Bugfix #21384: Bone Driven Shapekeys Child Evaluation Problem

Transform channel drivers for bones in 'localspace' was using the wrong matrix when getting the transforms. I had been assuming that pchan->chan_mat always contained only the matrix-ised transform values stored in the pchan (which is true while constraints are being evaluated, but not afterwards). 

Changes:
- Added a new function to calculate this matrix instead of directly writing it on the pchan->chan_matrix field. 
- Also, made the normalisation of the quaternion values during this process be done on a temp var instead of on the stored value. This was a constant source of confusion in the past, so let's see if we can do without it now :)

Unrelated to this commit, I've also fixed a compiler warning with previous commit that I missed (missing include).

1 files changed, 7 insertions, 3 deletions

diff --git a/source/blender/blenkernel/intern/fcurve.c b/source/blender/blenkernel/intern/fcurve.c
index bd29bd55428..807a723685a 100644
--- a/source/blender/blenkernel/intern/fcurve.c
+++ b/source/blender/blenkernel/intern/fcurve.c
@@ -50,7 +50,7 @@
 #include "BKE_fcurve.h"
 #include "BKE_animsys.h"
 #include "BKE_action.h"
-
+#include "BKE_armature.h"
 #include "BKE_curve.h" 
 #include "BKE_global.h"
 #include "BKE_idprop.h"
@@ -1041,8 +1041,12 @@ static float dvar_eval_transChan (ChannelDriver *driver, DriverVar *dvar)
 			useEulers = 1;
 		}
 		
-		if (dtar->flag & DTAR_FLAG_LOCALSPACE)
-			copy_m4_m4(mat, pchan->chan_mat);
+		if (dtar->flag & DTAR_FLAG_LOCALSPACE) {
+			/* specially calculate local matrix, since chan_mat is not valid 
+			 * since it stores delta transform of pose_mat so that deforms work
+			 */
+			pchan_to_mat4(pchan, mat);
+		}
 		else
 			mul_m4_m4m4(mat, pchan->pose_mat, ob->obmat);
 	}