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Differential D11057 Diff 36451 source/blender/blenkernel/intern/armature_update.c

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source/blender/blenkernel/intern/armature_update.c

Show First 20 Lines • Show All 57 Lines • ▼ Show 20 Linestypedef struct tSplineIK_Tree {
short chainlen; /* number of bones in the chain */ short chainlen; /* number of bones in the chain */
float totlength; /* total length of bones in the chain */ float totlength; /* total length of bones in the chain */
const float *points; /* parametric positions for the joints along the curve */ const float *points; /* parametric positions for the joints along the curve */
bPoseChannel **chain; /* chain of bones to affect using Spline IK (ordered from the tip) */ bPoseChannel **chain; /* chain of bones to affect using Spline IK (ordered from the tip) */
bPoseChannel *root; /* bone that is the root node of the chain */ bPoseChannel *root; /* bone that is the root node of the chain */
bConstraint *con; /* constraint for this chain */ bConstraint *con; /* constraint for this chain */
bSplineIKConstraint *ikData; /* constraint settings for this chain */ bSplineIKConstraint *ik_data; /* constraint settings for this chain */
} tSplineIK_Tree; } tSplineIK_Tree;
/* ----------- */ /* ----------- */
/* Tag the bones in the chain formed by the given bone for IK */ /* Tag the bones in the chain formed by the given bone for IK. */
static void splineik_init_tree_from_pchan(Scene *UNUSED(scene), static void splineik_init_tree_from_pchan(Scene *UNUSED(scene),
Object *UNUSED(ob), Object *UNUSED(ob),
bPoseChannel *pchan_tip) bPoseChannel *pchan_tip)
{ {
bPoseChannel *pchan, *pchanRoot = NULL; bPoseChannel *pchan, *pchan_root = NULL;
bPoseChannel *pchanChain[255]; bPoseChannel *pchan_chain[255];
bConstraint *con = NULL; bConstraint *con = NULL;
bSplineIKConstraint *ikData = NULL; bSplineIKConstraint *ik_data = NULL;
float boneLengths[255]; float bone_lengths[255];
float totLength = 0.0f; float totlength = 0.0f;
int segcount = 0; int segcount = 0;
/* find the SplineIK constraint */ /* Find the SplineIK constraint. */
for (con = pchan_tip->constraints.first; con; con = con->next) { for (con = pchan_tip->constraints.first; con; con = con->next) {
if (con->type == CONSTRAINT_TYPE_SPLINEIK) { if (con->type == CONSTRAINT_TYPE_SPLINEIK) {
ikData = con->data; ik_data = con->data;
/* target can only be curve */ /* Target can only be a curve. */
if ((ikData->tar == NULL) || (ikData->tar->type != OB_CURVE)) { if ((ik_data->tar == NULL) || (ik_data->tar->type != OB_CURVE)) {
continue; continue;
} }
/* skip if disabled */ /* Skip if disabled. */
if ((con->enforce == 0.0f) || (con->flag & (CONSTRAINT_DISABLE | CONSTRAINT_OFF))) { if ((con->enforce == 0.0f) || (con->flag & (CONSTRAINT_DISABLE | CONSTRAINT_OFF))) {
continue; continue;
} }
/* otherwise, constraint is ok... */ /* Otherwise, constraint is ok... */
break; break;
} }
} }
if (con == NULL) { if (con == NULL) {
return; return;
} }
/* find the root bone and the chain of bones from the root to the tip /* Find the root bone and the chain of bones from the root to the tip.
* NOTE: this assumes that the bones are connected, but that may not be true... */ * NOTE: this assumes that the bones are connected, but that may not be true... */
for (pchan = pchan_tip; pchan && (segcount < ikData->chainlen); for (pchan = pchan_tip; pchan && (segcount < ik_data->chainlen);
pchan = pchan->parent, segcount++) { pchan = pchan->parent, segcount++) {
/* store this segment in the chain */ /* Store this segment in the chain. */
pchanChain[segcount] = pchan; pchan_chain[segcount] = pchan;
/* if performing rebinding, calculate the length of the bone */ /* If performing rebinding, calculate the length of the bone. */
boneLengths[segcount] = pchan->bone->length; bone_lengths[segcount] = pchan->bone->length;
totLength += boneLengths[segcount]; totlength += bone_lengths[segcount];
} }
if (segcount == 0) { if (segcount == 0) {
return; return;
} }
pchanRoot = pchanChain[segcount - 1]; pchan_root = pchan_chain[segcount - 1];
/* perform binding step if required */ /* Perform binding step if required. */
if ((ikData->flag & CONSTRAINT_SPLINEIK_BOUND) == 0) { if ((ik_data->flag & CONSTRAINT_SPLINEIK_BOUND) == 0) {
float segmentLen = (1.0f / (float)segcount); float segmentLen = (1.0f / (float)segcount);
/* setup new empty array for the points list */ /* Setup new empty array for the points list. */
if (ikData->points) { if (ik_data->points) {
MEM_freeN(ikData->points); MEM_freeN(ik_data->points);
} }
ikData->numpoints = ikData->chainlen + 1; ik_data->numpoints = ik_data->chainlen + 1;
ikData->points = MEM_mallocN(sizeof(float) * ikData->numpoints, "Spline IK Binding"); ik_data->points = MEM_mallocN(sizeof(float) * ik_data->numpoints, "Spline IK Binding");
/* bind 'tip' of chain (i.e. first joint = tip of bone with the Spline IK Constraint) */ /* Bind 'tip' of chain (i.e. first joint = tip of bone with the Spline IK Constraint). */
ikData->points[0] = 1.0f; ik_data->points[0] = 1.0f;
/* perform binding of the joints to parametric positions along the curve based /* Perform binding of the joints to parametric positions along the curve based
* proportion of the total length that each bone occupies * proportion of the total length that each bone occupies.
