From 8ef3c42f80c2227ece7500c809f44946467e6fab Mon Sep 17 00:00:00 2001
From: Brecht Van Lommel <brechtvanlommel@pandora.be>
Date: Tue, 14 May 2013 16:22:53 +0000
Subject: [PATCH] Fix #35347: constraints with vertex group targets were not
 using the vertex group weights, it assumed all weights were 1. This gave very
 different results with the new bevel modifier due to slightly different
 vertex group interpolation.

---
 source/blender/blenkernel/intern/constraint.c | 20 ++++++++++---------
 source/blender/blenkernel/intern/customdata.c |  8 ++++++--
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index af5a20e97b4..cee796c4cab 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -380,29 +380,31 @@ static void contarget_get_mesh_mat(Object *ob, const char *substring, float mat[
 	if (dm) {
 		MDeformVert *dvert = dm->getVertDataArray(dm, CD_MDEFORMVERT);
 		int numVerts = dm->getNumVerts(dm);
-		int i, count = 0;
+		int i;
 		float co[3], nor[3];
 		
 		/* check that dvert is a valid pointers (just in case) */
 		if (dvert) {
 			MDeformVert *dv = dvert;
+			float weightsum = 0.0f;
+
 			/* get the average of all verts with that are in the vertex-group */
 			for (i = 0; i < numVerts; i++, dv++) {
 				MDeformWeight *dw = defvert_find_index(dv, defgroup);
-				if (dw && dw->weight != 0.0f) {
+
+				if (dw && dw->weight > 0.0f) {
 					dm->getVertCo(dm, i, co);
 					dm->getVertNo(dm, i, nor);
-					add_v3_v3(vec, co);
-					add_v3_v3(normal, nor);
-					count++;
-					
+					madd_v3_v3fl(vec, co, dw->weight);
+					madd_v3_v3fl(normal, nor, dw->weight);
+					weightsum += dw->weight;
 				}
 			}
 
 			/* calculate averages of normal and coordinates */
-			if (count > 0) {
-				mul_v3_fl(vec, 1.0f / count);
-				mul_v3_fl(normal, 1.0f / count);
+			if (weightsum > 0) {
+				mul_v3_fl(vec, 1.0f / weightsum);
+				mul_v3_fl(normal, 1.0f / weightsum);
 			}
 			
 			
diff --git a/source/blender/blenkernel/intern/customdata.c b/source/blender/blenkernel/intern/customdata.c
index 879d1895513..75000ec440b 100644
--- a/source/blender/blenkernel/intern/customdata.c
+++ b/source/blender/blenkernel/intern/customdata.c
@@ -239,12 +239,16 @@ static void layerInterp_mdeformvert(void **sources, const float *weights,
 
 		for (j = 0; j < source->totweight; ++j) {
 			MDeformWeight *dw = &source->dw[j];
+			float weight = dw->weight * interp_weight;
+
+			if (weight == 0.0f)
+				continue;
 
 			for (node = dest_dw; node; node = node->next) {
 				MDeformWeight *tmp_dw = (MDeformWeight *)node->link;
 
 				if (tmp_dw->def_nr == dw->def_nr) {
-					tmp_dw->weight += dw->weight * interp_weight;
+					tmp_dw->weight += weight;
 					break;
 				}
 			}
@@ -254,7 +258,7 @@ static void layerInterp_mdeformvert(void **sources, const float *weights,
 				MDeformWeight *tmp_dw = MEM_callocN(sizeof(*tmp_dw),
 				                                    "layerInterp_mdeformvert tmp_dw");
 				tmp_dw->def_nr = dw->def_nr;
-				tmp_dw->weight = dw->weight * interp_weight;
+				tmp_dw->weight = weight;
 				BLI_linklist_prepend(&dest_dw, tmp_dw);
 				totweight++;
 			}