2 * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
38 mdl_keyframe
*anim_data
;
47 u32 lower
, upper
, target
, pole
;
58 VG_STATIC u32
skeleton_bone_id( struct skeleton
*skele
, const char *name
)
60 for( u32 i
=1; i
<skele
->bone_count
; i
++ )
62 if( !strcmp( skele
->bones
[i
].name
, name
))
69 VG_STATIC
void keyframe_copy_pose( mdl_keyframe
*kfa
, mdl_keyframe
*kfb
, int num
)
71 for( int i
=0; i
<num
; i
++ )
76 * Lerp between two sets of keyframes and store in dest. Rotations use Nlerp.
78 VG_STATIC
void keyframe_lerp_pose( mdl_keyframe
*kfa
, mdl_keyframe
*kfb
, float t
,
79 mdl_keyframe
*kfd
, int count
)
83 keyframe_copy_pose( kfa
, kfd
, count
);
88 keyframe_copy_pose( kfb
, kfd
, count
);
92 for( int i
=0; i
<count
; i
++ )
94 v3_lerp( kfa
[i
].co
, kfb
[i
].co
, t
, kfd
[i
].co
);
95 q_nlerp( kfa
[i
].q
, kfb
[i
].q
, t
, kfd
[i
].q
);
96 v3_lerp( kfa
[i
].s
, kfb
[i
].s
, t
, kfd
[i
].s
);
100 VG_STATIC
void skeleton_lerp_pose( struct skeleton
*skele
,
101 mdl_keyframe
*kfa
, mdl_keyframe
*kfb
, float t
,
104 keyframe_lerp_pose( kfa
, kfb
, t
, kfd
, skele
->bone_count
-1 );
108 * Sample animation between 2 closest frames using time value. Output is a
109 * keyframe buffer that is allocated with an appropriate size
111 VG_STATIC
void skeleton_sample_anim( struct skeleton
*skele
,
112 struct skeleton_anim
*anim
,
114 mdl_keyframe
*output
)
116 float animtime
= time
*anim
->rate
;
118 u32 frame
= ((u32
)animtime
) % anim
->length
,
119 next
= (frame
+1) % anim
->length
;
121 float t
= vg_fractf( animtime
);
123 mdl_keyframe
*base
= anim
->anim_data
+ (skele
->bone_count
-1)*frame
,
124 *nbase
= anim
->anim_data
+ (skele
->bone_count
-1)*next
;
126 skeleton_lerp_pose( skele
, base
, nbase
, t
, output
);
129 VG_STATIC
int skeleton_sample_anim_clamped( struct skeleton
*skele
,
130 struct skeleton_anim
*anim
,
132 mdl_keyframe
*output
)
134 float end
= (float)(anim
->length
-1) / anim
->rate
;
135 skeleton_sample_anim( skele
, anim
, vg_minf( end
, time
), output
);
143 typedef enum anim_apply
146 k_anim_apply_defer_ik
,
147 k_anim_apply_deffered_only
151 VG_STATIC
int should_apply_bone( struct skeleton
*skele
, u32 id
, anim_apply type
)
153 struct skeleton_bone
*sb
= &skele
->bones
[ id
],
154 *sp
= &skele
->bones
[ sb
->parent
];
156 if( type
== k_anim_apply_defer_ik
)
158 if( (sp
->ik
&& !sb
->ik
) || sp
->defer
)
169 else if( type
== k_anim_apply_deffered_only
)
181 * Apply block of keyframes to skeletons final pose
183 VG_STATIC
void skeleton_apply_pose( struct skeleton
*skele
, mdl_keyframe
*pose
,
184 anim_apply passtype
)
186 m4x3_identity( skele
->final_mtx
[0] );
187 skele
->bones
[0].defer
= 0;
188 skele
->bones
[0].ik
= 0;
190 for( int i
=1; i
<skele
->bone_count
; i
++ )
192 struct skeleton_bone
*sb
= &skele
->bones
[i
],
193 *sp
= &skele
->bones
[ sb
->parent
];
195 if( !should_apply_bone( skele
, i
, passtype
) )
204 v3_sub( skele
->bones
[i
].co
, skele
->bones
[sb
->parent
].co
, temp_delta
);
207 mdl_keyframe
*kf
= &pose
[i
-1];
208 q_m3x3( kf
->q
, posemtx
);
209 v3_copy( kf
->co
, posemtx
[3] );
210 v3_add( temp_delta
, posemtx
[3], posemtx
[3] );
213 m4x3_mul( skele
->final_mtx
[ sb
->parent
], posemtx
, skele
->final_mtx
[i
] );
218 * creates the reference inverse matrix for an IK bone, as it has an initial
219 * intrisic rotation based on the direction that the IK is setup..
