Specular aliasing and Normal to Roughness

[sealfoss]

Thanks for the info!

Valve mentions a solution for specular aliasing as:

Here’s a trick we are using:
● Interpolate normal twice: once with centroid, once without
float3 vNormalWs : TEXCOORD0;
centroid float3 vCentroidNormalWs : TEXCOORD1;
● In the pixel shader, choose the centroid normal if normal length squared is
greater than 1.01
if ( dot( i.vNormalWs.xyz, i.vNormalWs.xyz ) >= 1.01 )
{
i.vNormalWs.xyz = i.vCentroidNormalWs.xyz;
}

But the release announcement for 4.14 makes it seem like a solution has already been implemented by Epic, with:

Projects that choose to use MSAA will want to build content to mitigate specular aliasing. The ‘Normal to Roughness’ feature can help reduce specular aliasing from detailed normal maps.

So am I reading into that more than I should be?