From 184ae997d60d0d5a7d325ba4f2f8e1a1694b2c77 Mon Sep 17 00:00:00 2001
From: barry <barry.fowler@dreamworks.com>
Date: Wed, 24 Apr 2019 14:56:49 -0700
Subject: [PATCH] Fixed single-crease patch isolation now required without
 boundary isolation:     - added member to FeatureMask for single-crease
 option without inf-sharp     - adjusted adaptive refinement to handle
 unisolated interior sharp edges

---
 opensubdiv/far/topologyRefiner.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/opensubdiv/far/topologyRefiner.cpp b/opensubdiv/far/topologyRefiner.cpp
index 7f461ab6..4b1d0431 100644
--- a/opensubdiv/far/topologyRefiner.cpp
+++ b/opensubdiv/far/topologyRefiner.cpp
@@ -318,6 +318,8 @@ namespace internal {
         int_type selectInfSharpIrregularCrease : 1;
         int_type selectInfSharpIrregularCorner : 1;
 
+        int_type selectUnisolatedInteriorEdge : 1;
+
         int_type selectNonManifold  : 1;
         int_type selectFVarFeatures : 1;
     };
@@ -355,6 +357,8 @@ namespace internal {
         selectInfSharpIrregularCrease = true;
         selectInfSharpIrregularCorner = true;
 
+        selectUnisolatedInteriorEdge = useSingleCreasePatch && !options.useInfSharpPatch;
+
         selectNonManifold  = true;
         selectFVarFeatures = options.considerFVarChannels;
     }
@@ -570,6 +574,13 @@ namespace {
                 return doesInfSharpVTagHaveFeatures(compVTag, featureMask);
             } else if (isolateQuadBoundaries) {
                 return true;
+            } else if (featureMask.selectUnisolatedInteriorEdge) {
+                //  Needed for single-crease approximation to inf-sharp interior edge:
+                for (int i = 0; i < 4; ++i) {
+                    if (vTags[i]._infSharpEdges && !vTags[i]._boundary) {
+                        return true;
+                    }
+                }
             }
         } else {
             if (atLeastOneSmoothCorner && !compVTag._boundary) {