Procedural Volumetric Clouds - URP

Volumetric Clouds is a ray-marching cloud renderer for the Universal Render Pipeline. It draws a true 3D cloud layer wrapped around a planetary sphere — clouds you fly through, that curve down to the horizon, that self-shadow, catch the sun on their rims, and fade into the haze with distance. Every noise texture is generated on the GPU at runtime from a single seed. There are no cloud textures in this package, no baked flowmaps, nothing to import and nothing to keep in memory that you didn't ask for. Change the seed, get a different sky.

Skies you can actually art-direct

A procedural weather map drives coverage, cloud type and cloud-top height independently across the sky, so you get real structure: broken decks with clear gaps, towering cumulus over flat valleys, solid overcast. Cloud type morphs continuously from stratus through stratocumulus to cumulus. Wind scrolls the base shape, the fine detail and the weather pattern at different rates, so the deck evolves instead of sliding past as one rigid sheet.

Seven one-click presets — Midday Deck, Golden Hour, Aerial Broken, Twilight, Dreamy, Heavenly Blue and Misty Spires — each set the cloud parameters and drive your directional light's angle,

colour and intensity, so every preset lands as a complete, coherent lighting setup rather than a

pile of sliders.

Lighting that holds up

Dual-lobe Henyey-Greenstein phase function with a dedicated silver-lining term for backlit rims. A three-octave multiple-scattering approximation so thick clouds glow from within instead of going flat grey. A powder term for the dark edges on lit wisps, depth-probability shading for cauliflower crevices, and a sky-visibility pass that softly occludes valleys and undersides. Aerial perspective blends distant clouds into your haze colour.

Local cloud volumes

Drop a local cloud volume on any BoxCollider to get a fog bank in a valley, a cloud sea below a cliff, or mist rolling through a canyon. Up to four at once, marched in the same pass as the main layer so they light and composite identically. Want *only* local clouds? Set global coverage to 0, and the sky layer costs nothing.

Built to ship

Half-resolution raymarching with a depth-aware upsample that keeps geometry edges crisp. Temporal reprojection with neighbourhood clamping. Adaptive step sizes that spend samples where they matter and skip empty sky at double speed. A cheap-probe / refine split so expensive detail fetches only happen inside actual clouds. Every quality knob is exposed, and a `Lightweight` prefab is included as a tuned low-cost starting point.

Works in the Scene view and animates in Edit mode, so you author your sky without pressing Play.

Included

- 5 demo scenes covering aerial, ground-level, dreamy, heavenly, and lightweight setups

- 7 configured prefabs, ready to drag in

- A bonus gradient skybox shader with an adjustable moon disc and glow

- Full C# source and HLSL source — no DLLs, nothing hidden

- PDF installation guide

Key Features

- Fully procedural GPU-generated noise from one seed, zero imported cloud textures

- Raymarched 3D clouds on a planetary shell: fly through them, see them curve to the horizon

- Weather-map driven coverage, cloud type and per-location cloud-top height

- Continuous stratus → stratocumulus → cumulus morphing

- Multi-rate animated wind (base shape, detail, weather pattern)

- Dual-lobe phase + silver lining + 3-octave multiple scattering + powder + sky occlusion

- Aerial perspective and horizon haze that never visibly cuts off

- Up to 4 local box-constrained cloud volumes, lit and composited with the main layer

- 7 one-click presets that also drive your sun's angle, colour and intensity

- Half-res raymarch (1-4x) with depth-aware upsample — no bleeding over geometry

- Temporal reprojection with 3x3 neighbourhood clamping

- Adaptive stepping, empty-space skipping, cheap-probe/refine split, early-out

- Live in the Scene view and animated in Edit mode

- Per-camera history — Game view and Scene view stay independent

- Complete C# and HLSL source, no DLLs