*/ */
for (int i = 0; i < segcount; i++) { for (int i = 0; i < segcount; i++) {
/* 'head' joints, traveling towards the root of the chain /* 'head' joints, traveling towards the root of the chain.
* - 2 methods; the one chosen depends on whether we've got usable lengths * - 2 methods; the one chosen depends on whether we've got usable lengths.
*/ */
if ((ikData->flag & CONSTRAINT_SPLINEIK_EVENSPLITS) || (totLength == 0.0f)) { if ((ik_data->flag & CONSTRAINT_SPLINEIK_EVENSPLITS) || (totlength == 0.0f)) {
/* 1) equi-spaced joints */ /* 1) Equi-spaced joints. */
ikData->points[i + 1] = ikData->points[i] - segmentLen; ik_data->points[i + 1] = ik_data->points[i] - segmentLen;
} }
else { else {
/* 2) to find this point on the curve, we take a step from the previous joint /* 2) To find this point on the curve, we take a step from the previous joint
* a distance given by the proportion that this bone takes * a distance given by the proportion that this bone takes.
*/ */
ikData->points[i + 1] = ikData->points[i] - (boneLengths[i] / totLength); ik_data->points[i + 1] = ik_data->points[i] - (bone_lengths[i] / totlength);
} }
} }
/* spline has now been bound */ /* Spline has now been bound. */
ikData->flag |= CONSTRAINT_SPLINEIK_BOUND; ik_data->flag |= CONSTRAINT_SPLINEIK_BOUND;
} }
/* disallow negative values (happens with float precision) */ /* Disallow negative values (happens with float precision). */
CLAMP_MIN(ikData->points[segcount], 0.0f); CLAMP_MIN(ik_data->points[segcount], 0.0f);
/* make a new Spline-IK chain, and store it in the IK chains */ /* Make a new Spline-IK chain, and store it in the IK chains. */
/* TODO: we should check if there is already an IK chain on this, /* TODO: we should check if there is already an IK chain on this,
* since that would take precedence... */ * since that would take precedence... */
{ {
/* make new tree */ /* Make a new tree. */
tSplineIK_Tree *tree = MEM_callocN(sizeof(tSplineIK_Tree), "SplineIK Tree"); tSplineIK_Tree *tree = MEM_callocN(sizeof(tSplineIK_Tree), "SplineIK Tree");
tree->type = CONSTRAINT_TYPE_SPLINEIK; tree->type = CONSTRAINT_TYPE_SPLINEIK;
tree->chainlen = segcount; tree->chainlen = segcount;
tree->totlength = totLength; tree->totlength = totlength;
/* copy over the array of links to bones in the chain (from tip to root) */ /* Copy over the array of links to bones in the chain (from tip to root). */
tree->chain = MEM_mallocN(sizeof(bPoseChannel *) * segcount, "SplineIK Chain"); tree->chain = MEM_mallocN(sizeof(bPoseChannel *) * segcount, "SplineIK Chain");
memcpy(tree->chain, pchanChain, sizeof(bPoseChannel *) * segcount); memcpy(tree->chain, pchan_chain, sizeof(bPoseChannel *) * segcount);
/* store reference to joint position array */ /* Store reference to joint position array. */
tree->points = ikData->points; tree->points = ik_data->points;
/* store references to different parts of the chain */ /* Store references to different parts of the chain. */
tree->root = pchanRoot; tree->root = pchan_root;
tree->con = con; tree->con = con;
tree->ikData = ikData; tree->ik_data = ik_data;
/* AND! link the tree to the root */ /* AND! Link the tree to the root. */
BLI_addtail(&pchanRoot->siktree, tree); BLI_addtail(&pchan_root->siktree, tree);
} }
/* mark root channel having an IK tree */ /* Mark root channel having an IK tree. */
pchanRoot->flag |= POSE_IKSPLINE; pchan_root->flag |= POSE_IKSPLINE;
} }
/* Tag which bones are members of Spline IK chains */ /* Tag which bones are members of Spline IK chains. */
static void splineik_init_tree(Scene *scene, Object *ob, float UNUSED(ctime)) static void splineik_init_tree(Scene *scene, Object *ob, float UNUSED(ctime))
{ {
bPoseChannel *pchan; bPoseChannel *pchan;
/* find the tips of Spline IK chains, /* Find the tips of Spline IK chains,
* which are simply the bones which have been tagged as such */ * which are simply the bones which have been tagged as such. */
for (pchan = ob->pose->chanbase.first; pchan; pchan = pchan->next) { for (pchan = ob->pose->chanbase.first; pchan; pchan = pchan->next) {
if (pchan->constflag & PCHAN_HAS_SPLINEIK) { if (pchan->constflag & PCHAN_HAS_SPLINEIK) {
splineik_init_tree_from_pchan(scene, ob, pchan); splineik_init_tree_from_pchan(scene, ob, pchan);
} }
} }
} }
/* ----------- */ /* ----------- */
typedef struct tSplineIk_EvalState { typedef struct tSplineIk_EvalState {
float curve_position; /* Current position along the curve. */ float curve_position; /* Current position along the curve. */
float curve_scale; /* Global scale to apply to curve positions. */ float curve_scale; /* Global scale to apply to curve positions. */
float locrot_offset[4][4]; /* Bone rotation and location offset inherited from parent. */ float locrot_offset[4][4]; /* Bone rotation and location offset inherited from parent. */
float prev_tail_loc[3]; /* Tail location of the previous bone. */
float prev_tail_radius; /* Tail curve radius of the previous bone. */
int prev_tail_seg_idx; /* Curve segment the previous tail bone belongs to. */
} tSplineIk_EvalState; } tSplineIk_EvalState;
/* Prepare data to evaluate spline IK. */ /* Prepare data to evaluate spline IK. */
static bool splineik_evaluate_init(tSplineIK_Tree *tree, tSplineIk_EvalState *state) static bool splineik_evaluate_init(tSplineIK_Tree *tree, tSplineIk_EvalState *state)
{ {
bSplineIKConstraint *ikData = tree->ikData; bSplineIKConstraint *ik_data = tree->ik_data;
/* Make sure that the constraint targets are ok, to avoid crashes /* Make sure that the constraint targets are ok, to avoid crashes
* in case of a depsgraph bug or dependency cycle. * in case of a depsgraph bug or dependency cycle.