221 VG_STATIC
void skeleton_inverse_for_ik( struct skeleton
*skele
,
223 u32 id
, m3x3f inverse
)
225 v3_copy( ivaxis
, inverse
[0] );
226 v3_copy( skele
->bones
[id
].end
, inverse
[1] );
227 v3_normalize( inverse
[1] );
228 v3_cross( inverse
[0], inverse
[1], inverse
[2] );
229 m3x3_transpose( inverse
, inverse
);
233 * Creates inverse rotation matrices which the IK system uses.
235 VG_STATIC
void skeleton_create_inverses( struct skeleton
*skele
)
237 /* IK: inverse 'plane-bone space' axis '(^axis,^bone,...)[base] */
238 for( int i
=0; i
<skele
->ik_count
; i
++ )
240 struct skeleton_ik
*ik
= &skele
->ik
[i
];
243 v3f iv0
, iv1
, ivaxis
;
244 v3_sub( skele
->bones
[ik
->target
].co
, skele
->bones
[ik
->lower
].co
, iv0
);
245 v3_sub( skele
->bones
[ik
->pole
].co
, skele
->bones
[ik
->lower
].co
, iv1
);
246 v3_cross( iv0
, iv1
, ivaxis
);
247 v3_normalize( ivaxis
);
249 skeleton_inverse_for_ik( skele
, ivaxis
, ik
->lower
, ik
->ia
);
250 skeleton_inverse_for_ik( skele
, ivaxis
, ik
->upper
, ik
->ib
);
255 * Apply a model matrix to all bones, should be done last
257 VG_STATIC
void skeleton_apply_transform( struct skeleton
*skele
, m4x3f transform
)
259 for( int i
=0; i
<skele
->bone_count
; i
++ )
261 struct skeleton_bone
*sb
= &skele
->bones
[i
];
262 m4x3_mul( transform
, skele
->final_mtx
[i
], skele
->final_mtx
[i
] );
267 * Apply an inverse matrix to all bones which maps vertices from bind space into
268 * bone relative positions
270 VG_STATIC
void skeleton_apply_inverses( struct skeleton
*skele
)
272 for( int i
=0; i
<skele
->bone_count
; i
++ )
274 struct skeleton_bone
*sb
= &skele
->bones
[i
];
276 m3x3_identity( inverse
);
277 v3_negate( sb
->co
, inverse
[3] );
279 m4x3_mul( skele
->final_mtx
[i
], inverse
, skele
->final_mtx
[i
] );
284 * Apply all IK modifiers (2 bone ik reference from blender is supported)
286 VG_STATIC
void skeleton_apply_ik_pass( struct skeleton
*skele
)
288 for( int 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( int i
=0; i
<skele
->anim_count
; i
++ )
384 struct skeleton_anim
*anim
= &skele
->anims
[i
];
386 if( !strcmp( anim
->name
, name
) )
393 VG_STATIC
void skeleton_alloc_from( struct skeleton
*skele
,
395 struct classtype_skeleton
*inf
)
397 skele
->bone_count
= inf
->channels
;
398 skele
->ik_count
= inf
->ik_count
;
399 skele
->collider_count
= inf
->collider_count
;
400 skele
->anim_count
= inf
->anim_count
;
402 u32 bone_size
= sizeof(struct skeleton_bone
) * skele
->bone_count
,
403 ik_size
= sizeof(struct skeleton_ik
) * skele
->ik_count
,
404 mtx_size
= sizeof(m4x3f
) * skele
->bone_count
,
405 anim_size
= sizeof(struct skeleton_anim
) * skele
->anim_count
;
407 skele
->bones
= vg_linear_alloc( lin_alloc
, bone_size
);
408 skele
->ik
= vg_linear_alloc( lin_alloc
, ik_size
);
409 skele
->final_mtx
= vg_linear_alloc( lin_alloc
, mtx_size
);
410 skele
->anims
= vg_linear_alloc( lin_alloc
, anim_size
);
413 VG_STATIC
void skeleton_fatal_err(void)
415 vg_fatal_exit_loop( "Skeleton setup failed" );
418 /* Setup an animated skeleton from model. mdl's metadata should stick around */
419 VG_STATIC
void skeleton_setup( struct skeleton
*skele
,
420 void *lin_alloc
, mdl_context
*mdl
)
422 u32 bone_count
= 1, skeleton_root
= 0, ik_count
= 0, collider_count
= 0;
423 skele
->bone_count
= 0;
425 skele
->final_mtx
= NULL
;
428 struct classtype_skeleton
*inf
= NULL
;
430 for( u32 i
=0; i
<mdl
->info
.node_count
; i
++ )
432 mdl_node
*pnode
= mdl_node_from_id( mdl
, i
);
