I´ve also posted this in the big substrate feedback thread, but feel like this is more of a separate question worthy thread, that can be easier found by others.
Pretty excited for the new substrate materials, we do a lot of medical animation and some features are direly missing, like rough refractions, as well es better mixing with SSS and other layers.
- Compatibility with Material Layer GUI based material layering.
I´m ALSO currently in the process of moving our current Material Attribute Blending based Master Blend Material to a Material Layer GUI based Material layer Blending workflow.
Unreal 5.7 is still in Preview and I´ve read the documentation for 5.6, but I´m not sure IF substrate material layers would work with the Material Layer GUI or HOW exactly it will still be limited in 5.7.
- Tanget normal maps
I also asked the dev AI about other current limitations and it mentioned tangent space normals not being fully supported in Substrate yet.
As at least one of my triplanar normal mapping functions I use rely on tangent space normal mapping, this would mean there still is NO parity with legacy materials.
Is this still being adressed in Unral 5.7.1 release? Or is it still a limitation?
Or is that just a limitation of the Material Layer GUI implementation for Substrate?
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Blending of translucent wih opaque SSS
I´m also not quite sure how limited this is, compared to legacy materials.
In legacy materials, you could only blend opaque materials with translucent materials by setting opacity values from 0-1.
There was no way to do this with a subsurface profile based material.
Is this now somehow possible, as you would use the MFP for both SSS AND translucency control in the new substrate slabs?
I only read that “Screen space SSS” isn´t supported, but would I still be able to blend opaque SSS material with a translucent material using raytraced SSS with Lumen/Path tracing? -
Issues with pixel/vertex shader nodes?
I use a custom triplanar mapping function for making triplanar mapping sticky on skeletal meshes.
It relies some nodes like “vertex interpolator” and “pre skinned normal”, that are currently not compatible with the Material Layer GUI.
Are there also any limitations related to Substrate with how this would work, or is that just something that I´d have to deal with for Material Layer GUI based material layering?
And any idea if that is something, that is being worked on currently?
Because its rather relevant to my decision to move to the Material Layer GUI, because if that isn´t adressed, I have to either stick with the old material attribute layering or maintain TWO Master Materials (one for skeletal meshes and material attribute blending, one for the Material Layer GUI System)