Trying to make my own blur shader, need some help with some basics.
TLDR: How do I return the ALBEDO of a FRAGCOORD? (I’ve googled this can’t find it anywhere)
Is it possible to affect fragments that are not part of the mesh the shader is attached to?
I noticed there is no Spatial Blur shader on Godot Shaders and I’ve been learning shaders for a week or so and decided to attempt to make one. My idea is the following:
Take each fragment, get the ALBEDO of it and every surrounding fragment, average them, then set the fragment ALBEDO to that average value.
This leads me to my first road block, I can get the surrounding FRAGCOORDs by adding/subtracting values from the fragments FRAGCOORD so that’s not a problem, but I don’t know how to get the ALBEDO of those surrounding FRAGCOORDS, which leads me to my first question:
How do I return the ALBEDO of a FRAGCOORD?
Another problem I’m foreseeing is when you blur something, the pixels on the edges will blur out into the background, like the following:
as you can see in the second, blurred image, the pixels of the object bleed out beyond the bounds of this object. If I made a shader for an object, how would I access those fragments to change their values? Is it even possible if theyre not part of the object the shader is attached to?
I’m not certain what you are trying to do here. If you want to blur the screen you need to do that as post processing effect, either with a viewport or a full screen quad. Both methods are covered in the documentation, there is even a blur shader example which should work fine for 3D you just do the processing in a viewport.
With regards to your question of how to your question about how to sample a fragcoord. If what you are sampling is the screen texture, you need a screen uv to sample it, so you can convert your fragcoord to a screen_uv coordinate by dividing with the VIEWPORT_SIZE.
Thanks for the help! What I’m trying to do is make a shader that blurs a specific object, so instead of covering the whole screen I could just blur a single object in the scene.
Blur would have to be applied in screenspace, so if you wanted just one object blurred you would have to render that separately, blur it and compose it into the scene.
I’m going to be very honest, I don’t understand any of what you just said but I do appreciate the help haha I’ll just keep plugging away at other stuff. Thanks again~