*/ */
if (ikData->tar == NULL) { if (ik_data->tar == NULL) {
return false; return false;
} }
CurveCache *cache = ikData->tar->runtime.curve_cache; CurveCache *cache = ik_data->tar->runtime.curve_cache;
if (ELEM(NULL, cache, cache->path, cache->path->data)) { if (ELEM(NULL, cache, cache->anim_path_accum_length)) {
return false; return false;
} }
/* Initialize the evaluation state. */ /* Initialize the evaluation state. */
state->curve_position = 0.0f; state->curve_position = 0.0f;
state->curve_scale = 1.0f; state->curve_scale = 1.0f;
unit_m4(state->locrot_offset); unit_m4(state->locrot_offset);
zero_v3(state->prev_tail_loc);
state->prev_tail_radius = 1.0f;
state->prev_tail_seg_idx = 0;
/* Apply corrections for sensitivity to scaling. */ /* Apply corrections for sensitivity to scaling. */
if ((ikData->yScaleMode != CONSTRAINT_SPLINEIK_YS_FIT_CURVE) && (tree->totlength != 0.0f)) { if ((ik_data->yScaleMode != CONSTRAINT_SPLINEIK_YS_FIT_CURVE) && (tree->totlength != 0.0f)) {
/* get the current length of the curve */ /* Get the current length of the curve. */
/* NOTE: this is assumed to be correct even after the curve was resized */ /* NOTE: This is assumed to be correct even after the curve was resized. */
float splineLen = cache->path->totdist; const float spline_len = BKE_anim_path_get_length(cache);
/* calculate the scale factor to multiply all the path values by so that the /* Calculate the scale factor to multiply all the path values by so that the
* bone chain retains its current length, such that * bone chain retains its current length, such that:
* maxScale * splineLen = totLength * maxScale * splineLen = totLength
*/ */
state->curve_scale = tree->totlength / splineLen; state->curve_scale = tree->totlength / spline_len;
} }
return true; return true;
} }
static void apply_curve_transform(
bSplineIKConstraint *ik_data, Object *ob, float radius, float r_vec[3], float *r_radius)
{
/* Apply the curve's object-mode transforms to the position
* unless the option to allow curve to be positioned elsewhere is activated (i.e. no root).
*/
if ((ik_data->flag & CONSTRAINT_SPLINEIK_NO_ROOT) == 0) {
mul_m4_v3(ik_data->tar->obmat, r_vec);
}
/* Convert the position to pose-space. */
mul_m4_v3(ob->imat, r_vec);
/* Set the new radius (it should be the average value). */
*r_radius = (radius + *r_radius) / 2;
}
/* This function positions the tail of the bone so that it preserves the length of it.
* The length of the bone can be seen as a sphere radius.
*/
static int position_tail_on_spline(bSplineIKConstraint *ik_data,
const float head_pos[3],
const float sphere_radius,
const int prev_seg_idx,
float r_tail_pos[3],
float *r_new_curve_pos,
float *r_radius)
{
/* This is using the tessellated curve data.
* So we are working with piece-wise linear curve segments.
* The same method is use in #BKE_where_on_path to get curve location data. */
const CurveCache *cache = ik_data->tar->runtime.curve_cache;
const BevList *bl = cache->bev.first;
BevPoint *bp = bl->bevpoints;
const float spline_len = BKE_anim_path_get_length(cache);
const float *seg_accum_len = cache->anim_path_accum_length;
int max_seg_idx = BKE_anim_path_get_array_size(cache) - 1;
/* Convert our initial intersection point guess to a point index.
* If the curve was a straight line, then pointEnd would be the correct location.
* So make it our first initial guess.
