1 files changed, 93 insertions, 0 deletions
diff --git a/core/voxelize.cpp b/core/voxelize.cpp
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+++ b/core/voxelize.cpp
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+// This code contains NVIDIA Confidential Information and is disclosed to you
+// under a form of NVIDIA software license agreement provided separately to you.
+//
+// Notice
+// NVIDIA Corporation and its licensors retain all intellectual property and
+// proprietary rights in and to this software and related documentation and
+// any modifications thereto. Any use, reproduction, disclosure, or
+// distribution of this software and related documentation without an express
+// license agreement from NVIDIA Corporation is strictly prohibited.
+//
+// ALL NVIDIA DESIGN SPECIFICATIONS, CODE ARE PROVIDED "AS IS.". NVIDIA MAKES
+// NO WARRANTIES, EXPRESSED, IMPLIED, STATUTORY, OR OTHERWISE WITH RESPECT TO
+// THE MATERIALS, AND EXPRESSLY DISCLAIMS ALL IMPLIED WARRANTIES OF NONINFRINGEMENT,
+// MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE.
+//
+// Information and code furnished is believed to be accurate and reliable.
+// However, NVIDIA Corporation assumes no responsibility for the consequences of use of such
+// information or for any infringement of patents or other rights of third parties that may
+// result from its use. No license is granted by implication or otherwise under any patent
+// or patent rights of NVIDIA Corporation. Details are subject to change without notice.
+// This code supersedes and replaces all information previously supplied.
+// NVIDIA Corporation products are not authorized for use as critical
+// components in life support devices or systems without express written approval of
+// NVIDIA Corporation.
+//
+// Copyright (c) 2013-2016 NVIDIA Corporation. All rights reserved.
+
+#include "aabbtree.h"
+#include "mesh.h"
+
+void Voxelize(const float* vertices, int numVertices, const int* indices, int numTriangleIndices, uint32_t width, uint32_t height, uint32_t depth, uint32_t* volume, Vec3 minExtents, Vec3 maxExtents)
+{
+	memset(volume, 0, sizeof(uint32_t)*width*height*depth);
+
+	// build an aabb tree of the mesh
+	AABBTree tree((const Vec3*)vertices, numVertices, (const uint32_t*)indices, numTriangleIndices/3); 
+
+	// parity count method, single pass
+	const Vec3 extents(maxExtents-minExtents);
+	const Vec3 delta(extents.x/width, extents.y/height, extents.z/depth);
+	const Vec3 offset(0.5f*delta.x, 0.5f*delta.y, 0.5f*delta.z);
+	
+	// this is the bias we apply to step 'off' a triangle we hit, not very robust
+	const float eps = 0.00001f*extents.z;
+
+	for (uint32_t x=0; x < width; ++x)
+	{
+		for (uint32_t y=0; y < height; ++y)
+		{
+			bool inside = false;
+
+			Vec3 rayDir = Vec3(0.0f, 0.0f, 1.0f);
+			Vec3 rayStart = minExtents + Vec3(x*delta.x + offset.x, y*delta.y + offset.y, 0.0f);
+
+			uint32_t lastTri = uint32_t(-1);
+			for (;;)
+			{
+				// calculate ray start
+				float t, u, v, w, s;
+				uint32_t tri;
+
+				if (tree.TraceRay(rayStart, rayDir, t, u, v, w, s, tri))
+				{
+					// calculate cell in which intersection occurred
+					const float zpos = rayStart.z + t*rayDir.z;
+					const float zhit = (zpos-minExtents.z)/delta.z;
+					
+					uint32_t z = uint32_t(floorf((rayStart.z-minExtents.z)/delta.z + 0.5f));
+					uint32_t zend = std::min(uint32_t(floorf(zhit + 0.5f)), depth-1);
+
+					if (inside)
+					{
+						// march along column setting bits 
+						for (uint32_t k=z; k < zend; ++k)
+							volume[k*width*height + y*width + x] = uint32_t(-1);
+					}
+					
+					inside = !inside;
+					
+					// we hit the tri we started from
+					if (tri == lastTri)
+						printf("Error self-intersect\n");
+					lastTri = tri;
+
+					rayStart += rayDir*(t+eps);
+
+				}
+				else
+					break;
+			}
+		}
+	}	
+}