DRTVWR-542 Fix malfunctioning warning

2 files changed, 17 insertions, 6 deletions

diff --git a/indra/llmath/llvolume.h b/indra/llmath/llvolume.h
index a77e8c08c6..c0b224b1ff 100644
--- a/indra/llmath/llvolume.h
+++ b/indra/llmath/llvolume.h
@@ -936,17 +936,23 @@ public:
 	LLVector4a* mCenter;
 	LLVector2   mTexCoordExtents[2]; //minimum and maximum of texture coordinates of the face.
 
-	S32 mNumVertices;
+	S32 mNumVertices; // num vertices == num normals == num texcoords
 	S32 mNumAllocatedVertices;
 	S32 mNumIndices;
 
-	LLVector4a* mPositions;
-	LLVector4a* mNormals;
+	LLVector4a* mPositions; // Contains vertices, nortmals and texcoords
+	LLVector4a* mNormals; // pointer into mPositions
 	LLVector4a* mTangents;
-	LLVector2*  mTexCoords;
+	LLVector2*  mTexCoords; // pointer into mPositions
+
+	// mIndices contains mNumIndices amount of elements.
+	// It contains triangles, each 3 indices describe one triangle.
+    // If mIndices contains {0, 2, 3, 1, 2, 4}, it means there
+    // are two triangles {0, 2, 3} and {1, 2, 4} with values being
+    // indexes for mPositions/mNormals/mTexCoords
 	U16* mIndices;
 
-	//vertex buffer filled in by LLFace to cache this volume face geometry in vram 
+	// vertex buffer filled in by LLFace to cache this volume face geometry in vram 
 	// (declared as a LLPointer to LLRefCount to avoid dependency on LLVertexBuffer)
 	mutable LLPointer<LLRefCount> mVertexBuffer; 
 
diff --git a/indra/llprimitive/lldaeloader.cpp b/indra/llprimitive/lldaeloader.cpp
index dfa29fb539..d3acd44f06 100644
--- a/indra/llprimitive/lldaeloader.cpp
+++ b/indra/llprimitive/lldaeloader.cpp
@@ -787,7 +787,12 @@ LLModel::EModelStatus load_face_from_dom_polygons(std::vector<LLVolumeFace>& fac
 	for (U32 i = 0; i < verts.size(); ++i)
 	{
 		indices[i] = vert_idx[verts[i]];
-		llassert(!i || (indices[i-1] != indices[i]));
+        if (i % 3 != 0) // assumes GL_TRIANGLES, compare 0-1, 1-2, 3-4, 4-5 but not 2-3 or 5-6
+        {
+            // A faulty degenerate triangle detection (triangle with 0 area),
+            // probably should be a warning and not an assert
+            llassert(!i || (indices[i-1] != indices[i]));
+        }
 	}
 
 	// DEBUG just build an expanded triangle list