Basically, I’m having trouble getting the alpha channel from my attribute map texture.
I’m using the SetAlphaFromMap block (in the initialize context)… but it seems to use the Red channel of the attribute map’s texture, rather than the Alpha channel. How can I make it such that it uses the Alpha channel instead?
Attempted workarounds: I’ve tried to use my own “spawnIndex to UV” functions to generate an input for the SampleTexture block, so I could PICK the channel to use… but I kept running into weird problems. A reference to a known good one would be a good workaround for this question!
Details of what I have:
Here is the simple diagram of the current VFX graph. (which doesn’t work exactly right- positioning is great, but alpha is based on R, rather than A).
The input texture “PosTex” holds the XYZ of a normalized direction vector in the RGB channels, and another value, “brightness”, in the A channel. For testing though, I just set this A value to 0.5f for each pixel of the texture.
As you can see in this shot of the output… the alpha has the same value as (pre-bias)X, not the 0.5f I put in as a test.
