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Cached BLAS objects at the sub-mesh level

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Signed-off-by: dmcdiar <dmcdiar@amazon.com>
This commit is contained in:
dmcdiar
2021-09-23 13:49:10 -07:00
parent 2ef5a6453e
commit 2dc7b517d1
2 changed files with 38 additions and 19 deletions
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Gems/Atom/Feature/Common/Code/Source/RayTracing/RayTracingFeatureProcessor.cpp
+29 -15
View File
@@ -105,14 +105,31 @@ namespace AZ
m_meshes[objectIndex].m_subMeshes = subMeshes;
}
Mesh& mesh = m_meshes[objectIndex];
// search for an existing BLAS instance entry for this mesh using the assetId
BlasInstanceMap::iterator itMeshBlasInstance = m_blasInstanceMap.find(assetId);
if (itMeshBlasInstance == m_blasInstanceMap.end())
{
// make a new BLAS map entry for this mesh
MeshBlasInstance meshBlasInstance;
meshBlasInstance.m_count = 1;
meshBlasInstance.m_subMeshes.reserve(mesh.m_subMeshes.size());
itMeshBlasInstance = m_blasInstanceMap.insert({ assetId, meshBlasInstance }).first;
}
else
{
itMeshBlasInstance->second.m_count++;
}
// create the BLAS buffers for each sub-mesh, or re-use existing BLAS objects if they were already created.
// Note: all sub-meshes must either create new BLAS objects or re-use existing ones, otherwise it's an error (it's the same model in both cases)
// Note: the buffer is just reserved here, the BLAS is built in the RayTracingAccelerationStructurePass
Mesh& mesh = m_meshes[objectIndex];
bool blasInstanceFound = false;
for (auto& subMesh : mesh.m_subMeshes)
for (uint32_t subMeshIndex = 0; subMeshIndex < mesh.m_subMeshes.size(); ++subMeshIndex)
{
SubMesh& subMesh = mesh.m_subMeshes[subMeshIndex];
RHI::RayTracingBlasDescriptor blasDescriptor;
blasDescriptor.Build()
->Geometry()
@@ -121,13 +138,11 @@ namespace AZ
->IndexBuffer(subMesh.m_indexBufferView)
;
// search for an existing BLAS object for this model
RayTracingBlasMap::iterator itBlas = m_blasMap.find(assetId);
if (itBlas != m_blasMap.end())
// determine if we have an existing BLAS object for this subMesh
if (itMeshBlasInstance->second.m_subMeshes.size() >= subMeshIndex + 1)
{
// re-use existing BLAS
subMesh.m_blas = itBlas->second.m_blas;
itBlas->second.m_count++;
subMesh.m_blas = itMeshBlasInstance->second.m_subMeshes[subMeshIndex].m_blas;
// keep track of the fact that we re-used a BLAS
blasInstanceFound = true;
@@ -143,8 +158,7 @@ namespace AZ
subMesh.m_blas->CreateBuffers(*device, &blasDescriptor, *m_bufferPools);
// store the BLAS in the side list
RayTracingBlasInstance blasInstance = { subMesh.m_blas, 1 };
m_blasMap.insert({ assetId, blasInstance });
itMeshBlasInstance->second.m_subMeshes.push_back({ subMesh.m_blas });
}
}
@@ -182,16 +196,16 @@ namespace AZ
m_meshes.erase(itMesh);
m_revision++;
// decrement the count from the BLAS instance, and check to see if we can remove it
RayTracingBlasMap::iterator itBlas = m_blasMap.find(itMesh->second.m_assetId);
if (itBlas != m_blasMap.end())
// decrement the count from the BLAS instances, and check to see if we can remove them
BlasInstanceMap::iterator itBlas = m_blasInstanceMap.find(itMesh->second.m_assetId);
if (itBlas != m_blasInstanceMap.end())
{
itBlas->second.m_count--;
if (itBlas->second.m_count == 0)
{
m_blasMap.erase(itBlas);
m_blasInstanceMap.erase(itBlas);
}
}
}
}
m_meshInfoBufferNeedsUpdate = true;
Gems/Atom/Feature/Common/Code/Source/RayTracing/RayTracingFeatureProcessor.h
+9 -4
View File
@@ -268,14 +268,19 @@ namespace AZ
bool m_materialInfoBufferNeedsUpdate = false;
// side list for looking up existing BLAS objects so they can be re-used when the same mesh is added multiple times
struct RayTracingBlasInstance
struct SubMeshBlasInstance
{
RHI::Ptr<RHI::RayTracingBlas> m_blas;
uint32_t m_count = 0;
};
using RayTracingBlasMap = AZStd::unordered_map<AZ::Data::AssetId, RayTracingBlasInstance>;
RayTracingBlasMap m_blasMap;
struct MeshBlasInstance
{
uint32_t m_count = 0;
AZStd::vector<SubMeshBlasInstance> m_subMeshes;
};
using BlasInstanceMap = AZStd::unordered_map<AZ::Data::AssetId, MeshBlasInstance>;
BlasInstanceMap m_blasInstanceMap;
};
}
}