RNA: expose access to B-Bone shape data from Python.

B-Bone shape is a non-trivial computation, so access to
the results would be useful for Python scripts working with
B-Bones, e.g. rig generation.

This exposes both final segment matrices, and the tangent
vectors computed from the custom handle bones.

Since the handle tangents use the axis+roll orientation math
of edit bones, add matrix conversion static methods to Bone.

Reviewers: campbellbarton

Differential Revision: https://developer.blender.org/D3983

1 files changed, 9 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/armature_update.c b/source/blender/blenkernel/intern/armature_update.c
index b917aae08de..f5519966ac2 100644
--- a/source/blender/blenkernel/intern/armature_update.c
+++ b/source/blender/blenkernel/intern/armature_update.c
@@ -715,17 +715,24 @@ void BKE_pose_bone_done(struct Depsgraph *depsgraph,
 		copy_v3_v3(pchan_orig->pose_head, pchan->pose_mat[3]);
 		copy_m4_m4(pchan_orig->constinv, pchan->constinv);
 		BKE_pose_where_is_bone_tail(pchan_orig);
+		if (pchan->bone == NULL || pchan->bone->segments <= 1) {
+			BKE_pose_channel_free_bbone_cache(pchan_orig);
+		}
 	}
 }
 
 void BKE_pose_eval_bbone_segments(struct Depsgraph *depsgraph,
-                               struct Object *ob,
-                               int pchan_index)
+                                  struct Object *ob,
+                                  int pchan_index)
 {
 	bPoseChannel *pchan = pose_pchan_get_indexed(ob, pchan_index);
 	DEG_debug_print_eval(depsgraph, __func__, pchan->name, pchan);
 	if (pchan->bone != NULL && pchan->bone->segments > 1) {
 		BKE_pchan_cache_bbone_segments(pchan);
+		bArmature *arm = (bArmature *)ob->data;
+		if (DEG_is_active(depsgraph) && arm->edbo == NULL) {
+			BKE_pchan_copy_bbone_segments_cache(pchan->orig_pchan, pchan);
+		}
 	}
 }