*/
const float guessed_len = *r_new_curve_pos * spline_len;
BLI_assert(prev_seg_idx >= 0);
int cur_seg_idx = prev_seg_idx;
while (cur_seg_idx < max_seg_idx && guessed_len > seg_accum_len[cur_seg_idx]) {
cur_seg_idx++;
}
int bp_idx = cur_seg_idx + 1;
bp = bp + bp_idx;
bool is_cyclic = bl->poly >= 0;
BevPoint *prev_bp = bp - 1;
/* Go to the next tessellated curve point until we cross to outside of the sphere. */
while (len_v3v3(head_pos, bp->vec) < sphere_radius) {
if (bp_idx > max_seg_idx) {
/* We are outside the defined curve. We will now extrapolate the intersection point. */
break;
}
prev_bp = bp;
if (is_cyclic && bp_idx == max_seg_idx) {
/* Wrap around to the start point.
* Don't set the bp_idx to zero here as we use it to get the segment index later.
*/
bp = bl->bevpoints;
}
else {
bp++;
}
bp_idx++;
}
float isect_1[3], isect_2[3];
/* Calculate the intersection point. */
isect_line_sphere_v3(prev_bp->vec, bp->vec, head_pos, sphere_radius, isect_1, isect_2);
/* Because of how `isect_line_sphere_v3` works, we know that `isect_1` contains the
* intersection point we want. And it will always intersect as we go from inside to outside
* of the sphere.
*/
copy_v3_v3(r_tail_pos, isect_1);
cur_seg_idx = bp_idx - 2;
float prev_seg_len = 0;
if (cur_seg_idx < 0) {
cur_seg_idx = 0;
prev_seg_len = 0;
}
else {
prev_seg_len = seg_accum_len[cur_seg_idx];
}
/* Convert the point back into the 0-1 interpolation range. */
const float isect_seg_len = len_v3v3(prev_bp->vec, isect_1);
const float frac = isect_seg_len / len_v3v3(prev_bp->vec, bp->vec);
*r_new_curve_pos = (prev_seg_len + isect_seg_len) / spline_len;
if (*r_new_curve_pos > 1.0f) {
*r_radius = bp->radius;
}
else {
*r_radius = (1.0f - frac) * prev_bp->radius + frac * bp->radius;
}
return cur_seg_idx;
}
/* Evaluate spline IK for a given bone. */ /* Evaluate spline IK for a given bone. */
static void splineik_evaluate_bone( static void splineik_evaluate_bone(
tSplineIK_Tree *tree, Object *ob, bPoseChannel *pchan, int index, tSplineIk_EvalState *state) tSplineIK_Tree *tree, Object *ob, bPoseChannel *pchan, int index, tSplineIk_EvalState *state)
{ {
bSplineIKConstraint *ikData = tree->ikData; bSplineIKConstraint *ik_data = tree->ik_data;
float origHead[3], origTail[3], poseHead[3], poseTail[3], basePoseMat[3][3], poseMat[3][3];
float splineVec[3], scaleFac, radius = 1.0f; if (pchan->bone->length == 0.0f) {
float tailBlendFac = 0.0f; /* Only move the bone position with zero length bones. */
float bone_pos[4], dir[3], rad;
BKE_where_on_path(ik_data->tar, state->curve_position, bone_pos, dir, NULL, &rad, NULL);
apply_curve_transform(ik_data, ob, rad, bone_pos, &rad);
copy_v3_v3(pchan->pose_mat[3], bone_pos);
copy_v3_v3(pchan->pose_head, bone_pos);
copy_v3_v3(pchan->pose_tail, bone_pos);
pchan->flag |= POSE_DONE;
return;
}
mul_v3_m4v3(poseHead, state->locrot_offset, pchan->pose_head); float orig_head[3], orig_tail[3], pose_head[3], pose_tail[3];
mul_v3_m4v3(poseTail, state->locrot_offset, pchan->pose_tail); float base_pose_mat[3][3], pose_mat[3][3];
float spline_vec[3], scale_fac, radius = 1.0f;
float tail_blend_fac = 0.0f;
copy_v3_v3(origHead, poseHead); mul_v3_m4v3(pose_head, state->locrot_offset, pchan->pose_head);
mul_v3_m4v3(pose_tail, state->locrot_offset, pchan->pose_tail);
/* first, adjust the point positions on the curve */ copy_v3_v3(orig_head, pose_head);
/* First, adjust the point positions on the curve. */
float curveLen = tree->points[index] - tree->points[index + 1]; float curveLen = tree->points[index] - tree->points[index + 1];
float pointStart = state->curve_position; float bone_len = len_v3v3(pose_head, pose_tail);
float poseScale = len_v3v3(poseHead, poseTail) / pchan->bone->length; float point_start = state->curve_position;
float baseScale = 1.0f; float pose_scale = bone_len / pchan->bone->length;
float base_scale = 1.0f;
if (ikData->yScaleMode == CONSTRAINT_SPLINEIK_YS_ORIGINAL) { if (ik_data->yScaleMode == CONSTRAINT_SPLINEIK_YS_ORIGINAL) {
/* Carry over the bone Y scale to the curve range. */ /* Carry over the bone Y scale to the curve range. */
baseScale = poseScale; base_scale = pose_scale;
} }
float pointEnd = pointStart + curveLen * baseScale * state->curve_scale; float point_end = point_start + curveLen * base_scale * state->curve_scale;
state->curve_position = pointEnd; state->curve_position = point_end;
/* step 1: determine the positions for the endpoints of the bone */ /* Step 1: determine the positions for the endpoints of the bone. */
if (pointStart < 1.0f) { if (point_start < 1.0f) {
float vec[4], dir[3], rad; float vec[4], dir[3], rad;
radius = 0.0f;
/* determine if the bone should still be affected by SplineIK */ /* Calculate head position. */
