Rigging Goodies: Spline IK Constraint

At last, this commit introduces the Spline IK Constraint to Blender. Spline IK is a constraint that makes n bones follow the shape of a specified curve. 

Simply add a chain of bones, add a curve, add a Spline IK Constraint to the tip bone and set the number of bones in the chain to make it work. Or, try the following test file:
http://download.blender.org/ftp/incoming/250_splineik_spine01.blend

Screenshots of this in action (as proof):
http://download.blender.org/ftp/incoming/b250_splineik_001_before.png
http://download.blender.org/ftp/incoming/b250_splineik_001_after.png

I've implemented this in a similar way to how standard IK solvers are done. However, this code is currently not an IK plugin, since I imagine that it would be useful to be able to combine the 2 types of IK. This can be easily changed though :)

Finally, a few notes on what to expect still:
* Constraint blending currently doesn't affect this. Getting that to work correctly will take a bit more work still.
* Options for not affecting the root joint (to make it easier to attach the chain to a stump or whatever), and non-uniform scaling options have yet to be added. I've marked the places where they can be added though
* Control over the twisting of the chain still needs investigation. 

Have fun!

1 files changed, 2 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/depsgraph.c b/source/blender/blenkernel/intern/depsgraph.c
index d60a26e8feb..36568ee5667 100644
--- a/source/blender/blenkernel/intern/depsgraph.c
+++ b/source/blender/blenkernel/intern/depsgraph.c
@@ -399,7 +399,7 @@ static void build_dag_object(DagForest *dag, DagNode *scenenode, Scene *scene, O
 								
 								if (ct->subtarget[0])
 									dag_add_relation(dag,node3,node, DAG_RL_OB_DATA|DAG_RL_DATA_DATA, cti->name);
-								else if(ELEM(con->type, CONSTRAINT_TYPE_FOLLOWPATH, CONSTRAINT_TYPE_CLAMPTO)) 	
+								else if(ELEM3(con->type, CONSTRAINT_TYPE_FOLLOWPATH, CONSTRAINT_TYPE_CLAMPTO, CONSTRAINT_TYPE_SPLINEIK)) 	
 									dag_add_relation(dag,node3,node, DAG_RL_DATA_DATA|DAG_RL_OB_DATA, cti->name);
 								else
 									dag_add_relation(dag,node3,node, DAG_RL_OB_DATA, cti->name);
@@ -2407,7 +2407,7 @@ void DAG_pose_sort(Object *ob)
 						bPoseChannel *target= get_pose_channel(ob->pose, ct->subtarget);
 						if (target) {
 							node2= dag_get_node(dag, target);
-							dag_add_relation(dag, node2, node, 0, "IK Constraint");
+							dag_add_relation(dag, node2, node, 0, "Pose Constraint");
 							
 							if (con->type==CONSTRAINT_TYPE_KINEMATIC) {
 								bKinematicConstraint *data = (bKinematicConstraint *)con->data;