polyvox/tests/TestSurfaceExtractor.cpp
2015-12-26 21:45:41 +00:00

232 lines
10 KiB
C++

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#include "TestSurfaceExtractor.h"
#include "PolyVox/Density.h"
#include "PolyVox/FilePager.h"
#include "PolyVox/MaterialDensityPair.h"
#include "PolyVox/RawVolume.h"
#include "PolyVox/PagedVolume.h"
#include "PolyVox/MarchingCubesSurfaceExtractor.h"
#include <QtTest>
#include <random>
using namespace PolyVox;
// Test our ability to modify the behaviour of the MarchingCubesSurfaceExtractor. This simple example only modifies
// the threshold (and actually this can be achieved by passing a parameter to the constructor of the
// DefaultMarchingCubesController) but you could implement custom behaviour in the other members
// if you wanted too. Actually, it's not clear if this ability is really useful because I can't think
// what you'd modify apart from the threshold but the ability is at least available. Also, the
// DefaultMarchingCubesController is templatised whereas this exmple shows that controllers don't
// have to be.
class CustomMarchingCubesController
{
public:
typedef float DensityType;
typedef float MaterialType;
float convertToDensity(float voxel)
{
return voxel;
}
float convertToMaterial(float /*voxel*/)
{
return 1.0f;
}
float blendMaterials(float /*a*/, float /*b*/, float /*weight*/)
{
return 1.0f;
}
float getThreshold(void)
{
return 50.0f;
}
};
// These 'writeDensityValueToVoxel' functions provide a unified interface for writting densities to primative and class voxel types.
// They are conceptually the inverse of the 'convertToDensity' function used by the MarchingCubesSurfaceExtractor. They probably shouldn't be part
// of PolyVox, but they might be usful to other tests so we cold move them into a 'Tests.h' or something in the future.
template<typename VoxelType>
void writeDensityValueToVoxel(int valueToWrite, VoxelType& voxel)
{
voxel = valueToWrite;
}
template<>
void writeDensityValueToVoxel(int valueToWrite, MaterialDensityPair88& voxel)
{
voxel.setDensity(valueToWrite);
}
template<typename VoxelType>
void writeMaterialValueToVoxel(int /*valueToWrite*/, VoxelType& /*voxel*/)
{
//Most types don't have a material
return;
}
template<>
void writeMaterialValueToVoxel(int valueToWrite, MaterialDensityPair88& voxel)
{
voxel.setMaterial(valueToWrite);
}
template <typename VolumeType>
VolumeType* createAndFillVolume(void)
{
const int32_t uVolumeSideLength = 64;
//Create empty volume
VolumeType* volData = new VolumeType(Region(0, 0, 0, uVolumeSideLength - 1, uVolumeSideLength - 1, uVolumeSideLength - 1));
// Fill
for (int32_t z = 0; z < uVolumeSideLength; z++)
{
for (int32_t y = 0; y < uVolumeSideLength; y++)
{
for (int32_t x = 0; x < uVolumeSideLength; x++)
{
// Create a density field which changes throughout the volume. It's
// zero in the lower corner and increasing as the coordinates increase.
typename VolumeType::VoxelType voxelValue;
writeDensityValueToVoxel<typename VolumeType::VoxelType>(x + y + z, voxelValue);
writeMaterialValueToVoxel<typename VolumeType::VoxelType>(z > uVolumeSideLength / 2 ? 42 : 79, voxelValue);
volData->setVoxel(x, y, z, voxelValue);
}
}
}
return volData;
}
template <typename VolumeType>
VolumeType* createAndFillVolumeWithNoise(int32_t iVolumeWidthAndHeight, int32_t iVolumeDepth, float minValue, float maxValue)
{
FilePager<float>* pager = new FilePager<float>(".");
//Create empty volume
VolumeType* volData = new VolumeType(pager);
// Set up a random number generator
std::mt19937 rng;
// Fill
for (int32_t z = 0; z < iVolumeDepth; z++)
{
for (int32_t y = 0; y < iVolumeWidthAndHeight; y++)
{
for (int32_t x = 0; x < iVolumeWidthAndHeight; x++)
{
// We can't use std distributions because they vary between platforms (breaking tests)
float voxelValue = static_cast<float>(rng()) / static_cast<float>(std::numeric_limits<int32_t>::max()); // Float in range 0.0 to 1.0
voxelValue = voxelValue * (maxValue - minValue) + minValue; // Float in range minValue to maxValue
volData->setVoxel(x, y, z, voxelValue);
}
}
}
return volData;
}
void TestSurfaceExtractor::testBehaviour()
{
// These tests apply the Marching Cubes surface extractor to volumes of various voxel types. In addition we sometimes make use of custom controllers
// and user-provided meshes to make sure these various combinations work as expected.
//
// It is also noted that the number of indices and vertices is varying quite significantly based on the voxel type. This seems unexpected, but could
// be explained if some overflow is occuring when writing data into the volume, causing volumes of different voxel types to have different distributions.
// Of course, the use of a custom controller will also make a significant diference, but this probably does need investigating further in the future.
