Shadows are basically another camera rendering your scene. Sure, it's just a depth map, but all the geometry has to be taken into account - and potentially the transparency? If the sun is sharp, I suspect they're using Cascading Shadow Mapping. But point lights are a little different and they probably have a default camera resolution. Increasing the resolution of those cameras is how you go from "fuzzy" to crisp, but doubling the resolution only halves the size of your fuzzy pixels so it still doesn't look right... just a little better. So you go from a 1k to a 2k to a 4k to an 8k image of your scene, to get those delicious crisp edges!

And then your computer turns into a potato :P.

There are a bunch of approaches for improving on this in the Book of Shadows... NO NOT THAT ONE.

THAT ONE.

Or if you like pretty pictures, maybe these will help :)

https://threejs.org/examples/webgpu_shadowmap_opacity.html (Oh, colored, that's a FUN one)

Things like progressive might be nice if the scene changes "slowly" But they'll stink for avatars. VSM is nice, but expensive. CSM, works great for sunlight and contact shadow maps might be useful to fake some AO. Baked lights, on the other hand are AMAZING if you have a static light source, like a lamp, that you turn on and off - you can actually start to get into global illumination. And the opacity one? Can you imagine some yummy SL stained glass windows?!

Actually, I suspect if we need additional lighting, I'm surprised we don't have a a directional and spotlight, like in three. I realize we can emulate some of that with the advanced lighting model, but that CAN'T be an optimal solution for something like this. There's also gobo shadows, which are deliciously yummy. Those might give you the crisp shadows you crave, but they definitely require a lot of creativity to get them to work as you want.

Oh. Sorry. I ranted X_X. But maybe you could be a bit more specific and it will help the devs out :3.