D3D12_RAYTRACING_GEOMETRY_DESC geometryDesc = {};
geometryDesc.Type = D3D12_RAYTRACING_GEOMETRY_TYPE_TRIANGLES;
geometryDesc.Triangles.IndexBuffer = 0;// GPU-address index-буфера (здесь не используем)
geometryDesc.Triangles.IndexCount = 0;
geometryDesc.Triangles.IndexFormat = 0;// например DXGI_FORMAT_R16_UINT;
geometryDesc.Triangles.VertexFormat = DXGI_FORMAT_R32G32B32_FLOAT;
geometryDesc.Triangles.VertexCount = <количество вершин>;
geometryDesc.Triangles.VertexBuffer.StartAddress = <GPU-address вершинного буфера>;
geometryDesc.Triangles.VertexBuffer.StrideInBytes = sizeof(Vertex);

D3D12_BUILD_RAYTRACING_ACCELERATION_STRUCTURE_INPUTS bottomLevelInputs;
bottomLevelInputs.DescsLayout = D3D12_ELEMENTS_LAYOUT_ARRAY;
bottomLevelInputs.Flags = D3D12_RAYTRACING_ACCELERATION_STRUCTURE_BUILD_FLAG_PREFER_FAST_TRACE;
bottomLevelInputs.Type = D3D12_RAYTRACING_ACCELERATION_STRUCTURE_TYPE_BOTTOM_LEVEL;
bottomLevelInputs.pGeometryDescs = &geometryDesc;
bottomLevelInputs.NumDescs = 1;
D3D12_BUILD_RAYTRACING_ACCELERATION_STRUCTURE_DESC bottomLevelBuildDesc = {};
bottomLevelBuildDesc.Inputs = bottomLevelInputs;
bottomLevelBuildDesc.ScratchAccelerationStructureData = scratchResource->GetGPUVirtualAddress();
bottomLevelBuildDesc.DestAccelerationStructureData = bottomLevelAccelerationStructure->GetGPUVirtualAddress(); // ID3D12Resource* bottomLevelAccelerationStructure - аллоцированный буфер необходимого размера

dxrCommandList->BuildRaytracingAccelerationStructure(&bottomLevelBuildDesc, 0, nullptr);

D3D12_RAYTRACING_INSTANCE_DESC instanceDesc[2] = {};
    for (int i = 0; i < 2; ++i)
    {
        instanceDesc[i].Transform = YourEngineTransformToDXR(transforms[i]);
        instanceDesc[i].InstanceMask = 1;
        instanceDesc[i].InstanceID = 0; // не используем
        instanceDesc[i].InstanceContributionToHitGroupIndex = i; // отвечает за смещение в hit SBT
        instanceDesc[i].AccelerationStructure = bottomLevelAccelerationStructure->GetGPUVirtualAddress();
    }

ComPtr<ID3D12StateObjectProperties> stateObjectProperties;
dxrStateObject.As(&stateObjectProperties);
void* rayGenShaderIdentifier = stateObjectProperties->GetShaderIdentifier(L"RayGen");

#include "Common.hlsl"
#include "Global.hlsl"
struct CameraData
{
    float4 forward;
    float4 right;
    float4 up;
    float4 origin;
};
ConstantBuffer<CameraData> gCamera : register(b0);
[shader("raygeneration")]
void RayGen()
{
    HitInfo payload;
    payload.colorAndDistance = float4(0, 0, 0, 0);
    uint2 launchIndex = DispatchRaysIndex().xy;
    float2 dims = float2(DispatchRaysDimensions().xy);
    float2 ndc = float2(
        float(launchIndex.x + 0.5f) / dims.x * 2 - 1,
        float(dims.y - launchIndex.y - 1 + 0.5) / dims.y * 2 - 1);
    RayDesc ray;
    ray.Origin = gCamera.origin.xyz;
    ray.Direction = GetWorldRay(ndc, gCamera.forward.xyz, gCamera.right.xyz, gCamera.up.xyz);
    ray.TMin = 0;
    ray.TMax = 100000;
    TraceRay(
        SceneBVH,
        RAY_FLAG_NONE,
        0xFF,
        0, // RayContributionToHitGroupIndex
        0, // MultiplierForGeometryContributionToHitGroupIndex
        0, // MissShaderIndex
        ray,
        payload);
    gOutput[launchIndex] = float4(payload.colorAndDistance.rgb, 1.f);
}

#include "Common.hlsl"
#include "Global.hlsl"
struct InstanceData
{
    float4 color;
};
ConstantBuffer<InstanceData> instanceData : register(b1);
[shader("closesthit")]
void ClosestHit(inout HitInfo payload, Attributes attrib)
{
    float3 barycentrics = float3(1.f - attrib.bary.x - attrib.bary.y, attrib.bary.x, attrib.bary.y);
    float3 vertexNormals[3] = {
        Vertices[PrimitiveIndex() * 3].normal,
        Vertices[PrimitiveIndex() * 3 + 1].normal,
        Vertices[PrimitiveIndex() * 3 + 2].normal
    };
    float3 N = vertexNormals[0] * barycentrics.x +
        vertexNormals[1] * barycentrics.y +
        vertexNormals[2] * barycentrics.z;
    const float3 L = normalize(float3(0, -0.4, 1));
    payload.colorAndDistance = float4(instanceData.color.rgb * max(0, dot(N, L)), RayTCurrent());
}

#include "Common.hlsl"
[shader("miss")]
void Miss(inout HitInfo payload : SV_RayPayload)
{
    payload.colorAndDistance = float4(0.0f, 0.2f, 0.7f, -1.0f);
}

//...
// Устанавливаем глобальную root signature
dxrCommandList->SetComputeRootSignature(raytracingGlobalRootSignature.Get());
// прикрепляем основной descriptor heap
dxrCommandList->SetDescriptorHeaps(1, descriptorHeap.GetAddressOf());
// устанавливаем глобальные ресурсы
dxrCommandList->SetComputeRootDescriptorTable(0, raytracingOutputResourceUAVGpuDescriptor);
dxrCommandList->SetComputeRootDescriptorTable(1, buffersGpuDescriptor);
dxrCommandList->SetComputeRootShaderResourceView(2, topLevelAccelerationStructure->GetGPUVirtualAddress());
// устанавливаем данные камеры
//...
D3D12_DISPATCH_RAYS_DESC dispatchDesc = {};
dispatchDesc.HitGroupTable.StartAddress = hitGroupShaderTable->GetGPUVirtualAddress();
dispatchDesc.HitGroupTable.SizeInBytes = hitGroupShaderTable->GetDesc().Width;
dispatchDesc.HitGroupTable.StrideInBytes = 64; // размер hit shader record
dispatchDesc.MissShaderTable.StartAddress = missShaderTable->GetGPUVirtualAddress();
dispatchDesc.MissShaderTable.SizeInBytes = missShaderTable->GetDesc().Width;
dispatchDesc.MissShaderTable.StrideInBytes = dispatchDesc.MissShaderTable.SizeInBytes;
dispatchDesc.RayGenerationShaderRecord.StartAddress = rayGenShaderTable->GetGPUVirtualAddress();
dispatchDesc.RayGenerationShaderRecord.SizeInBytes = rayGenShaderTable->GetDesc().Width;
dispatchDesc.Width = width;
dispatchDesc.Height = height;
dispatchDesc.Depth = 1;
dxrCommandList->SetPipelineState1(dxrStateObject.Get());
dxrCommandList->DispatchRays(&dispatchDesc);
//...