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pmndrs / postprocessing

A post processing library for three.js.
zlib License
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Incorrect use of depth texture attachments #225

Open vanruesc opened 3 years ago

vanruesc commented 3 years ago

Description of the bug

The current depth texture system assumes that a depth texture can be assigned to a render target at any time. This assumption is incorrect as render targets are initialized once when they are used. Certain pass chains will cause the internal frame buffer to be initialized with a basic depth buffer attachment and the subsequent assignment of a depth texture won't have any effect. As a result, the depth texture won't contain the depth information of the rendered scene.

To Reproduce

  1. Add a ClearPass to the composer.
  2. Add a RenderPass to the composer.
  3. Add an EffectPass containing a depth-based effect such as SSAOEffect to the composer.
  4. See the effect fail due to missing depth information.

Expected behavior

Depth-based effects shouldn't fail with certain pass chains. One potential solution would be to assign the depth texture to a dedicated render target for geometry passes. Going one step further, a more complex render target management system could be implemented to allow passes to explicitly define input and output buffers.

Library versions used

vanruesc commented 3 years ago

Added a temporary fix in postprocessing@6.17.2.

alexpineda commented 3 years ago

I'm having this issue with 6.19.3. I'm not sure if it's something I'm doing something wrong on my end but seeing this ticket it seems to confirm my suspicion of missing depth information, even though the needsDepthTexture and the following logic execute correctly. My example follows closely to yours, RenderPass with clearPass enabled -> EffectPass with DepthEffect. Also important to note that I'm able to use DoF and SMAA, both of which use depth, without issue. Edit: Never mind this. It's just that my camera is really far away. I had assumed the depth information would be relative. Cheers.

vanruesc commented 5 months ago

Depth texture management is fixed in the postprocessing v7 alpha which will eventually replace v6.

I'm keeping this ticket open until v7 lands in case someone stumbles over this bug.