if (pointEnd >= 1.0f) { if (point_start == 0.0f) {
/* blending factor depends on the amount of the bone still left on the chain */ /* Start of the path. We have no previous tail position to copy. */
tailBlendFac = (1.0f - pointStart) / (pointEnd - pointStart); BKE_where_on_path(ik_data->tar, point_start, vec, dir, NULL, &rad, NULL);
} }
else { else {
tailBlendFac = 1.0f; copy_v3_v3(vec, state->prev_tail_loc);
rad = state->prev_tail_radius;
} }
/* tail endpoint */ radius = rad;
if (where_on_path(ikData->tar, pointEnd, vec, dir, NULL, &rad, NULL)) { copy_v3_v3(pose_head, vec);
/* apply curve's object-mode transforms to the position apply_curve_transform(ik_data, ob, rad, pose_head, &radius);
* unless the option to allow curve to be positioned elsewhere is activated (i.e. no root)
*/
if ((ikData->flag & CONSTRAINT_SPLINEIK_NO_ROOT) == 0) {
mul_m4_v3(ikData->tar->obmat, vec);
}
/* convert the position to pose-space, then store it */ /* Calculate tail position. */
mul_m4_v3(ob->imat, vec); if (ik_data->yScaleMode != CONSTRAINT_SPLINEIK_YS_FIT_CURVE) {
copy_v3_v3(poseTail, vec); float sphere_radius;
/* set the new radius */ if (ik_data->yScaleMode == CONSTRAINT_SPLINEIK_YS_ORIGINAL) {
radius = rad; sphere_radius = bone_len;
} }
else {
/* head endpoint */ /* Don't take bone scale into account. */
if (where_on_path(ikData->tar, pointStart, vec, dir, NULL, &rad, NULL)) { sphere_radius = pchan->bone->length;
/* apply curve's object-mode transforms to the position
* unless the option to allow curve to be positioned elsewhere is activated (i.e. no root)
*/
if ((ikData->flag & CONSTRAINT_SPLINEIK_NO_ROOT) == 0) {
mul_m4_v3(ikData->tar->obmat, vec);
} }
/* store the position, and convert it to pose space */ /* Calculate the tail position with sphere curve intersection. */
mul_m4_v3(ob->imat, vec); state->prev_tail_seg_idx = position_tail_on_spline(
copy_v3_v3(poseHead, vec); ik_data, vec, sphere_radius, state->prev_tail_seg_idx, pose_tail, &point_end, &rad);
/* set the new radius (it should be the average value) */ state->prev_tail_radius = rad;
radius = (radius + rad) / 2; copy_v3_v3(state->prev_tail_loc, pose_tail);
apply_curve_transform(ik_data, ob, rad, pose_tail, &radius);
state->curve_position = point_end;
}
else {
/* Scale to fit curve end position. */
if (BKE_where_on_path(ik_data->tar, point_end, vec, dir, NULL, &rad, NULL)) {
state->prev_tail_radius = rad;
copy_v3_v3(state->prev_tail_loc, vec);
copy_v3_v3(pose_tail, vec);
apply_curve_transform(ik_data, ob, rad, pose_tail, &radius);
}
}
/* Determine if the bone should still be affected by SplineIK.
* This makes it so that the bone slowly becomes poseable again the further it rolls off the
* curve. When the whole bone has rolled off the curve, the IK constraint will not influence it
* anymore.
*/
if (point_end >= 1.0f) {
/* Blending factor depends on the amount of the bone still left on the chain. */
tail_blend_fac = (1.0f - point_start) / (point_end - point_start);
}
else {
tail_blend_fac = 1.0f;
} }
} }
/* Step 2: determine the implied transform from these endpoints. /* Step 2: determine the implied transform from these endpoints.
* - splineVec: the vector direction that the spline applies on the bone. * - splineVec: the vector direction that the spline applies on the bone.
* - scaleFac: the factor that the bone length is scaled by to get the desired amount. * - scaleFac: the factor that the bone length is scaled by to get the desired amount.
*/ */
sub_v3_v3v3(splineVec, poseTail, poseHead); sub_v3_v3v3(spline_vec, pose_tail, pose_head);
scaleFac = len_v3(splineVec) / pchan->bone->length; scale_fac = len_v3(spline_vec) / pchan->bone->length;
/* Extrapolate the full length of the bone as it rolls off the end of the curve. */
scaleFac = (tailBlendFac < 1e-5f) ? baseScale : scaleFac / tailBlendFac;
/* Step 3: compute the shortest rotation needed /* Step 3: compute the shortest rotation needed
* to map from the bone rotation to the current axis. * to map from the bone rotation to the current axis.
* - this uses the same method as is used for the Damped Track Constraint * - this uses the same method as is used for the Damped Track Constraint
* (see the code there for details). * (see the code there for details).
*/ */
{ {
float dmat[3][3], rmat[3][3]; float dmat[3][3], rmat[3][3];
float raxis[3], rangle; float raxis[3], rangle;
/* compute the raw rotation matrix from the bone's current matrix by extracting only the /* Compute the raw rotation matrix from the bone's current matrix by extracting only the
* orientation-relevant axes, and normalizing them * orientation-relevant axes, and normalizing them.
