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Fix brute force mesh intersection function (#5447)

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* fix brute force mesh intersection function

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>

* add test for brute force ray intersection fix

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>

* refactor tests to remove as much duplication and provide API for future tests if required

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>

* small updates after review feedback

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>

* update following review feedback

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>

* fix for pointer offset

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>
This commit is contained in:
Tom Hulton-Harrop
2021-11-11 16:33:08 +00:00
committed by GitHub
parent 6e70097ad7
commit 2812ec2024
5 changed files with 178 additions and 63 deletions
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Gems/Atom/RPI/Code/Source/RPI.Reflect/Model/ModelAsset.cpp
+25 -31
View File
@@ -201,23 +201,11 @@ namespace AZ
AZ::Vector3& normal) const
{
const BufferAssetView& indexBufferView = mesh.GetIndexBufferAssetView();
const AZStd::array_view<ModelLodAsset::Mesh::StreamBufferInfo>& streamBufferList = mesh.GetStreamBufferInfoList();
const BufferAssetView* positionBufferView = mesh.GetSemanticBufferAssetView(m_positionName);
// find position semantic
const ModelLodAsset::Mesh::StreamBufferInfo* positionBuffer = nullptr;
for (const ModelLodAsset::Mesh::StreamBufferInfo& bufferInfo : streamBufferList)
if (positionBufferView && positionBufferView->GetBufferAsset().Get())
{
if (bufferInfo.m_semantic.m_name == m_positionName)
{
positionBuffer = &bufferInfo;
break;
}
}
if (positionBuffer && positionBuffer->m_bufferAssetView.GetBufferAsset().Get())
{
BufferAsset* bufferAssetViewPtr = positionBuffer->m_bufferAssetView.GetBufferAsset().Get();
BufferAsset* bufferAssetViewPtr = positionBufferView->GetBufferAsset().Get();
BufferAsset* indexAssetViewPtr = indexBufferView.GetBufferAsset().Get();
if (!bufferAssetViewPtr || !indexAssetViewPtr)
@@ -225,7 +213,7 @@ namespace AZ
return false;
}
RHI::BufferViewDescriptor positionBufferViewDesc = bufferAssetViewPtr->GetBufferViewDescriptor();
RHI::BufferViewDescriptor positionBufferViewDesc = positionBufferView->GetBufferViewDescriptor();
AZStd::array_view<uint8_t> positionRawBuffer = bufferAssetViewPtr->GetBuffer();
const uint32_t positionElementSize = positionBufferViewDesc.m_elementSize;
@@ -234,22 +222,28 @@ namespace AZ
// Position is 3 floats
if (positionElementSize != sizeof(float) * 3)
{
AZ_Warning("ModelAsset", false, "unsupported mesh posiiton format, only full 3 floats per vertex are supported at the moment");
AZ_Warning(
"ModelAsset", false, "unsupported mesh posiiton format, only full 3 floats per vertex are supported at the moment");
return false;
}
RHI::BufferViewDescriptor indexBufferViewDesc = indexBufferView.GetBufferViewDescriptor();
AZStd::array_view<uint8_t> indexRawBuffer = indexAssetViewPtr->GetBuffer();
RHI::BufferViewDescriptor indexRawDesc = indexAssetViewPtr->GetBufferViewDescriptor();
bool anyHit = false;
const AZ::Vector3 rayEnd = rayStart + rayDir;
AZ::Vector3 a, b, c;
AZ::Vector3 intersectionNormal;
bool anyHit = false;
float shortestDistanceNormalized = AZStd::numeric_limits<float>::max();
const AZ::u32* indexPtr = reinterpret_cast<const AZ::u32*>(indexRawBuffer.data());
for (uint32_t indexIter = 0; indexIter <= indexRawDesc.m_elementCount - 3; indexIter += 3, indexPtr += 3)
const AZ::u32* indexPtr = reinterpret_cast<const AZ::u32*>(
indexRawBuffer.data() + (indexBufferViewDesc.m_elementOffset * indexBufferViewDesc.m_elementSize));
const float* positionPtr = reinterpret_cast<const float*>(
positionRawBuffer.data() + (positionBufferViewDesc.m_elementOffset * positionBufferViewDesc.m_elementSize));
constexpr int StepSize = 3; // number of values per vertex (x, y, z)
for (uint32_t indexIter = 0; indexIter < indexBufferViewDesc.m_elementCount; indexIter += StepSize, indexPtr += StepSize)
{
AZ::u32 index0 = indexPtr[0];
AZ::u32 index1 = indexPtr[1];
@@ -261,17 +255,17 @@ namespace AZ
return false;
}
const float* p = reinterpret_cast<const float*>(&positionRawBuffer[index0 * positionElementSize]);
a.Set(const_cast<float*>(p)); // faster than AZ::Vector3 c-tor
p = reinterpret_cast<const float*>(&positionRawBuffer[index1 * positionElementSize]);
b.Set(const_cast<float*>(p));
p = reinterpret_cast<const float*>(&positionRawBuffer[index2 * positionElementSize]);
c.Set(const_cast<float*>(p));
// faster than AZ::Vector3 c-tor
const float* aRef = &positionPtr[index0 * StepSize];
a.Set(aRef);
const float* bRef = &positionPtr[index1 * StepSize];
b.Set(bRef);
const float* cRef = &positionPtr[index2 * StepSize];
c.Set(cRef);
float currentDistanceNormalized;
if (AZ::Intersect::IntersectSegmentTriangleCCW(rayStart, rayEnd, a, b, c, intersectionNormal, currentDistanceNormalized))
if (AZ::Intersect::IntersectSegmentTriangleCCW(
rayStart, rayEnd, a, b, c, intersectionNormal, currentDistanceNormalized))
{
anyHit = true;