// This basic test just uses the default controller and automatically generates a mesh of the appropriate type.
auto uintVol = createAndFillVolume< RawVolume<uint8_t> >();
auto uintMesh = extractMarchingCubesMesh(uintVol, uintVol->getEnclosingRegion());
QCOMPARE(uintMesh.getNoOfVertices(), uint32_t(6048)); // Verifies size of mesh and that we have 32-bit indices
QCOMPARE(uintMesh.getNoOfIndices(), uint32_t(35157)); // Verifies size of mesh
QCOMPARE(uintMesh.getIndex(100), uint32_t(24)); // Verifies that we have 32-bit indices
QCOMPARE(uintMesh.getVertex(100).data, uint8_t(1)); // Not really meaningful for a primative type
// This test makes use of a custom controller
auto floatVol = createAndFillVolume< RawVolume<float> >();
CustomMarchingCubesController floatCustomController;
auto floatMesh = extractMarchingCubesMesh(floatVol, floatVol->getEnclosingRegion(), floatCustomController);
QCOMPARE(floatMesh.getNoOfVertices(), uint32_t(3825)); // Verifies size of mesh and that we have 32-bit indices
QCOMPARE(floatMesh.getNoOfIndices(), uint32_t(22053)); // Verifies size of mesh
QCOMPARE(floatMesh.getIndex(100), uint32_t(119)); // Verifies that we have 32-bit indices
QCOMPARE(floatMesh.getVertex(100).data, float(1.0f)); // Not really meaningful for a primative type
// This test makes use of a user provided mesh. It uses the default controller, but we have to explicitly provide this because C++ won't let us
// use a default for the second-to-last parameter but noot use a default for the last parameter.
auto intVol = createAndFillVolume< RawVolume<int8_t> >();
Mesh< MarchingCubesVertex< int8_t >, uint16_t > intMesh;
extractMarchingCubesMeshCustom(intVol, intVol->getEnclosingRegion(), &intMesh);
QCOMPARE(intMesh.getNoOfVertices(), uint16_t(5859)); // Verifies size of mesh and that we have 16-bit indices
QCOMPARE(intMesh.getNoOfIndices(), uint32_t(34041)); // Verifies size of mesh
QCOMPARE(intMesh.getIndex(100), uint16_t(29)); // Verifies that we have 16-bit indices
QCOMPARE(intMesh.getVertex(100).data, int8_t(1)); // Not really meaningful for a primative type
// This test makes use of a user-provided mesh and also a custom controller.
auto doubleVol = createAndFillVolume< RawVolume<double> >();
CustomMarchingCubesController doubleCustomController;
Mesh< MarchingCubesVertex< double >, uint16_t > doubleMesh;
extractMarchingCubesMeshCustom(doubleVol, doubleVol->getEnclosingRegion(), &doubleMesh, doubleCustomController);
QCOMPARE(doubleMesh.getNoOfVertices(), uint16_t(3825)); // Verifies size of mesh and that we have 32-bit indices
QCOMPARE(doubleMesh.getNoOfIndices(), uint32_t(22053)); // Verifies size of mesh
QCOMPARE(doubleMesh.getIndex(100), uint16_t(119)); // Verifies that we have 32-bit indices
QCOMPARE(doubleMesh.getVertex(100).data, double(1.0f)); // Not really meaningful for a primative type
// This test ensures the extractor works on a non-primitive voxel type.
auto materialVol = createAndFillVolume< RawVolume<MaterialDensityPair88> >();
auto materialMesh = extractMarchingCubesMesh(materialVol, materialVol->getEnclosingRegion());
QCOMPARE(materialMesh.getNoOfVertices(), uint32_t(6048)); // Verifies size of mesh and that we have 32-bit indices
QCOMPARE(materialMesh.getNoOfIndices(), uint32_t(35157)); // Verifies size of mesh
QCOMPARE(materialMesh.getIndex(100), uint32_t(24)); // Verifies that we have 32-bit indices
QCOMPARE(materialMesh.getVertex(100).data.getMaterial(), uint16_t(79)); // Verify the data attached to the vertex
}
void TestSurfaceExtractor::testEmptyVolumePerformance()
{
auto emptyVol = createAndFillVolumeWithNoise< PagedVolume<float> >(128, 512, -2.0f, -1.0f);
Mesh< MarchingCubesVertex< float >, uint16_t > emptyMesh;
QBENCHMARK{ extractMarchingCubesMeshCustom(emptyVol, Region(8, 8, 8, 119, 119, 503), &emptyMesh); }
QCOMPARE(emptyMesh.getNoOfVertices(), uint16_t(0));
}
void TestSurfaceExtractor::testNoiseVolumePerformance()
{
auto noiseVol = createAndFillVolumeWithNoise< PagedVolume<float> >(128, 128, -1.0f, 1.0f);
Mesh< MarchingCubesVertex< float >, uint16_t > noiseMesh;
QBENCHMARK{ extractMarchingCubesMeshCustom(noiseVol, Region(32, 32, 32, 63, 63, 63), &noiseMesh); }
QCOMPARE(noiseMesh.getNoOfVertices(), uint16_t(35672));
}
QTEST_MAIN(TestSurfaceExtractor)