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Using final KHR ray tracing extension: VK_KHR_acceleration_structure, VK_KHR_ray_tracing_pipeline and VK_KHR_ray_query

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mklefrancois 2020-11-23 11:33:51 +01:00
parent 7179569ec3
commit b26ff92473
80 changed files with 2446 additions and 2351 deletions
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30
docs/vkrt_tuto_manyhits.md.htm
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@ -218,11 +218,11 @@ The size of each group can be described as follows:
~~~~ C++
// Sizes
uint32_t rayGenSize = baseAlignment;
uint32_t missSize = baseAlignment;
uint32_t rayGenSize = groupSizeAligned;
uint32_t missSize = groupSizeAligned;
uint32_t hitSize =
ROUND_UP(groupHandleSize + static_cast<int>(sizeof(HitRecordBuffer)), baseAlignment);
uint32_t newSbtSize = rayGenSize + 2 * missSize + 2 * hitSize;
nvh::align_up(groupHandleSize + static_cast<int>(sizeof(HitRecordBuffer)), groupSizeAligned);
uint32_t newSbtSize = rayGenSize + 2 * missSize + 3 * hitSize;
~~~~
Then write the new SBT like this, where only Hit 1 has extra data.
@ -258,21 +258,23 @@ Then change the call to `m_alloc.createBuffer` to create the SBT buffer from `sb
m_rtSBTBuffer = m_alloc.createBuffer(cmdBuf, sbtBuffer, vk::BufferUsageFlagBits::eRayTracingKHR);
~~~~
Note: we are using this `define` for rounding up to the correct alignment
~~~~ C++
#ifndef ROUND_UP
#define ROUND_UP(v, powerOf2Alignment) (((v) + (powerOf2Alignment)-1) & ~((powerOf2Alignment)-1))
#endif
~~~~
## `raytrace`
Finally, since the size of the hit group is now larger than just the handle, we need to set the new value of the hit group stride in `HelloVulkan::raytrace`.
Finally, since the size of the hit group is now larger than just the handle,
we need to set the new value of the hit group stride in `HelloVulkan::raytrace`.
~~~~ C++
vk::DeviceSize hitGroupStride =
ROUND_UP(m_rtProperties.shaderGroupHandleSize + sizeof(HitRecordBuffer), progOffset);
vk::DeviceSize hitGroupSize =
nvh::align_up(m_rtProperties.shaderGroupHandleSize + sizeof(HitRecordBuffer),
m_rtProperties.shaderGroupBaseAlignment);
std::array<Stride, 4> strideAddresses{
Stride{sbtAddress + 0u * groupSize, groupStride, groupSize * 1}, // raygen
Stride{sbtAddress + 1u * groupSize, groupStride, groupSize * 2}, // miss
Stride{sbtAddress + 3u * groupSize, hitGroupSize, hitGroupSize * 3}, // hit
Stride{0u, 0u, 0u}}; // callable
~~~~
!!! Note: