
->pole
][3], co_pole
);
306 v3_sub( co_target
, co_base
, v0
);
307 v3_sub( co_pole
, co_base
, v1
);
308 v3_cross( v0
, v1
, vaxis
);
309 v3_normalize( vaxis
);
311 v3_cross( vaxis
, v0
, v1
);
313 /* localize problem into [x:v0,y:v1] 2d plane */
314 v2f base
= { v3_dot( v0
, co_base
), v3_dot( v1
, co_base
) },
315 end
= { v3_dot( v0
, co_target
), v3_dot( v1
, co_target
) },
318 /* Compute angles (basic trig)*/
320 v2_sub( end
, base
, delta
);
323 l1
= v3_length( skele
->bones
[ik
->lower
].end
),
324 l2
= v3_length( skele
->bones
[ik
->upper
].end
),
325 d
= vg_clampf( v2_length(delta
), fabsf(l1
- l2
), l1
+l2
-0.00001f
),
326 c
= acosf( (l1
*l1
+ d
*d
- l2
*l2
) / (2.0f
*l1
*d
) ),
327 rot
= atan2f( delta
[1], delta
[0] ) + c
- VG_PIf
/2.0f
;
329 knee
[0] = sinf(-rot
) * l1
;
330 knee
[1] = cosf(-rot
) * l1
;
332 m4x3_identity( skele
->final_mtx
[ik
->lower
] );
333 m4x3_identity( skele
->final_mtx
[ik
->upper
] );
335 /* create rotation matrix */
337 v3_muladds( co_base
, v0
, knee
[0], co_knee
);
338 v3_muladds( co_knee
, v1
, knee
[1], co_knee
);
339 vg_line( co_base
, co_knee
, 0xff00ff00 );
342 v3_copy( vaxis
, transform
[0] );
343 v3_muls( v0
, knee
[0], transform
[1] );
344 v3_muladds( transform
[1], v1
, knee
[1], transform
[1] );
345 v3_normalize( transform
[1] );
346 v3_cross( transform
[0], transform
[1], transform
[2] );
347 v3_copy( co_base
, transform
[3] );
349 m3x3_mul( transform
, ik
->ia
, transform
);
350 m4x3_copy( transform
, skele
->final_mtx
[ik
->lower
] );
352 /* upper/knee bone */
353 v3_copy( vaxis
, transform
[0] );
354 v3_sub( co_target
, co_knee
, transform
[1] );
355 v3_normalize( transform
[1] );
356 v3_cross( transform
[0], transform
[1], transform
[2] );
357 v3_copy( co_knee
, transform
[3] );
359 m3x3_mul( transform
, ik
->ib
, transform
);
360 m4x3_copy( transform
, skele
->final_mtx
[ik
->upper
] );
365 * Applies the typical operations that you want for an IK rig:
366 * Pose, IK, Pose(deferred), Inverses, Transform
368 VG_STATIC
void skeleton_apply_standard( struct skeleton
*skele
, mdl_keyframe
*pose
,
371 skeleton_apply_pose( skele
, pose
, k_anim_apply_defer_ik
);
372 skeleton_apply_ik_pass( skele
);
373 skeleton_apply_pose( skele
, pose
, k_anim_apply_deffered_only
);
374 skeleton_apply_inverses( skele
);
375 skeleton_apply_transform( skele
, transform
);
379 * Get an animation by name
381 VG_STATIC
struct skeleton_anim
*skeleton_get_anim( struct skeleton
*skele
,
384 for( int i
=0; i
<skele
->anim_count
; i
++ )
386 struct skeleton_anim
*anim
= &skele
->anims
[i
];
388 if( !strcmp( anim
->name
, name
) )
392 vg_error( "skeleton_get_anim( *, \"%s\" )\n", name
);
393 vg_fatal_exit_loop( "Invalid animation name\n" );
398 VG_STATIC
void skeleton_alloc_from( struct skeleton
*skele
,
400 struct classtype_skeleton
*inf
)
402 skele
->bone_count
= inf
->channels
;
403 skele
->ik_count
= inf
->ik_count
;
404 skele
->collider_count
= inf
->collider_count
;
405 skele
->anim_count
= inf
->anim_count
;
407 u32 bone_size
= sizeof(struct skeleton_bone
) * skele
->bone_count
,
408 ik_size
= sizeof(struct skeleton_ik
) * skele
->ik_count
,
409 mtx_size
= sizeof(m4x3f
) * skele
->bone_count
,
410 anim_size
= sizeof(struct skeleton_anim
) * skele
->anim_count
;
412 skele
->bones
= vg_linear_alloc( lin_alloc
, bone_size
);
413 skele
->ik
= vg_linear_alloc( lin_alloc
, ik_size
);
414 skele
->final_mtx
= vg_linear_alloc( lin_alloc
, mtx_size
);
415 skele
->anims
= vg_linear_alloc( lin_alloc
, anim_size
);
418 VG_STATIC
void skeleton_fatal_err(void)
420 vg_fatal_exit_loop( "Skeleton setup failed" );
423 /* Setup an animated skeleton from model. mdl's metadata should stick around */
424 VG_STATIC
void skeleton_setup( struct skeleton
*skele
,
425 void *lin_alloc
, mdl_context
*mdl
)