434 if( pnode
->classtype
== k_classtype_skeleton
)
436 inf
= mdl_get_entdata( mdl
, pnode
);
437 skeleton_alloc_from( skele
, lin_alloc
, inf
);
440 else if( skele
->bone_count
)
442 int is_bone
= pnode
->classtype
== k_classtype_bone
;
446 if( bone_count
== skele
->bone_count
)
448 vg_error( "too many bones (%u/%u) @%s!\n",
449 bone_count
, skele
->bone_count
,
450 mdl_pstr( mdl
, pnode
->pstr_name
));
452 skeleton_fatal_err();
455 struct skeleton_bone
*sb
= &skele
->bones
[bone_count
];
456 struct classtype_bone
*bone_inf
= mdl_get_entdata( mdl
, pnode
);
457 int is_ik
= bone_inf
->ik_target
;
459 v3_copy( pnode
->co
, sb
->co
);
460 v3_copy( pnode
->s
, sb
->end
);
461 sb
->parent
= pnode
->parent
-skeleton_root
;
462 sb
->name
= mdl_pstr( mdl
, pnode
->pstr_name
);
463 sb
->deform
= bone_inf
->deform
;
467 sb
->ik
= 1; /* TODO: place into new IK array */
468 skele
->bones
[ sb
->parent
].ik
= 1;
470 if( ik_count
== skele
->ik_count
)
472 vg_error( "Too many ik bones, corrupt model file\n" );
473 skeleton_fatal_err();
476 struct skeleton_ik
*ik
= &skele
->ik
[ ik_count
++ ];
477 ik
->upper
= bone_count
;
478 ik
->lower
= sb
->parent
;
479 ik
->target
= bone_inf
->ik_target
;
480 ik
->pole
= bone_inf
->ik_pole
;
487 sb
->collider
= bone_inf
->collider
;
489 box_copy( bone_inf
->hitbox
, sb
->hitbox
);
491 if( bone_inf
->collider
)
493 if( collider_count
== skele
->collider_count
)
495 vg_error( "Too many collider bones\n" );
496 skeleton_fatal_err();
513 vg_error( "No skeleton in model\n" );
514 skeleton_fatal_err();
517 if( collider_count
!= skele
->collider_count
)
519 vg_error( "Loaded %u colliders out of %u\n", collider_count
,
520 skele
->collider_count
);
521 skeleton_fatal_err();
524 if( bone_count
!= skele
->bone_count
)
526 vg_error( "Loaded %u bones out of %u\n", bone_count
, skele
->bone_count
);
527 vg_fatal_exit_loop( "Skeleton setup failed" );
528 skeleton_fatal_err();
531 if( ik_count
!= skele
->ik_count
)
533 vg_error( "Loaded %u ik bones out of %u\n", ik_count
, skele
->ik_count
);
534 skeleton_fatal_err();
537 /* fill in implicit root bone */
538 v3_zero( skele
->bones
[0].co
);
539 v3_copy( (v3f
){0.0f
,1.0f
,0.0f
}, skele
->bones
[0].end
);
540 skele
->bones
[0].parent
= 0xffffffff;
541 skele
->bones
[0].collider
= 0;
542 skele
->bones
[0].name
= "[root]";
544 /* process animation quick refs */
545 for( int i
=0; i
<skele
->anim_count
; i
++ )
547 mdl_animation
*anim
= &mdl
->anim_buffer
[ inf
->anim_start
+ i
];
549 skele
->anims
[i
].rate
= anim
->rate
;
550 skele
->anims
[i
].length
= anim
->length
;
551 skele
->anims
[i
].name
= mdl_pstr(mdl
, anim
->pstr_name
);
552 skele
->anims
[i
].anim_data
= &mdl
->keyframe_buffer
[ anim
->offset
];
554 vg_info( "animation[ %f, %u ] '%s'\n", anim
->rate
,
556 skele
->anims
[i
].name
);
559 skeleton_create_inverses( skele
);
560 vg_success( "Loaded skeleton with %u bones\n", skele
->bone_count
);
561 vg_success( " %u colliders\n", skele
->collider_count
);
564 VG_STATIC
void skeleton_debug( struct skeleton
*skele
)
566 for( int i
=0; i
<skele
->bone_count
; i
++ )
568 struct skeleton_bone
*sb
= &skele
->bones
[i
];
571 v3_copy( sb
->co
, p0
);
572 v3_add( p0
, sb
->end
, p1
);
573 //vg_line( p0, p1, 0xffffffff );
575 m4x3_mulv( skele
->final_mtx
[i
], p0
, p0
);
576 m4x3_mulv( skele
->final_mtx
[i
], p1
, p1
);
582 vg_line( p0
, p1
, 0xff0000ff );
586 vg_line( p0
, p1
, 0xffcccccc );
590 vg_line( p0
, p1
, 0xff00ffff );
594 #endif /* SKELETON_H */