Initial commit for SER Sakura Scene with toggle

[chauvuha]

Implemented a more diverse scene that demonstrates the integration of Shader Execution Reordering (SER) to showcase performance gains:

• Included more varied materials: materialID == 1 triggers reflection rays, materialID == 2 and 3 sample from textures, and materialID == 0 uses a plain color.
• Separated closesthit shader for each material.
• Added three SER toggles: sort by HitObject, sort by materialID (from the shader table), and a combined mode using both.
• Toggle 'R' to turn on/off camera rotation (Note: Turn off rotation for better perf difference).

[Copilot]

Pull Request Overview

This PR introduces a new D3D12 Raytracing sample (“Sakura Scene”) demonstrating Shader Execution Reordering (SER) with multiple materials and toggleable sorting modes.

• Adds a complete sample project (headers, source, shaders, build files) for the SER-enabled Sakura scene
• Enhances HLSL raygen and closest-hit shaders to separate materials and apply SER based on HitObject, materialID, or both
• Provides README updates with controls and usage instructions

Reviewed Changes

Copilot reviewed 26 out of 33 changed files in this pull request and generated no comments.

File	Description
stdafx.h	New precompiled header pulling in core and D3D12 dependencies for the sample
Raytracing.hlsl	Implements SER toggles and per-material closest-hit shaders for diverse materials
readme.md	Documents sample usage, UI controls, and command-line options

Comments suppressed due to low confidence (4)

Samples/Desktop/D3D12Raytracing/src/D3D12RaytracingSakuraScene/readme.md:22

• Add a line for the 'R' key since the sample description mentions toggling camera rotation (e.g., * R - toggles camera rotation on/off.).

* S - toggles shader execution reordering on/off.

Samples/Desktop/D3D12Raytracing/src/D3D12RaytracingSakuraScene/D3D12RaytracingSakuraScene.h:115

• [nitpick] Member variable m_ObjModelLoader uses an uppercase ‘O’ after the prefix; consider m_objModelLoader for consistency with other m_ members.

    ObjModelLoader m_ObjModelLoader;

Samples/Desktop/D3D12Raytracing/src/D3D12RaytracingSakuraScene/D3D12RaytracingSakuraScene.h:157

• [nitpick] The prefix tcube is inconsistent with transparentCube; consider renaming to c_transparentCubeClosestHitShaderName to match the hit-group constant.

    static const wchar_t* c_tcubeClosestHitShaderName;

Samples/Desktop/D3D12Raytracing/src/D3D12RaytracingSakuraScene/D3D12RaytracingSakuraScene.vcxproj.filters:62

• The project references CheckCast.h but this header is not added in the diff; remove the reference or include the missing file to avoid build errors.

    <ClInclude Include="CheckCast.h" />