Description

We should get to the bottom of this workaround and revert it eventually. 

Reported here: [Link Removed] 

Steps to Reproduce

In some cases, having a vertically layered material will show significant performance regression caused by Substrate.ush defining UNROLL as LOOP.

 

// DXC has issue with unrolling certain part of the code. To address temporarly the warning-as-error issues, 
// we redefine the unroll function and fall back to loop on DXC
// To remove this, one must test PC + DX12 + RayTracing and make sure raytracing shaders compile.
#define SUBSTRATE_COMPILER (COMPILER_VULKAN)
#if SUBSTRATE_COMPILER == 1
#define SUBSTRATE_UNROLL LOOP
#define SUBSTRATE_UNROLL_N(X) LOOP
#else
#define SUBSTRATE_UNROLL UNROLL
#define SUBSTRATE_UNROLL_N(X) UNROLL_N(X)
#endif 

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Unresolved
ComponentUE - Graphics Features - Substrate
Affects Versions5.45.3
Target Fix5.6
CreatedApr 8, 2024
UpdatedSep 19, 2024
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