Hey! I have texture mask, where I sample values from. It has 3 channels.
When I use default compresson setting. i.e. DXT1/BC1, compression is always DXT1
Bump. Wouldn’t BC1, with 1-bit alpha, be perfect for alpha-masked shaders (leaves, fences etc.)?
Of course, it is DXT1, because of confusing (no more) names of texture compressions. Here’s how they map:
| DXT | BCn |
|---|---|
| DXT1 | BC1 |
| DXT2 | BC2 with premultiplied Alpha |
| DXT3 | BC2 with explicit Alpha |
| DXT4 | BC3 withpremultiplied Alpha |
| DXT5 | BC3 with explicit Alpha |
| - | BC4 |
| - | BC5 |
If you choose “Default BC1 or BC3+A“ and your texture does not have Alpha channel, you get DXT1.
”Default BC1 or BC3+A” and your texture has Alpha chennel => you get DXT5.
”Masks (no sRGB)” and Compress Without Alpha = No => you get DXT1.
”Masks (no sRGB)” and Compres Without Alpha = Yes => you get DXT5.
For RGB-packed masks, I’d recommend using “Masks (no sRGB)“ which means DXT1 - which is perfect for VRAM efficiency. For more info, you can check my BCn Compression Guide