1bit per channel splat texture ?

Unity Engine
1

Hi all :slight_smile:

does anyone know wether or not it would be possible to ha a 4 bits ( 1 bit for each RGBA channel ) ) splat texture, for modulating 4 textures blending ?

I know the base answer would be ‘yes’ :wink: but am not sure wether it still is on GPUs…

And if yes, how could this be achievable in unity ?

hoping for shader writers answers :smile:

best regards and happy unitying !!!

2

Sure. Totally possible… by using a single channel of a RGBA4444 texture using point sampling and bit packing! … or you know, just use the 4 channels the texture already has.

If you want to use less than 16 bits, you can get down to 8 bits by using an R8 or A8 using point sampling and bit packing.

Otherwise, no. GPUs do not support any kind of 1 bit per channel* or single channel 4 bit formats.

  • DXT1A is a now esoteric version of DXT1 with a 1 bit alpha that GPUs still support, but which Unity has never supported. Render textures can also use a RGBA5551 packed format, but that means uploading the data in another format. They both also have 4 channels of data which have 5 bits of color precision each (DXT1 normally stores colors in 565 palettes, but uses a 5551 palette in DXT1A mode) making the whole thing moot. Just use an RGBA4444.
1 Like