[4.15 p2] MSAA and Alpha2Coverage problem

Development Rendering
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7

Also, here is the simple workaround. A function change in MaterialTemplate.usf . Line 1739 .

uint DiscardMaterialWithPixelCoverage(FMaterialPixelParameters MaterialParameters, FPixelMaterialInputs PixelMaterialInputs)
    {
    	ClipLODTransition(MaterialParameters);
    	float OriginalMask = GetMaterialMaskInputRaw(PixelMaterialInputs);
    	float MaskClip = GetMaterialOpacityMaskClipValue();
    
    	if (View.NumSceneColorMSAASamples > 1)
    	{
    		MaskClip = MaskClip * 0.05; //Workaround for Alpha2Coverage
    		
    		float Mask = (OriginalMask - MaskClip) / (1.0 - MaskClip);
    		uint CurrentPixelCoverage = GetDerivativeCoverageFromMask(Mask);

    		clip(float(CurrentPixelCoverage) - 0.5);
    		return CurrentPixelCoverage;
    	}
    	clip(OriginalMask - MaskClip);
    	return 0xF;
    }