diff --git a/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.h b/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.h index 0cfdef5b..f5b75bf4 100644 --- a/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.h +++ b/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.h @@ -67,6 +67,131 @@ namespace PolyVox polyvox_function m_funcIsTransparent; }; + + class AmbientOcclusionCalculatorRaycastCallback + { + public: + AmbientOcclusionCalculatorRaycastCallback() + { + } + + bool operator()(const SimpleVolume::Sampler& sampler) + { + return sampler.getVoxel() == 0; + } + }; + + template + void calculateAmbientOcclusion(VolumeType* volInput, Array<3, uint8_t>* arrayResult, Region region, float fRayLength, uint8_t uNoOfSamplesPerOutputElement, polyvox_function funcIsTransparent) + { + Region m_region = region; + typename VolumeType::Sampler m_sampVolume(volInput); + VolumeType* m_volInput = volInput; + Array<3, uint8_t>* m_arrayResult = arrayResult; + float m_fRayLength = fRayLength; + + uint8_t m_uNoOfSamplesPerOutputElement = uNoOfSamplesPerOutputElement; + + uint16_t mRandomUnitVectorIndex = 0; + uint16_t mRandomVectorIndex = 0; + uint16_t mIndexIncreament; + + polyvox_function m_funcIsTransparent = funcIsTransparent; + + //Make sure that the size of the volume is an exact multiple of the size of the array. + assert(m_volInput->getWidth() % arrayResult->getDimension(0) == 0); + assert(m_volInput->getHeight() % arrayResult->getDimension(1) == 0); + assert(m_volInput->getDepth() % arrayResult->getDimension(2) == 0); + + //Our initial indices. It doesn't matter exactly what we set here, but the code below makes + //sure they are different for different regions which helps reduce tiling patterns in the results. + mRandomUnitVectorIndex += m_region.getLowerCorner().getX() + m_region.getLowerCorner().getY() + m_region.getLowerCorner().getZ(); + mRandomVectorIndex += m_region.getLowerCorner().getX() + m_region.getLowerCorner().getY() + m_region.getLowerCorner().getZ(); + + //This value helps us jump around in the array a bit more, so the + //nth 'random' value isn't always followed by the n+1th 'random' value. + mIndexIncreament = 1; + + const int iRatioX = m_volInput->getWidth() / m_arrayResult->getDimension(0); + const int iRatioY = m_volInput->getHeight() / m_arrayResult->getDimension(1); + const int iRatioZ = m_volInput->getDepth() / m_arrayResult->getDimension(2); + + const float fRatioX = iRatioX; + const float fRatioY = iRatioY; + const float fRatioZ = iRatioZ; + const Vector3DFloat v3dRatio(fRatioX, fRatioY, fRatioZ); + + const float fHalfRatioX = fRatioX * 0.5f; + const float fHalfRatioY = fRatioY * 0.5f; + const float fHalfRatioZ = fRatioZ * 0.5f; + const Vector3DFloat v3dHalfRatio(fHalfRatioX, fHalfRatioY, fHalfRatioZ); + + const Vector3DFloat v3dOffset(0.5f,0.5f,0.5f); + + //RaycastResult raycastResult; + //Raycast raycast(m_volInput, Vector3DFloat(0.0f,0.0f,0.0f), Vector3DFloat(1.0f,1.0f,1.0f), raycastResult, polyvox_bind(&PolyVox::AmbientOcclusionCalculator::raycastCallback, this, std::placeholders::_1)); + + //This loop iterates over the bottom-lower-left voxel in each of the cells in the output array + for(uint16_t z = m_region.getLowerCorner().getZ(); z <= m_region.getUpperCorner().getZ(); z += iRatioZ) + { + for(uint16_t y = m_region.getLowerCorner().getY(); y <= m_region.getUpperCorner().getY(); y += iRatioY) + { + for(uint16_t x = m_region.getLowerCorner().getX(); x <= m_region.getUpperCorner().getX(); x += iRatioX) + { + //Compute a start position corresponding to + //the centre of the cell in the output array. + Vector3DFloat v3dStart(x, y, z); + v3dStart -= v3dOffset; + v3dStart += v3dHalfRatio; + + //Keep track of how many rays did not hit anything + uint8_t uVisibleDirections = 0; + + for(int ct = 0; ct < m_uNoOfSamplesPerOutputElement; ct++) + { + //We take a random vector with components going from -1 to 1 and scale it to go from -halfRatio to +halfRatio. + //This jitter value moves our sample point from the center of the array cell to somewhere else in the array cell + Vector3DFloat v3dJitter = randomVectors[(mRandomVectorIndex += (++mIndexIncreament)) % 1019]; //Prime number helps avoid repetition on sucessive loops. + v3dJitter *= v3dHalfRatio; + const Vector3DFloat v3dRayStart = v3dStart + v3dJitter; + + Vector3DFloat v3dRayDirection = randomUnitVectors[(mRandomUnitVectorIndex += (++mIndexIncreament)) % 1021]; //Differenct prime number. + v3dRayDirection *= m_fRayLength; + + /*raycast.setStart(v3dRayStart); + raycast.setDirection(v3dRayDirection); + raycast.execute(); + + if(raycastResult.foundIntersection == false) + { + ++uVisibleDirections; + }*/ + + MyRaycastResult result = raycastWithDirection(m_volInput, v3dRayStart, v3dRayDirection, AmbientOcclusionCalculatorRaycastCallback()); + if(result == MyRaycastResults::Completed) + { + ++uVisibleDirections; + } + } + + float fVisibility; + if(m_uNoOfSamplesPerOutputElement == 0) + { + //The user might request zero samples (I've done this in the past while debugging - I don't want to + //wait for ambient occlusion but I do want as valid result for rendering). Avoid the divide by zero. + fVisibility = 1.0f; + } + else + { + fVisibility = static_cast(uVisibleDirections) / static_cast(m_uNoOfSamplesPerOutputElement); + assert((fVisibility >= 0.0f) && (fVisibility <= 1.0f)); + } + + (*m_arrayResult)[z / iRatioZ][y / iRatioY][x / iRatioX] = static_cast(255.0f * fVisibility); + } + } + } + } } #include "PolyVoxCore/AmbientOcclusionCalculator.inl" diff --git a/tests/TestAmbientOcclusionGenerator.cpp b/tests/TestAmbientOcclusionGenerator.cpp index 7491f7c5..18402c96 100644 --- a/tests/TestAmbientOcclusionGenerator.cpp +++ b/tests/TestAmbientOcclusionGenerator.cpp @@ -61,11 +61,8 @@ void TestAmbientOcclusionGenerator::testExecute() const int32_t g_uArraySideLength = g_uVolumeSideLength / 2; Array<3, uint8_t> ambientOcclusionResult(ArraySizes(g_uArraySideLength)(g_uArraySideLength)(g_uArraySideLength)); - //Create the ambient occlusion calculator - AmbientOcclusionCalculator< SimpleVolume > calculator(&volData, &ambientOcclusionResult, volData.getEnclosingRegion(), 32.0f, 255, isVoxelTransparent); - - //Execute the calculator - calculator.execute(); + // Calculate the ambient occlusion values + calculateAmbientOcclusion(&volData, &ambientOcclusionResult, volData.getEnclosingRegion(), 32.0f, 255, isVoxelTransparent); //Check the results by sampling along a line though the centre of the volume. Because //of the two walls we added, samples in the middle are darker than those at the edge.