*/ */
mul_m3_m4m4(basePoseMat, state->locrot_offset, pchan->pose_mat); mul_m3_m4m4(base_pose_mat, state->locrot_offset, pchan->pose_mat);
normalize_m3_m3(rmat, basePoseMat); normalize_m3_m3(rmat, base_pose_mat);
/* Also, normalize the orientation imposed by the bone, /* Also, normalize the orientation imposed by the bone,
* now that we've extracted the scale factor. */ * now that we've extracted the scale factor. */
normalize_v3(splineVec); normalize_v3(spline_vec);
/* calculate smallest axis-angle rotation necessary for getting from the /* Calculate smallest axis-angle rotation necessary for getting from the
* current orientation of the bone, to the spline-imposed direction * current orientation of the bone, to the spline-imposed direction.
*/ */
cross_v3_v3v3(raxis, rmat[1], splineVec); cross_v3_v3v3(raxis, rmat[1], spline_vec);
rangle = dot_v3v3(rmat[1], splineVec); rangle = dot_v3v3(rmat[1], spline_vec);
CLAMP(rangle, -1.0f, 1.0f); CLAMP(rangle, -1.0f, 1.0f);
rangle = acosf(rangle); rangle = acosf(rangle);
/* multiply the magnitude of the angle by the influence of the constraint to /* Multiply the magnitude of the angle by the influence of the constraint to
* control the influence of the SplineIK effect * control the influence of the SplineIK effect.
*/ */
rangle *= tree->con->enforce * tailBlendFac; rangle *= tree->con->enforce * tail_blend_fac;
/* construct rotation matrix from the axis-angle rotation found above /* Construct rotation matrix from the axis-angle rotation found above.
* - this call takes care to make sure that the axis provided is a unit vector first * - This call takes care to make sure that the axis provided is a unit vector first.
*/ */
axis_angle_to_mat3(dmat, raxis, rangle); axis_angle_to_mat3(dmat, raxis, rangle);
/* Combine these rotations so that the y-axis of the bone is now aligned as the /* Combine these rotations so that the y-axis of the bone is now aligned as the
* spline dictates, while still maintaining roll control from the existing bone animation. */ * spline dictates, while still maintaining roll control from the existing bone animation. */
mul_m3_m3m3(poseMat, dmat, rmat); mul_m3_m3m3(pose_mat, dmat, rmat);
/* attempt to reduce shearing, though I doubt this'll really help too much now... */ /* Attempt to reduce shearing, though I doubt this'll really help too much now... */
normalize_m3(poseMat); normalize_m3(pose_mat);
mul_m3_m3m3(basePoseMat, dmat, basePoseMat); mul_m3_m3m3(base_pose_mat, dmat, base_pose_mat);
/* apply rotation to the accumulated parent transform */ /* Apply rotation to the accumulated parent transform. */
mul_m4_m3m4(state->locrot_offset, dmat, state->locrot_offset); mul_m4_m3m4(state->locrot_offset, dmat, state->locrot_offset);
} }
/* step 4: set the scaling factors for the axes */ /* Step 4: Set the scaling factors for the axes. */
/* Always multiply the y-axis by the scaling factor to get the correct length. */ /* Always multiply the y-axis by the scaling factor to get the correct length. */
mul_v3_fl(poseMat[1], scaleFac); mul_v3_fl(pose_mat[1], scale_fac);
/* After that, apply x/z scaling modes. */ /* After that, apply x/z scaling modes. */
if (ikData->xzScaleMode != CONSTRAINT_SPLINEIK_XZS_NONE) { if (ik_data->xzScaleMode != CONSTRAINT_SPLINEIK_XZS_NONE) {
/* First, apply the original scale if enabled. */ /* First, apply the original scale if enabled. */
if (ikData->xzScaleMode == CONSTRAINT_SPLINEIK_XZS_ORIGINAL || if (ik_data->xzScaleMode == CONSTRAINT_SPLINEIK_XZS_ORIGINAL ||
(ikData->flag & CONSTRAINT_SPLINEIK_USE_ORIGINAL_SCALE) != 0) { (ik_data->flag & CONSTRAINT_SPLINEIK_USE_ORIGINAL_SCALE) != 0) {
float scale; float scale;
/* x-axis scale */ /* X-axis scale. */
scale = len_v3(pchan->pose_mat[0]); scale = len_v3(pchan->pose_mat[0]);
mul_v3_fl(poseMat[0], scale); mul_v3_fl(pose_mat[0], scale);
/* z-axis scale */ /* Z-axis scale. */
scale = len_v3(pchan->pose_mat[2]); scale = len_v3(pchan->pose_mat[2]);
mul_v3_fl(poseMat[2], scale); mul_v3_fl(pose_mat[2], scale);
/* Adjust the scale factor used for volume preservation /* Adjust the scale factor used for volume preservation
* to consider the pre-IK scaling as the initial volume. */ * to consider the pre-IK scaling as the initial volume. */
scaleFac /= poseScale; scale_fac /= pose_scale;
} }
/* Apply volume preservation. */ /* Apply volume preservation. */
switch (ikData->xzScaleMode) { switch (ik_data->xzScaleMode) {
case CONSTRAINT_SPLINEIK_XZS_INVERSE: { case CONSTRAINT_SPLINEIK_XZS_INVERSE: {
/* old 'volume preservation' method using the inverse scale */ /* Old 'volume preservation' method using the inverse scale. */
float scale; float scale;
/* calculate volume preservation factor which is /* Calculate volume preservation factor which is
* basically the inverse of the y-scaling factor * basically the inverse of the y-scaling factor.
