Made an attempt to fix an instability issue in stroke rendering due to a failure

of Normal2DF0D with smooth FEdges.  The fix is to avoid generating new FEdgeSmooth
instances whose length is shorter than epsilon.

1 files changed, 5 insertions, 0 deletions

diff --git a/source/blender/freestyle/intern/view_map/ViewEdgeXBuilder.cpp b/source/blender/freestyle/intern/view_map/ViewEdgeXBuilder.cpp
index 7cf177dedb7..10d5fb0de75 100755
--- a/source/blender/freestyle/intern/view_map/ViewEdgeXBuilder.cpp
+++ b/source/blender/freestyle/intern/view_map/ViewEdgeXBuilder.cpp
@@ -174,6 +174,8 @@ ViewEdge * ViewEdgeXBuilder::BuildSmoothViewEdge(const OWXFaceLayer& iFaceLayer)
   fl!=flend;
   ++fl){
     fe = BuildSmoothFEdge(feprevious, (*fl));
+    if (feprevious && fe == feprevious)
+      continue;
     fe->setViewEdge(newVEdge);
     if(!fefirst)
       fefirst = fe;
@@ -469,6 +471,9 @@ FEdge * ViewEdgeXBuilder::BuildSmoothFEdge(FEdge *feprevious, const OWXFaceLayer
   Vec3r B2(woeb->GetbVertex()->GetVertex());
   Vec3r B(B1+tb*(B2-B1));
 
+  if (feprevious && (B - va->point3D()).norm() < 1e-6)
+	return feprevious;
+
   vb = MakeSVertex(B, false);
   // Set normal:
   Vec3r NB1(ifl.fl->getFace()->GetVertexNormal(woeb->GetaVertex()));