Fix for CTS-305 'Uploaded meshes have uniform scale'

1 files changed, 44 insertions, 7 deletions

diff --git a/indra/llprimitive/llmodel.cpp b/indra/llprimitive/llmodel.cpp
index 1cee5a6e15..6baf20a726 100644
--- a/indra/llprimitive/llmodel.cpp
+++ b/indra/llprimitive/llmodel.cpp
@@ -875,6 +875,15 @@ void LLModel::optimizeVolumeFaces()
 #endif
 }
 
+// Shrink the model to fit
+// on a 1x1x1 cube centered at the origin.
+// The positions and extents
+// multiplied by  mNormalizedScale
+// and offset by mNormalizedTranslation
+// to be the "original" extents and position.
+// Also, the positions will fit
+// within the unit cube and the extents
+// to be corners of the unit cube.
 void LLModel::normalizeVolumeFaces()
 {
 
@@ -891,6 +900,10 @@ void LLModel::normalizeVolumeFaces()
 			llerrs << "WTF?" << llendl;
 		}
 
+		// For all of the volume faces
+		// in the model, loop over
+		// them and see what the extents
+		// of the volume along each axis.
 		min = mVolumeFaces[0].mExtents[0];
 		max = mVolumeFaces[0].mExtents[1];
 
@@ -907,33 +920,57 @@ void LLModel::normalizeVolumeFaces()
 			update_min_max(min, max, face.mExtents[1]);
 		}
 
+		// Now that we have the extents of the model
+		// we can compute the offset needed to center
+		// the model at the origin.
+
+		// Compute center of the model
+		// and make it negative to get translation
+		// needed to center at origin.
 		LLVector4a trans;
 		trans.setAdd(min, max);
 		trans.mul(-0.5f);
+
+		// Compute the total size along all
+		// axes of the model.
 		LLVector4a size;
 		size.setSub(max, min);
 
-		F32 scale = 1.f/llmax(llmax(size[0], size[1]), size[2]);
+		// To make the model's total size
+		// be the size of the unit cube, compute
+		// a scale factor that can be applied
+		// to do that.
+		LLVector4a scale = LLVector4a(1, 1, 1);
+		scale.setDiv(scale, size);
 
 		for (U32 i = 0; i < mVolumeFaces.size(); ++i)
 		{
 			LLVolumeFace& face = mVolumeFaces[i];
-				
+
+			// We shrink the extents so
+			// that they fall on the corners
+			// of the unit cube.
 			face.mExtents[0].add(trans);
-			face.mExtents[0].mul(scale);
+			face.mExtents[0].setMul(face.mExtents[0], scale);
 
 			face.mExtents[1].add(trans);
-			face.mExtents[1].mul(scale);
+			face.mExtents[1].setMul(face.mExtents[1], scale);
 
+			// For all the positions, we scale
+			// the positions to fit within the unit cube.
 			LLVector4a* pos = (LLVector4a*) face.mPositions;
 			for (U32 j = 0; j < face.mNumVertices; ++j)
 			{
-				pos[j].add(trans);
-				pos[j].mul(scale);
+			 	pos[j].add(trans);
+				pos[j].setMul(pos[j], scale);
 			}
 		}
 
-		mNormalizedScale = LLVector3(1,1,1) / scale;
+		// mNormalizedScale is the scale at which
+		// we would need to multiply the model
+		// by to get the original size of the
+		// model instead of the normalized size.
+		mNormalizedScale.set(size.getF32ptr());
 		mNormalizedTranslation.set(trans.getF32ptr());
 		mNormalizedTranslation *= -1.f; 
 	}