Depth-volume decals

Depth-volume decals rebuild the receiving surface from the camera depth texture, so the rendering camera has to produce one, and the decal volume has to intersect opaque geometry.

Under the Universal Render Pipeline they also need the CrowPSX Depth Volume renderer feature on the active Universal Renderer; without it URP hands the decal last frame's depth or a vertex-snapped surface and the decal drifts or flickers as the camera moves. Select the decal material and use the inspector's Add To Renderer action, or add it manually with Add Renderer Feature > CrowPSX Depth Volume.

Most surfaces require no stencil setup. To prevent decals on a particular material:

1. Set the surface material's Optional Stencil / Decal Masking preset to Block Decals.
2. Set the depth-volume decal material to Respect Blockers.
3. Use Receiver and Test Receivers only when an explicit allow-list is required.

Blocker and receiver flags use separate stencil bits and can coexist on the same material.

CrowPSX/Decals/Depth Volume#

A box-volume projected decal for stains, grime, graffiti, fake shadows, puddles, and overlays. It includes multiple decal blend modes, mask/channel selection, noise breakup, opacity, independent unlit and HDR-emission output, alpha shaping and clipping, dithering, edge fade, depth/thickness fade, distance fade, depth bias, culling, and stencil controls. The decal volume must intersect the receiving geometry.

The decal rebuilds its receiver from the camera depth texture, so the rendering camera has to produce one, and it never writes depth itself. Under the Universal Render Pipeline it additionally requires the CrowPSX Depth Volume renderer feature on the active Universal Renderer, which forces a snap-free depth prepass before the transparent queue. The material inspector detects a missing feature and offers an Add To Renderer action.

Unlit Strength controls the ordinary projected decal color. HDR Emission Color and HDR Emission Strength add a separate unclamped contribution that can drive bloom with an HDR camera; setting Unlit Strength to 0 creates an emission-only decal. As a screen-projected transparent effect, a depth-volume decal does not act as a realtime light or contribute to baked global illumination.

Use Normal (Alpha) for graffiti, painted markings, stickers, and ordinary colored decals. It uses standard source-over blending and is fully opaque wherever the resulting alpha is 1; Alpha Clip can provide hard cutout edges. Multiply is intended for dirt, soot, shadows, and stains, while the additive modes are intended for light and glow.

Depth-volume decals use Respect Blockers by default: ordinary surfaces need no stencil setup, while any surface using Block Decals prevents the decal from appearing on its visible pixels. Receiver plus Test Receivers provides an optional allow-list workflow. Receiver and blocker flags occupy separate stencil bits and can coexist.