*/ */
if (fabsf(scaleFac) != 0.0f) { if (fabsf(scale_fac) != 0.0f) {
scale = 1.0f / fabsf(scaleFac); scale = 1.0f / fabsf(scale_fac);
/* We need to clamp this within sensible values. */ /* We need to clamp this within sensible values. */
/* NOTE: these should be fine for now, but should get sanitized in future. */ /* NOTE: these should be fine for now, but should get sanitized in future. */
CLAMP(scale, 0.0001f, 100000.0f); CLAMP(scale, 0.0001f, 100000.0f);
} }
else { else {
scale = 1.0f; scale = 1.0f;
} }
/* apply the scaling */ /* Apply the scaling. */
mul_v3_fl(poseMat[0], scale); mul_v3_fl(pose_mat[0], scale);
mul_v3_fl(poseMat[2], scale); mul_v3_fl(pose_mat[2], scale);
break; break;
} }
case CONSTRAINT_SPLINEIK_XZS_VOLUMETRIC: { case CONSTRAINT_SPLINEIK_XZS_VOLUMETRIC: {
/* improved volume preservation based on the Stretch To constraint */ /* Improved volume preservation based on the Stretch To constraint. */
float final_scale; float final_scale;
/* as the basis for volume preservation, we use the inverse scale factor... */ /* As the basis for volume preservation, we use the inverse scale factor... */
if (fabsf(scaleFac) != 0.0f) { if (fabsf(scale_fac) != 0.0f) {
/* NOTE: The method here is taken wholesale from the Stretch To constraint */ /* NOTE: The method here is taken wholesale from the Stretch To constraint. */
float bulge = powf(1.0f / fabsf(scaleFac), ikData->bulge); float bulge = powf(1.0f / fabsf(scale_fac), ik_data->bulge);
if (bulge > 1.0f) { if (bulge > 1.0f) {
if (ikData->flag & CONSTRAINT_SPLINEIK_USE_BULGE_MAX) { if (ik_data->flag & CONSTRAINT_SPLINEIK_USE_BULGE_MAX) {
float bulge_max = max_ff(ikData->bulge_max, 1.0f); float bulge_max = max_ff(ik_data->bulge_max, 1.0f);
float hard = min_ff(bulge, bulge_max); float hard = min_ff(bulge, bulge_max);
float range = bulge_max - 1.0f; float range = bulge_max - 1.0f;
float scale = (range > 0.0f) ? 1.0f / range : 0.0f; float scale = (range > 0.0f) ? 1.0f / range : 0.0f;
float soft = 1.0f + range * atanf((bulge - 1.0f) * scale) / (float)M_PI_2; float soft = 1.0f + range * atanf((bulge - 1.0f) * scale) / (float)M_PI_2;
bulge = interpf(soft, hard, ikData->bulge_smooth); bulge = interpf(soft, hard, ik_data->bulge_smooth);
} }
} }
if (bulge < 1.0f) { if (bulge < 1.0f) {
if (ikData->flag & CONSTRAINT_SPLINEIK_USE_BULGE_MIN) { if (ik_data->flag & CONSTRAINT_SPLINEIK_USE_BULGE_MIN) {
float bulge_min = CLAMPIS(ikData->bulge_min, 0.0f, 1.0f); float bulge_min = CLAMPIS(ik_data->bulge_min, 0.0f, 1.0f);
float hard = max_ff(bulge, bulge_min); float hard = max_ff(bulge, bulge_min);
float range = 1.0f - bulge_min; float range = 1.0f - bulge_min;
float scale = (range > 0.0f) ? 1.0f / range : 0.0f; float scale = (range > 0.0f) ? 1.0f / range : 0.0f;
float soft = 1.0f - range * atanf((1.0f - bulge) * scale) / (float)M_PI_2; float soft = 1.0f - range * atanf((1.0f - bulge) * scale) / (float)M_PI_2;
bulge = interpf(soft, hard, ikData->bulge_smooth); bulge = interpf(soft, hard, ik_data->bulge_smooth);
} }
} }
/* compute scale factor for xz axes from this value */ /* Compute scale factor for xz axes from this value. */
final_scale = sqrtf(bulge); final_scale = sqrtf(bulge);
} }
else { else {
/* no scaling, so scale factor is simple */ /* No scaling, so scale factor is simple. */
final_scale = 1.0f; final_scale = 1.0f;
} }
/* Apply the scaling (assuming normalized scale). */ /* Apply the scaling (assuming normalized scale). */
mul_v3_fl(poseMat[0], final_scale); mul_v3_fl(pose_mat[0], final_scale);
mul_v3_fl(poseMat[2], final_scale); mul_v3_fl(pose_mat[2], final_scale);
break; break;
} }
} }
} }
/* Finally, multiply the x and z scaling by the radius of the curve too, /* Finally, multiply the x and z scaling by the radius of the curve too,
* to allow automatic scales to get tweaked still. * to allow automatic scales to get tweaked still.
