Post Effect Stack (formerly Post Effect Resource) is not an effect collection -- it's a small framework for combining Godot 4.7's CompositorEffect post-processing effects into an ordered stack, using only Resources and the Inspector.

What it does

• The stack is an ordered array of individual effect resources. Reorder, add, or remove them in the Inspector -- no code required, no manual intermediate buffer wiring.
• The stack runner executes the effects in order via CompositorEffect, on the Forward+ renderer.
• The same effect definitions can also be routed through a CanvasLayer path for Mobile and Compatibility rendering, where the compute path isn't available.
• Multi-pass effects (see Bloom) are supported alongside single-pass effects in the same stack.

What's included 10 working example effects: Grayscale, Vignette, ColorGrading (LUT), ChromaticAberration, Scanline, Grain, Pixelate, Bloom, Dither, Outline. These are demonstrations, not the product -- the stacking mechanism is.

Known limitations (no exaggeration)

• Compute (CompositorEffect) and CanvasLayer path switching is manual; there's no automatic renderer detection.
• Outline requires a depth buffer and has no CanvasLayer fallback.
• Bloom's CanvasLayer version is a single-pass approximation, not an exact match for the compute version.
• The compute path targets Forward+. On Mobile the color buffer isn't a storage image, so compute writes don't apply; on Compatibility CompositorEffect isn't available at all. Use the CanvasLayer path on both.
• With MSAA enabled on Forward+, only the POST_TRANSPARENT callback stage applies (this is the default). Outline's depth-based edges also thin out as MSAA increases.

Why Combining more than one post-processing shader in Godot usually means hand-building BackBufferCopy + Viewport chains per effect. This addon replaces that with an ordered array of .tres resources.

CompositorEffect is documented as experimental, but its public API hasn't had a breaking change since its introduction in 4.3 (August 2023), as of August 2026.

Renamed from Post Effect Resource in v0.2.0 to better reflect what the addon does -- see the README for migration notes if upgrading.

Built with AI assistance (Claude). Verified on Godot 4.7 / 4.7.1. MIT licensed.