From d6c245a2f3268661e49c937187277339a16c1889 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 12 Dec 2016 10:23:50 +0000
Subject: [PATCH] Added create angle of 20 degrees to SmoothingVisitor to
 improve visual quality. Added geometry.setUseVertexBufferObjects(true) to
 geometry set up for improved performance. Refactored the color set up so that
 by default it assigns just a single color to the geometry to improve
 performance.

---
 .../OpenCASCADE/ReaderWriterOpenCASCADE.cpp   | 21 ++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/osgPlugins/OpenCASCADE/ReaderWriterOpenCASCADE.cpp b/src/osgPlugins/OpenCASCADE/ReaderWriterOpenCASCADE.cpp
index 080c504dd..e1148bf60 100644
--- a/src/osgPlugins/OpenCASCADE/ReaderWriterOpenCASCADE.cpp
+++ b/src/osgPlugins/OpenCASCADE/ReaderWriterOpenCASCADE.cpp
@@ -156,14 +156,26 @@ osg::ref_ptr<osg::Geometry> ReaderWritterOpenCASCADE::OCCTKReader::_createGeomet
 {
     // vector to save vertices
     osg::ref_ptr<osg::Vec3Array> vertexList = new osg::Vec3Array();
+
+
+    osg::Array::Binding colorBinding = osg::Array::BIND_OVERALL;
+
     // vector to save _colorTool
     osg::ref_ptr<osg::Vec3Array> colorList = new osg::Vec3Array();
+    if (colorBinding==osg::Array::BIND_OVERALL)
+    {
+        colorList->push_back(geomColor);
+    }
 
     // create one osg primitive set
     osg::ref_ptr<osg::DrawElementsUInt> triangleStrip = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES, 0);
     unsigned int noOfTriangles = 0;
 
     osg::ref_ptr<osg::Geometry> geom = new osg::Geometry;
+
+    // large vertex datasets work best with VBO.
+    geom->setUseVertexBufferObjects(true);
+
     if(!shape.IsNull())
     {
         // clean any previous triangulation
@@ -204,7 +216,10 @@ osg::ref_ptr<osg::Geometry> ReaderWritterOpenCASCADE::OCCTKReader::_createGeomet
                     vertexList->push_back(osg::Vec3(pt.X(), pt.Y(), pt.Z()));
 
                     // populate color list
-                    colorList->push_back(geomColor);
+                    if (colorBinding==osg::Array::BIND_PER_VERTEX)
+                    {
+                        colorList->push_back(geomColor);
+                    }
                 }
 
                 /// now we need to get face indices for triangles
@@ -241,8 +256,7 @@ osg::ref_ptr<osg::Geometry> ReaderWritterOpenCASCADE::OCCTKReader::_createGeomet
 
         geom->setVertexArray(vertexList.get());
 
-        geom->setColorArray(colorList.get());
-        geom->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
+        geom->setColorArray(colorList.get(), colorBinding);
 
         #ifdef _LOG_DEBUG_
             std::cout << "Adding Primitive set" << std::endl;
@@ -344,6 +358,7 @@ osg::ref_ptr<osg::Geode> ReaderWritterOpenCASCADE::OCCTKReader::igesToOSGGeode(c
     #endif
 
     osgUtil::SmoothingVisitor sv;
+    sv.setCreaseAngle(osg::DegreesToRadians(20.0));
     _modelGeode->accept(sv);
 
     return _modelGeode;