Ultimate Compositor Cavity for Blender

Ultimate Compositor Cavity is a compositor nodegroup that helps you add cavity (angular ridge and valley) effects to your renders.

A simple Blender scene

The scene composited using the Ultimate Compositor Cavity node

I really like Blender’s viewport cavity feature in solid/Workbench mode. It has screen-space (single-pixel) and world-space (ambient-occlusion-style) cavity passes, and I think it looks the best when both are turned on.

Unfortunately, Blender has no built-in way to get the cavity effect in EEVEE and Cycles renders. But you can use Ultimate Compositor Cavity to generate screen-space cavity passes in the compositor. The nodegroup’s 3 controls enable you to make various different styles of cavity.

Examples: Classic Cavity Styles

Ultimate Compositor Cavity excels at highlighting thin ridges and valleys.

Thin Cavity

“Contrast Pop” Cavity

Examples: AO-esque Cavity Styles

The node setup can be pushed further to produce ambient-occlusion-like effects.

Video-Game-SSAO-Style Cavity

Stylized Fake Global Illumination Effect

Examples: Depth-Emphasizing Cavity Styles

While the nodegroup wasn’t designed for this purpose, it can be used to accentuate depth between foreground, midground, and background objects.

Moderate

Extreme

Notes

• The nodegroup is computationally intensive and is not suitable for realtime compositing unless your GPU is NASA-tier. It runs way faster on GPU than on CPU, so make sure GPU compositing is enabled.
• The nodegroup can only calculate cavity on real geometry, so the effect doesn’t apply to ridges and crevices formed by normal maps and bump maps.
• Because the nodegroup does its computations based on the Z (depth) pass, the nodegroup can’t see through faces that have alpha transparency.
• The effect does not scale with the render resolution. The settings in the examples may not produce the same results in your scenes. The settings you need depend on world scale, image dimensions, and camera FOV.
• The maximum falloff is size-limited in screen space in pixels (max falloff is 64 pixels) because of Blender’s compositor’s limitations and computational resource restrictions (high-resolution blur is expensive).