Quick Start

You need two things: the renderer feature and a volume override. Both take less than a minute.

1. Add the renderer feature

1. Open Project Settings / Graphics and locate your Universal Render Pipeline asset. Check Project Settings / Quality too, both places can hold a URP asset.
2. Open the Renderer used by that asset.
3. Click Add Renderer Feature and pick Global Dirt Render Feature.

The feature has a Cameras Layer Mask, Everything by default. Only cameras on those layers run the effect, so a weapon, UI or minimap camera on its own layer stays clean and costs nothing.

2. Add the volume override

1. Add a Volume to your scene (GameObject / Volume / Global Volume), or use an existing global volume.
2. In its profile, click Add Override and pick Kronnect / Global Dirt.

3. Raise Intensity

Enable Intensity in the override and raise it. Intensity defaults to zero, and at zero the effect is completely off and costs nothing, so nothing happens until you ask for it.

4. Start from a preset

At the top of the override there are three presets: Dry (light settled dust with barely any staining), Grimy (dirt led, some dust, a little moss) and Abandoned (heavy dirt with moss taking over the sheltered spots). In Deferred and Deferred+, Grimy also dulls the metal and Abandoned ages and rusts it. Forward cannot tell metal apart, so there the presets leave Metal Aging and Rust off. Each one sets Intensity to 1 and writes a complete look in one click, and you can move every slider afterwards. None of them touches metal aging or rust, which stay where you left them. The Quick Settings button applies the Grimy setup, and Clear Effects turns every effect back off while keeping Intensity, Quality, Show In Scene View and the layer masks.

5. Or raise the effects by hand

Open Surface Deposits and raise the Strength of Dirt, Dust or Moss. Each one starts at zero. A good first try: Dirt at 0.5, Dust at 0.5, Moss at 0.3.

Metal Surfaces is a section of its own for a reason. Metal Aging and Rust are meant for metallic materials and work best on the Deferred and Deferred+ rendering paths, because that is where the metalness of your materials is available. On Forward there is no metalness to read, so both reach every surface, metal or not, as an approximation. Keep them at zero on Forward unless you want that look.

6. Compare

Enable Compare in the General Settings section to see the scene with and without the effect, split by a movable line. This is the fastest way to judge how far you want to push it.

7. Go further

To vary the aging across the scene, add a Zone from GameObject / Effects / Global Dirt Zone. To change it on one object, keep an object clean, or keep the dirt attached to something that moves, add a Global Dirt Object from Component / Effects / Global Dirt Object.

If nothing shows up, the inspector tells you why: it warns when the renderer feature is missing and offers a button that selects the active Universal Render Pipeline asset, whose Renderer holds the feature list. See Troubleshooting for the rest.