OK, I didn't understand that, so there's a good chance I don't know what I'm doing. When I export the SplatType.bmp if the pixel uses a big tile (Green channel) then I just set the Red channel to zero and Blue channel to 255. Is the Red channel supposed to have something there in that case, say the last used small tile value?
as the shaders sample the splat texture the system does a linear interplate between the samples based on the pixel position it is drawing.
Consider the following 2 pixels and all the pixels in between.
Left side is on vertex 0 right side is on vertex 1
R is small type
G is big type
B is the blend factor
0 0.25 0.5 0.75 1.0
R 255 255 255 255 255
G 0 64 128 192 255
B 255 192 128 64 0
With these 2 pixels at 0.25 it would be mixing 75% of small type 15 with big type 25% big type 2 (small 0 - 15 & big 0 - 3)
so if you want a clean transition you need it set up with both big an small the same on both pixels and only the G channel changing
R 255 255 255 255 255
G 0 64 128 192 255
B 255 255 255 255 255
Now it will always be mixing small type 15 and big type 3 and the transition will be smooth.
This is not something I specifically do , it is how shaders work when sampling between pixels.
HiTech