427 u32 bone_count
= 1, skeleton_root
= 0, ik_count
= 0, collider_count
= 0;
428 skele
->bone_count
= 0;
430 skele
->final_mtx
= NULL
;
433 struct classtype_skeleton
*inf
= NULL
;
435 for( u32 i
=0; i
<mdl
->info
.node_count
; i
++ )
437 mdl_node
*pnode
= mdl_node_from_id( mdl
, i
);
439 if( pnode
->classtype
== k_classtype_skeleton
)
441 inf
= mdl_get_entdata( mdl
, pnode
);
442 skeleton_alloc_from( skele
, lin_alloc
, inf
);
445 else if( skele
->bone_count
)
447 int is_bone
= pnode
->classtype
== k_classtype_bone
;
451 if( bone_count
== skele
->bone_count
)
453 vg_error( "too many bones (%u/%u) @%s!\n",
454 bone_count
, skele
->bone_count
,
455 mdl_pstr( mdl
, pnode
->pstr_name
));
457 skeleton_fatal_err();
460 struct skeleton_bone
*sb
= &skele
->bones
[bone_count
];
461 struct classtype_bone
*bone_inf
= mdl_get_entdata( mdl
, pnode
);
463 v3_copy( pnode
->co
, sb
->co
);
464 v3_copy( pnode
->s
, sb
->end
);
465 sb
->parent
= pnode
->parent
-skeleton_root
;
466 sb
->name
= mdl_pstr( mdl
, pnode
->pstr_name
);
467 sb
->flags
= bone_inf
->flags
;
469 if( sb
->flags
& k_bone_flag_ik
)
471 skele
->bones
[ sb
->parent
].flags
|= k_bone_flag_ik
;
473 if( ik_count
== skele
->ik_count
)
475 vg_error( "Too many ik bones, corrupt model file\n" );
476 skeleton_fatal_err();
479 struct skeleton_ik
*ik
= &skele
->ik
[ ik_count
++ ];
480 ik
->upper
= bone_count
;
481 ik
->lower
= sb
->parent
;
482 ik
->target
= bone_inf
->ik_target
;
483 ik
->pole
= bone_inf
->ik_pole
;
487 box_copy( bone_inf
->hitbox
, sb
->hitbox
);
489 if( bone_inf
->flags
& k_bone_flag_collider_any
)
491 if( collider_count
== skele
->collider_count
)
493 vg_error( "Too many collider bones\n" );
494 skeleton_fatal_err();
511 vg_error( "No skeleton in model\n" );
512 skeleton_fatal_err();
515 if( collider_count
!= skele
->collider_count
)
517 vg_error( "Loaded %u colliders out of %u\n", collider_count
,
518 skele
->collider_count
);
519 skeleton_fatal_err();
522 if( bone_count
!= skele
->bone_count
)
524 vg_error( "Loaded %u bones out of %u\n", bone_count
, skele
->bone_count
);
525 vg_fatal_exit_loop( "Skeleton setup failed" );
526 skeleton_fatal_err();
529 if( ik_count
!= skele
->ik_count
)
531 vg_error( "Loaded %u ik bones out of %u\n", ik_count
, skele
->ik_count
);
532 skeleton_fatal_err();
535 /* fill in implicit root bone */
536 v3_zero( skele
->bones
[0].co
);
537 v3_copy( (v3f
){0.0f
,1.0f
,0.0f
}, skele
->bones
[0].end
);
538 skele
->bones
[0].parent
= 0xffffffff;
539 skele
->bones
[0].flags
= 0;
540 skele
->bones
[0].name
= "[root]";
542 /* process animation quick refs */
543 for( int i
=0; i
<skele
->anim_count
; i
++ )
545 mdl_animation
*anim
= &mdl
->anim_buffer
[ inf
->anim_start
+ i
];
547 skele
->anims
[i
].rate
= anim
->rate
;
548 skele
->anims
[i
].length
= anim
->length
;
549 skele
->anims
[i
].name
= mdl_pstr(mdl
, anim
->pstr_name
);
550 skele
->anims
[i
].anim_data
= &mdl
->keyframe_buffer
[ anim
->offset
];
552 vg_info( "animation[ %f, %u ] '%s'\n", anim
->rate
,
554 skele
->anims
[i
].name
);
557 skeleton_create_inverses( skele
);
558 vg_success( "Loaded skeleton with %u bones\n", skele
->bone_count
);
559 vg_success( " %u colliders\n", skele
->collider_count
);
562 VG_STATIC
void skeleton_debug( struct skeleton
*skele
)
564 for( int i
=0; i
<skele
->bone_count
; i
++ )
566 struct skeleton_bone
*sb
= &skele
->bones
[i
];
569 v3_copy( sb
->co
, p0
);
570 v3_add( p0
, sb
->end
, p1
);
571 //vg_line( p0, p1, 0xffffffff );
573 m4x3_mulv( skele
->final_mtx
[i
], p0
, p0
);
574 m4x3_mulv( skele
->final_mtx
[i
], p1
, p1
);
576 if( sb
->flags
& k_bone_flag_deform
)
578 if( sb
->flags
& k_bone_flag_ik
)
580 vg_line( p0
, p1
, 0xff0000ff );
584 vg_line( p0
, p1
, 0xffcccccc );
588 vg_line( p0
, p1
, 0xff00ffff );
592 #endif /* SKELETON_H */