Unreal Engine Issues and Bug Tracker (UE-92949)

Description

This appears to be new in 4.25.

Steps to Reproduce

Create a new material
Set the blend mode to Translucent
Add a "SpiralBlur-SceneTexture" node to the graph
Connect a constant value of 1 to Distance, Distance Steps, and Radial Steps
Connect the Result output pin to the Emissive input
Compile the material
Observe numerous "warning: implicit truncation of vector type" errors

Callstack

[SM5] at 0x1dea5421420 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
 Validation failed.
 D3DCompileToDxil failed
[SM5] /Engine/Generated/Material.ush(1864:13): warning: implicit truncation of vector type
 RandomSamp+=Texture2DSample(Tex,TexSampler,ScenePixels);
 ^
[SM5] /Engine/Generated/Material.ush(1867:17): warning: implicit truncation of vector type
 TempAARotation*=RandomSamp;
 ^
[SM5] /Engine/Generated/Material.ush(1868:25): warning: implicit truncation of vector type
 TempAADistance*=StepSize*RandomSamp;
 ^
[SM5] /Engine/Generated/Material.ush(1888:9): warning: implicit truncation of vector type
 NewUV.x = BaseUV.x + (CurOffset.x * (CurDistance+(RandomSamp*TempAADistance)));
 ^
[SM5] /Engine/Generated/Material.ush(1889:9): warning: implicit truncation of vector type
 NewUV.y = BaseUV.y + (CurOffset.y * (CurDistance+(RandomSamp*TempAADistance)));
 ^
[SM5] error: validation errors 
 at 0x210624c3e20 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
 at 0x210624c3ba0 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
[SM5] at 0x210624c3c20 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
 at 0x210624c50a0 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
 at 0x210624c4720 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
[SM5] at 0x210624c5120 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
 Validation failed.
 D3DCompileToDxil failed
[SM5] error: validation errors 
 at 0x1dea5421d20 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
 at 0x1dea5421520 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
[SM5] at 0x1dea5421ea0 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
 at 0x1dea54211a0 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value
 at 0x1dea54212a0 inside block ?internal.CalcInterpolants@@YAXUFRayCone@@UFDefaultAttributes@@UFVertexFactoryInterpolantsVSToPS@@@Z.exit of function ?MaterialCHS@@YAXUFPackedMaterialClosestHitPayload@@UFDefaultAttributes@@@Z Instructions should not read uninitialized value

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Fixed

Component	UE - Graphics Features
Affects Versions	4.25, 4.26
Target Fix	4.26

Fix Commit	14560985
Release Commit	14560985

Created	May 8, 2020
Resolved	Oct 23, 2020
Updated	Sep 19, 2021

UE-92949

Use of SpiralBlur-SceneTexture MaterialFunction in translucent material results in compile errors

Use of SpiralBlur-SceneTexture MaterialFunction in translucent material results in compile errors

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