The current compressor struggles to compress hard edges in images with fast transparency changes when the backing RGB color in the transparent region is totally different to the non-transparent color (e.g. black). This can cause block artifacts along the transparent edges in the image.
The usual fix for this is to extrude the non-transparent edge color in to the transparent region, minimizing the magnitude of the color diff that must be represented. The current compressor requires users to manually pre-extrude their textures prior to compression, which many DCC tools can do, but we can probably do something specifically format-aware based on e.g. choosing a current partition endpoint color or the average of them.
We could do this automatically when using the -a option, but should also add an explicit enable/disable flag so users can control whether this optimization is applied.
The current compressor struggles to compress hard edges in images with fast transparency changes when the backing RGB color in the transparent region is totally different to the non-transparent color (e.g. black). This can cause block artifacts along the transparent edges in the image.
The usual fix for this is to extrude the non-transparent edge color in to the transparent region, minimizing the magnitude of the color diff that must be represented. The current compressor requires users to manually pre-extrude their textures prior to compression, which many DCC tools can do, but we can probably do something specifically format-aware based on e.g. choosing a current partition endpoint color or the average of them.
We could do this automatically when using the
-aoption, but should also add an explicit enable/disable flag so users can control whether this optimization is applied.