*/ */
if ((ikData->flag & CONSTRAINT_SPLINEIK_NO_CURVERAD) == 0) { if ((ik_data->flag & CONSTRAINT_SPLINEIK_NO_CURVERAD) == 0) {
mul_v3_fl(poseMat[0], radius); mul_v3_fl(pose_mat[0], radius);
mul_v3_fl(poseMat[2], radius); mul_v3_fl(pose_mat[2], radius);
} }
/* Blend the scaling of the matrix according to the influence. */ /* Blend the scaling of the matrix according to the influence. */
sub_m3_m3m3(poseMat, poseMat, basePoseMat); sub_m3_m3m3(pose_mat, pose_mat, base_pose_mat);
madd_m3_m3m3fl(poseMat, basePoseMat, poseMat, tree->con->enforce * tailBlendFac); madd_m3_m3m3fl(pose_mat, base_pose_mat, pose_mat, tree->con->enforce * tail_blend_fac);
/* step 5: set the location of the bone in the matrix */ /* Step 5: Set the location of the bone in the matrix. */
if (ikData->flag & CONSTRAINT_SPLINEIK_NO_ROOT) { if (ik_data->flag & CONSTRAINT_SPLINEIK_NO_ROOT) {
/* when the 'no-root' option is affected, the chain can retain /* When the 'no-root' option is affected, the chain can retain
* the shape but be moved elsewhere * the shape but be moved elsewhere.
*/ */
copy_v3_v3(poseHead, origHead); copy_v3_v3(pose_head, orig_head);
} }
else if (tree->con->enforce < 1.0f) { else if (tree->con->enforce < 1.0f) {
/* when the influence is too low /* When the influence is too low:
* - blend the positions for the 'root' bone * - Blend the positions for the 'root' bone.
* - stick to the parent for any other * - Stick to the parent for any other.
*/ */
if (index < tree->chainlen - 1) { if (index < tree->chainlen - 1) {
copy_v3_v3(poseHead, origHead); copy_v3_v3(pose_head, orig_head);
} }
else { else {
interp_v3_v3v3(poseHead, origHead, poseHead, tree->con->enforce); interp_v3_v3v3(pose_head, orig_head, pose_head, tree->con->enforce);
} }
} }
/* finally, store the new transform */ /* Finally, store the new transform. */
copy_m4_m3(pchan->pose_mat, poseMat); copy_m4_m3(pchan->pose_mat, pose_mat);
copy_v3_v3(pchan->pose_mat[3], poseHead); copy_v3_v3(pchan->pose_mat[3], pose_head);
copy_v3_v3(pchan->pose_head, poseHead); copy_v3_v3(pchan->pose_head, pose_head);
mul_v3_mat3_m4v3(origTail, state->locrot_offset, pchan->pose_tail); mul_v3_mat3_m4v3(orig_tail, state->locrot_offset, pchan->pose_tail);
/* recalculate tail, as it's now outdated after the head gets adjusted above! */ /* Recalculate tail, as it's now outdated after the head gets adjusted above! */
BKE_pose_where_is_bone_tail(pchan); BKE_pose_where_is_bone_tail(pchan);
/* update the offset in the accumulated parent transform */ /* Update the offset in the accumulated parent transform. */
sub_v3_v3v3(state->locrot_offset[3], pchan->pose_tail, origTail); sub_v3_v3v3(state->locrot_offset[3], pchan->pose_tail, orig_tail);
/* done! */ /* Done! */
pchan->flag |= POSE_DONE; pchan->flag |= POSE_DONE;
} }
/* Evaluate the chain starting from the nominated bone */ /* Evaluate the chain starting from the nominated bone */
static void splineik_execute_tree( static void splineik_execute_tree(
struct Depsgraph *depsgraph, Scene *scene, Object *ob, bPoseChannel *pchan_root, float ctime) struct Depsgraph *depsgraph, Scene *scene, Object *ob, bPoseChannel *pchan_root, float ctime)
{ {
tSplineIK_Tree *tree; tSplineIK_Tree *tree;
/* for each pose-tree, execute it if it is spline, otherwise just free it */ /* for each pose-tree, execute it if it is spline, otherwise just free it */
while ((tree = pchan_root->siktree.first) != NULL) { while ((tree = pchan_root->siktree.first) != NULL) {
/* Firstly, calculate the bone matrix the standard way, /* Firstly, calculate the bone matrix the standard way,
* since this is needed for roll control. */ * since this is needed for roll control. */
for (int i = tree->chainlen - 1; i >= 0; i--) { for (int i = tree->chainlen - 1; i >= 0; i--) {
BKE_pose_where_is_bone(depsgraph, scene, ob, tree->chain[i], ctime, 1); BKE_pose_where_is_bone(depsgraph, scene, ob, tree->chain[i], ctime, 1);
} }
/* After that, evaluate the actual Spline IK, unless there are missing dependencies. */ /* After that, evaluate the actual Spline IK, unless there are missing dependencies. */
tSplineIk_EvalState state; tSplineIk_EvalState state;
if (splineik_evaluate_init(tree, &state)) { if (splineik_evaluate_init(tree, &state)) {
/* Walk over each bone in the chain, calculating the effects of spline IK /* Walk over each bone in the chain, calculating the effects of spline IK
* - the chain is traversed in the opposite order to storage order (i.e. parent to children) * - the chain is traversed in the opposite order to storage order
* so that dependencies are correct * (i.e. parent to children) so that dependencies are correct
*/ */
for (int i = tree->chainlen - 1; i >= 0; i--) { for (int i = tree->chainlen - 1; i >= 0; i--) {
bPoseChannel *pchan = tree->chain[i]; bPoseChannel *pchan = tree->chain[i];
splineik_evaluate_bone(tree, ob, pchan, i, &state); splineik_evaluate_bone(tree, ob, pchan, i, &state);
} }
} }
/* free the tree info specific to SplineIK trees now */ /* free the tree info specific to SplineIK trees now */
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