procedural-3d-engine/data/hlsl/README.md

HLSL Shaders

This directory contains a fork of the shaders found in data/shaders, re-written in HLSL. These can be compiled with DXC using the compile.py script.

Status

Tested on Ubuntu 18.04 + GeForce RTX 2080 Ti

Shaders written to mirror the GLSL versions at eddd724. There have been changes made to the GLSL shaders since then, which will need to be updated.

Name	GLSL @eddd724e7	HLSL @eddd724e7	GLSL @10a1ecaf7	HLSL @eddd724e7
bloom	☑	☑	☑	☑
computecloth	☑	☑	☑	☑
computecullandlod	☑	☑	☑	☑
computeheadless	☑	☑	☑	☑
computenbody	☑	☑	☑	☑
computeparticles	☑	❌	☑	❌
computeraytracing	☑	☑	☑	☑
computeshader	☑	☑	☑	☑
conditionalrender	☑	☑	☑	☑
conservativeraster	☑	☑	☑	☑
debugmarker	☑	☑	☑	☑
deferred	☑	☑	☑	☑
deferredmultisampling	☑	☑	☑	☑
deferredshadows	☑	☑	☑	☑
descriptorsets	☑	☑	☑	☑
displacement	☑	☑	☑	☑
distancefieldfonts	☑	☑	☑	☑
dynamicuniformbuffer	☑	☑	☑	☑
gears	☑	☑	☑	☑
geometryshader	☑	☑	☑	☑
gltfscene	-	-	☑	❌
hdr	☑	❌	☑	❌
imgui	☑	☑	☑	☑
indirectdraw	☑	☑	☑	☑
inlineuniformblocks	☑	☑	☑	☑
inputattachments	☑	☑	☑	☑
instancing	☑	☑	☑	☑
mesh	☑	☑	❌	☑
multisampling	☑	☑	☑	❌
multithreading	☑	☑	☑	☑
multiview	☑	☑	☑	☑
negativeviewportheight	☑	☑	☑	☑
nv_ray_tracing_basic	☑	☑	☑	☑
nv_ray_tracing_reflections	☑	☑	☑	☑
nv_ray_tracing_shadows	☑	☑	☑	☑
occlusionquery	☑	☑	☑	☑
offscreen	☑	☑	☑	❌
parallaxmapping	☑	☑	☑	☑
particlefire	☑	☑	☑	☑
pbrbasic	☑	☑	☑	☑
pbribl	☑	☑	☑	☑
pbrtexture	☑	☑	☑	☑
pipelines	☑	☑	☑	☑
pipelinestatistics	☑	☑	☑	☑
pushconstants	☑	☑	☑	☑
pushdescriptors	☑	☑	☑	☑
radialblur	☑	☑	☑	☑
renderheadless	☑	☑	☑	☑
scenerendering	☑	☑	☑	☑
screenshot	☑	☑	☑	☑
shadowmapping	☑	☑	☑	☑
shadowmappingcascade	☑	☑	☑	☑
shadowmappingomni	☑	☑	☑	☑
skeletalanimation	☑	☑	☑	❌
specializationconstants	☑	☑	☑	☑
sphericalenvmapping	☑	☑	☑	☑
ssao	☑	☑	☑	☑
stencilbuffer	☑	☑	☑	☑
subpasses	☑	☑	☑	☑
terraintessellation	☑	☑	☑	☑
tessellation	☑	☑	☑	☑
textoverlay	☑	☑	☑	☑
texture	☑	☑	☑	☑
texture3d	☑	☑	☑	☑
texturearray	☑	☑	☑	☑
texturecubemap	☑	❌	☑	❌
texturemipmapgen	☑	☑	☑	☑
texturesparseresidency	☑	☑	☑	☑
triangle	☑	☑	☑	☑
viewportarray	☑	☑	☑	☑
vulkanscene	☑	☑	☑	☑

Known issues

• specialization constants can't be used to specify array size.
• gl_PointCoord not supported. HLSL has no equivalent. We changed the shaders to calulate the PointCoord manually in the shader. (computenbody, computeparticles, particlefire examples).
• HLSL doesn't have inverse operation (deferred, hdr, instancing, skeletalanimation & texturecubemap examples).
• modf causes compilation to fail without errors or warnings. (modf not used by any examples, easily confused with fmod)
• In specializationconstants example, shader compilation fails with error:

  --- Error msg: fatal error: failed to optimize SPIR-V: Id 10 is defined more than once
  

  When multiple constant ids are defined and have different types. We work around this problem by making all constant ids the same type, then use asfloat, asint or asuint to get the original value in the shader.
• gl_RayTmaxNV not supported. (nv_ray_tracing_* examples)
• HLSL interface for sparse residency textures is different from GLSL interface. After translating from HLSL to GLSL the shaders behave slightly different. Most important parts do behave identically though.