Question Shadow depth not applied in custom lit shader

Hi! I'm experimenting with some stylized shaders for a project and am currently working on receiving shadows in a custom shader. Unfortunately, I'm getting what looks like (though I could be wrong) self-shadow artifacts as if the shadow depth isn't being taken into consideration when sampling. I'm brand new to working with shaders in URP, so I may be missing something obvious.

Specifically, in my vert program I am storing the shadow coords in the output as calculated by GetShadowCoord when passing in the result of GetVertexPositionInputs. In the frag program, I am using those shadow coords as an argument to GetMainLight to retrieve the Light struct. I am using the shadowAttenuation from the returned struct and, for now, simply multiplying it by the colour sampled from the main texture.

The result currently looks like this. On the left, there is an object above casting a shadow. On the right, the object is in full light.



Does anyone have any thoughts? Do I need to handle the shadow depth manually and, if so, is there any documentation on how to access those values?

 

Update:

I woke up after a good night's sleep and realized that depth is being handled during casting, not sampling. I updated my shader to to use the built in ShadowCaster shader for the pass and the artifacts are gone

specifically I used

UsePass "Universal Render Pipeline/Lit/ShadowCaster