Ethatron/nifopt — Issue #1: DXT1 is special for Gamebryo
Author: Ethatron
Created: 2011-12-09 11:11:01+00:00
State: open

If a NIF defines transparency for the color DDS (for parallax mapping it's irrelevant which uni-color the alpha-channel has, it's all flat and can be stripped), then it is not allowed to use DXT1, because then transparency is turned off - the same way specular is turned off when the normal-maps are DXT1.

1bit alpha-channels thus can NOT be cnverted to DXT1 because it means no alpha-channel to Gamebryo.

It would mean I have to convert to DXT1 for normals only if the alpha-channel is black, not when it's black & white.
It would mean I have to convert to DXT1 for colors only if the alpha-channel is white, not when it's black & white.

Later for the DB-based version we can convert uni-color spec alpha to a NIF-attribute.
Later for the DB-based version we can convert uni-color trans alpha to a NIF-attribute.