Working version of mesh decimation code which acts directly on vertex/index buffers.

Also initial work on a 'dynamic' mesh for simplification... but this probably won't be needed now.
2010-02-02 23:18:17 +00:00
parent 5c8dd011e7
commit 89c48cdc27
16 changed files with 1445 additions and 24 deletions
--- a/library/PolyVoxCore/source/MeshFace.cpp
+++ b/library/PolyVoxCore/source/MeshFace.cpp
@ -0,0 +1,114 @@
+#pragma region License
+/*******************************************************************************
+Copyright (c) 2005-2009 David Williams
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgment in the product documentation would be
+    appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution. 	
+*******************************************************************************/
+#pragma endregion
+
+#include "MeshFace.h"
+
+#include "MeshEdge.h"
+#include "MeshVertex.h"
+
+#include "Vector.h"
+
+#include <iostream>
+
+namespace PolyVox
+{
+	MeshFace::MeshFace()
+	{
+		m_pEdge = 0;
+	}
+
+	bool MeshFace::isSane(void)
+	{
+		if(m_pEdge == 0)
+		{
+			std::cout << "SANITY CHECK FAIL: Face has no edge attached" << std::endl;
+			return false;
+		}
+
+		return true;
+	}
+
+	Vector3DFloat MeshFace::getNormal(void)
+	{
+		//Find the three vertices
+		Vector3DFloat pV0 = m_pEdge->m_pSrc->m_vertexData.getPosition();
+		Vector3DFloat pV1 = m_pEdge->m_pNextEdge->m_pSrc->m_vertexData.getPosition();
+		Vector3DFloat pV2 = m_pEdge->m_pNextEdge->m_pNextEdge->m_pSrc->m_vertexData.getPosition();
+
+		Vector3DFloat crossProduct = (pV1 - pV0).cross(pV2 - pV0);
+		
+		assert(crossProduct.length() > 0.001);
+
+		crossProduct.normalise();
+
+		return crossProduct;
+	}
+
+	bool MeshFace::collapseFlipsFace(MeshEdge* pEdgeToCollapse)
+	{
+		MeshVertex* pSrc = pEdgeToCollapse->m_pSrc;
+		MeshVertex* pDest = pEdgeToCollapse->m_pDest;
+
+		MeshVertex* pV0 = m_pEdge->m_pSrc;
+		MeshVertex* pV1 = m_pEdge->m_pNextEdge->m_pSrc;
+		MeshVertex* pV2 = m_pEdge->m_pNextEdge->m_pNextEdge->m_pSrc;
+
+		if(pSrc == pV0)
+		{
+			return collapseFlipsFaceImpl(pV1->m_vertexData.getPosition(), pV2->m_vertexData.getPosition(), pSrc->m_vertexData.getPosition(), pDest->m_vertexData.getPosition());
+		}
+		if(pSrc == pV1)
+		{
+			return collapseFlipsFaceImpl(pV0->m_vertexData.getPosition(), pV2->m_vertexData.getPosition(), pSrc->m_vertexData.getPosition(), pDest->m_vertexData.getPosition());
+		}
+		if(pSrc == pV2)
+		{
+			return collapseFlipsFaceImpl(pV0->m_vertexData.getPosition(), pV1->m_vertexData.getPosition(), pSrc->m_vertexData.getPosition(), pDest->m_vertexData.getPosition());
+		}
+
+		return false;
+	}
+
+	bool MeshFace::collapseFlipsFaceImpl(Vector3DFloat fixed0, Vector3DFloat fixed1, Vector3DFloat oldPos, Vector3DFloat newPos)
+	{
+		Vector3DFloat oldCrossProduct = (fixed0 - oldPos).cross(fixed1 - oldPos);
+		Vector3DFloat newCrossProduct = (fixed0 - newPos).cross(fixed1 - newPos);
+
+		if(oldCrossProduct.length() < 0.001f)
+		{
+			return false;
+		}
+
+		if(newCrossProduct.length() < 0.001f)
+		{
+			return false;
+		}
+
+		oldCrossProduct.normalise();
+		newCrossProduct.normalise();
+
+		return oldCrossProduct.dot(newCrossProduct) < 0.999f;
+	}
+}