Accepted: OIT in Godot Engine
Context and Problem Statement
Render hair well.
Describe the feature / enhancement and how it helps to overcome the problem or limitation
Use “Shortcut” or “PPLL” to render OIT transparency.
Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams
Shortcut takes 4 passes but is faster.
TressFX technology uses order independent transparency.
(OIT). There are two variants. One uses a per-pixel linked list (PPLL), and the other uses a multi-pass method referred to as Shortcut.
The main decision to make is whether to use per-pixel linked lists or Shortcut. The Shortcut method can be generally faster, with an easier memory bound, but at the expense of some quality. The TressFX 4.1/Unreal 4.22 Engine integration uses Shortcut (although the shader for PPLL may still be present in the branch, it was/is unmodified/untested/unused). TressFX 4.1/Cauldron uses both Shortcut and PPLL.
If this enhancement will not be used often, can it be worked around with a few lines of script?
Avatars are a strength of V-Sekai.
Positive Consequences
No response
Negative Consequences
Code complexity.
Is there a reason why this should be core and done by us?
Reduz isn’t interested in OIT.
References
- https://raw.githubusercontent.com/GPUOpen-Effects/TressFX/master/doc/TressFX4xDeveloperGuide.pdf
- https://github.com/GPUOpen-Effects/TressFX/blob/master/src/Shaders/TressFXPPLL.hlsl
- https://github.com/GPUOpen-Effects/TressFX/blob/master/src/Shaders/TressFXShortCut.hlsl
- https://blog.icare3d.org/2010/07/opengl-40-abuffer-v20-linked-lists-of.html
- https://github.com/SaschaWillems/Vulkan/blob/master/examples/oit/oit.cpp
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