ND_surface should have color opacity
code-monkey opened this issue · 1 comments
code-monkey commented
Currently opacity is defined as a float
in ND_surface
. There are many use cases (stained glass) where it would be good to have opacity defined as a color3
.
There's even a documented work-around in standard_surface.mtlx
to convert the incoming color to a scalar value. Full color opacity is needed to reproduce the standard surface faithfully.
<!-- Surface construction with opacity -->
<!-- Node <surface> only supports monochromatic opacity so use the luminance of input opacity color -->
<luminance name="opacity_luminance" type="color3">
It's easy to get a scalar value out of a color, it's not possible to get a color out of a scalar.
niklasharrysson commented
Hi Mark,
Thanks for reporting this! I will create an issue for this on the MaterialX github, since it's a limitation in the MaterialX spec. rather than a limitation with the Standard Surface specification. And we can continue the discussion there.