Daniel Chia 0a881ab37f Cascaded shadow maps: Fix prepass ortho depth clamping (#8877) ... # Objective - Fixes #8645 ## Solution Cascaded shadow maps use a technique commonly called shadow pancaking to enhance shadow map resolution by restricting the orthographic projection used in creating the shadow maps to the frustum slice for the cascade. The implication of this restriction is that shadow casters can be closer than the near plane of the projection volume. Prior to this PR, we address clamp the depth of the prepass vertex output to ensure that these shadow casters do not get clipped, resulting in shadow loss. However, a flaw / bug of the prior approach is that the depth that gets written to the shadow map isn't quite correct - the depth was previously derived by interpolated the clamped clip position, resulting in depths that are further than they should be. This creates artifacts that are particularly noticeable when a very 'long' object intersects the near plane close to perpendicularly. The fix in this PR is to propagate the unclamped depth to the prepass fragment shader and use that depth value directly. A complementary solution would be to use [DEPTH_CLIP_CONTROL](https://docs.rs/wgpu/latest/wgpu/struct.Features.html#associatedconstant.DEPTH_CLIP_CONTROL) to request `unclipped_depth`. However due to the relatively low support of the feature on Vulkan (I believe it's ~38%), I went with this solution for now to get the broadest fix out first. --- ## Changelog - Fixed: Shadows from directional lights were sometimes incorrectly omitted when the shadow caster was partially out of view. --------- Co-authored-by: Carter Anderson <mcanders1@gmail.com>		2023-06-21 22:00:19 +00:00
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src	Cascaded shadow maps: Fix prepass ortho depth clamping (#8877)	2023-06-21 22:00:19 +00:00
Cargo.toml	update bitflags to 2.3 (#8728)	2023-06-01 08:41:42 +00:00