Dynamic shadows artifacts

[Deathrey (DeathreyCG)]

@Kalle-H

With proper slope scaled depth bias filtering could be cheaper than it’s now. Filtering also could be optimized by using hardware bilinear comparision sampler where it is possible. Currently every sample is separately doing soft comparision.
Related code.

// The standard comparison is SceneDepth < ShadowmapDepth
// Using a soft transition based on depth difference
// Offsets shadows a bit but reduces self shadowing artifacts considerably
float TransitionScale = Settings.TransitionScale; //SoftTransitionScale.z;
float ShadowFactor = saturate((ShadowmapDepth - Settings.SceneDepth) * TransitionScale + 1);

I’d tend to agree here. It is just that the actual performance gain is hardly measurable. This is mostly due to the fact that large part of 4 in 1 comparison gain is the actual 4 in 1 texture fetch, which is already used. It boils down to 1 MAD and 1 SUB instructions less minus cost of hardware comparison per 4 samples, which is… well… not much these days, but still something.

But following the same logic, I’d say that ditching whole TransitionScale, and letting user tweak the depth bias per-cascade(not a replacement for slope-scaled bias, just alternative approach to the goals, that are set for existing system) would be good alternative, don’t you think?