I came across a really basic render issue with substrate this morning, but can find no reference online to anything similar. It’s SO basic that I was sure this meant I made a stupid error somewhere - but I’ve re-created it in a fresh download of the ‘Electric Dreams’ project in 5.5, so it seems to be legit.
The issue:
Layered substrate slabs exhibit a black edge / halo at the layer boundary when lit only by a skylight.
Close up - it’s only 1 pixel wide whatever the distance from camera:
Even closer:
To replicate this:
- Create the simplest possible layered slab material - if it uses a ‘vertical’ layer blend, the black line appears on the outer edge of the boundary, if it’s a ‘horizontal’ blend, it’s on the inner edge, but still visible
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Create a new default level
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Turn the skylight to ‘specified cubemap’, and select the default epic courtyard HDRI
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Turn the directional light off
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Add a mesh to the default level, and assign the material. In this test case, I used the ‘Electric Dreams’ project - the mesh is ‘Rock_Formation_04’ and the mask texture is ‘T_NoiseMask_RGB’, but any mask or mesh shows the same thing.
Is there a magic CVAR I’m missing?