So, I'm trying to make a stencil mask that would allow fog to be seen only when looking through the mask, however, the stencil buffer in urp 13 seems to be bugged. Either that or I don't know how to write shaders, here is the mask shader: https://paste.myst.rs/fzrh6xs3 and here the fog shader I want to mask out : https://paste.myst.rs/u8bnxei2
#Is the stencil buffer bugged in unity 2022.1?
mellow lantern
Forgot to mention, the fog is implemented as a custom post processing effect using a blit renderer feature
rocky olive
blit operations discard stencil buffer information afaik
but I don't know specifics of your situation. usually I find related information to issues like those on the unity forums, often from bgolus
mellow lantern
Then it must be because I use blit, I'm really still a beginner in writing shaders
rocky olive
what's your use case?
I found an article or two about this once but I can't find it now
mellow lantern
This is how my scene looks like and I want to make the fog visible only by looking through a plane. The readon fot that is because I would then discard the plane's pixels if they are above 0 in world space, esentially replicating a wateine effect
rocky olive
and where does the blit come into play? is it maybe possible to do the fog rendering before the blit?
maybe that's different in newer unity versions as you can specify channels for render textures (I think i have seen that)
but when I tried it, when you do the first image effect blit, the incoming texture will have the right stencil buffer, but the target texture that is blitted to doesn't have it anymore.
and as such, only the first incoming texture for the first blit would have the stencil information
mellow lantern
What I think I'm gonna do, is instead of the fog being an image effect, how about I use a fog plane, this way I would be able to clip it based on height and I'd need stencils anymore
As you said, it's probably because the texture blitted to doesn't have stencil buffer anymore
I'm really interested in learning more about graphics even though I am still in high school
rocky olive
oh nice
there are a few resources for learning (unity) shaders pinned in #old_shaders
you could do the fog plane testing purely in a single shader for the water for whatever element you wanna apply it on too,
but I feel like this will be more complex and possibly more expensive than a stencil based approach
mellow lantern
I actually tried with the fog plane method
Before the blit one, but I wanted it to affect the water too which is a transparent shader, seeing it didn't I gave up and tried using blit(since I can set the render event to after transparents)
rocky olive
ah hmmhh
I just found this
https://answers.unity.com/questions/621279/using-the-stencil-buffer-in-a-post-process.html
not sure, maybe that's useful ,maybe not
mellow lantern
Thanks