Cascade shadows are exploding

[snow mica]

I'm trying to implement cascaded shadow maps, using this LearnOpenGL article as a base: https://learnopengl.com/Guest-Articles/2021/CSM.

However, my cascade implementation is completely broken, and I'm not sure what to look for to figure out why. I added a debug draw path that shows which cascade each pixel should be reading (red = first, green = second, blue = third, pink = fourth) and that part seems to be correct. It's probably something to do with the generation of the shadowmaps themselves but I'm not sure what it is

[frosty violet]

just describing what i see, but do you render the lowest quality into the biggest cascade and vice versa?

[hollow timber]

the black part seems like your near plane is too close and your texture isn't set to render white on the outside

or you're just selecting a cascade at the wrong index in your shader

[snow mica]

inverting the cascade seems to sort of fix it, though the first cascade is still always returning black

[snow mica]

currently my near clip is set to 0.1 and I have the sampler border color set to white so that shouldn't return black for out of bounds samples