Real Snow — Screen-Space Snow, Blizzard, Snow Cover, Frost on the Lens

Real Snow turns any scene into a winter scene without touching a single material or placing a single mesh. One fullscreen pass reads the depth buffer and the rig's top-down ceiling map and draws the whole thing: snow falling in a 3D flake field around the camera, a blizzard with spindrift and whiteout, a snow cover that builds over time on every surface the sky can see, frost creeping over the lens as the camera gets cold. Everything is driven by the Volume framework, so a snow volume over a mountain pass and a clear volume inside the lodge blend by themselves as the player walks between them. Snowfall. A world-anchored 3D field of flakes around the camera, seen through up to six soft shells — dust, flakes and clumps falling at their own speeds, every column at its own pace, swaying, tumbling, swirling in eddies, leaning with the wind, driven by gusts — plus big soft flakes crossing right in front of the lens that refract what is behind them. Real snowflake particles spawn around the camera wherever the sky is open and land on real geometry. Blizzard. Driven snow streaking across the view, spindrift streaming along the ground, sheets of snow thrown by gusts, whiteout haze with a visibility distance. From a light flurry to a whiteout with one slider. Snow cover. A cover that builds from bare to deep over a time you set, on everything the top-down ceiling map can see: not under roofs, awnings, arcades or bridges. Drifts gather in corners and on the lee side of walls, the windward side stays thin, steep slopes hold less, ledges and rails get their line of white, rime frosts the wind-facing walls, and heat sources melt discs around them. The cover is shaded from the frame under it, so it follows your lighting; it sparkles when the light hits it. Surface tags. Tag renderers with Real Snow Surface (or let the scene scanner classify them by material and texture names): bare surfaces (water, glass, ice) hold nothing, warm ones (lamps, engines, chimneys) melt their snow and the flakes above them, deep ones bank up, metal keeps a thin patchy layer, cloth only a dusting. The tags reach the shader through a lightweight per-pixel mask. Camera. Flakes land on the lens and melt into drops; frost grows in from the edges in combs of crystal spines with side branches, freezes over into rough ice behind them, refracts and glints — faster the longer the camera stays in the cold — and thaws when it leaves; fogging, a cold vignette, colour split at the frost edge. A wipe control clears the glass. Presets. Light Snow, Snowfall, Heavy Snow, Blizzard, Whiteout, Frozen (cover without snowfall), Night Snow, and a Stylized pair for cartoon-style games. All blendable from script. Setup. One-click Setup wizard for URP, HDRP and Built-in: it generates the pipeline wrappers, installs the renderer feature or the custom post process, creates the Volume profile and the scene volume. A Winter Street sample (awning, bridge, lamps, a fire barrel and a campfire as heat sources) and a Sandbox scene ship with baked lighting. Requirements and notes Unity 6000.3.21f1 or newer; URP 17.3 / HDRP 17.3 for the SRP paths (Render Graph only) HDR rendering with bloom and a tonemapper is recommended (the samples enable them); TAA or DLSS smooths the sheets Cost, measured in a URP player on an RTX 4090 at 1920×1080: Frozen 0.16 ms, Light Snow 0.27 ms, Snowfall 0.33 ms, Blizzard 0.44 ms, Whiteout 0.46 ms (about half at 1280×720). One full-screen pass that scales with pixel count; expect several times these numbers on mid-range GPUs, and use a lower resolution scale or fewer sheets there Screen-space by design: the cover exists where the depth buffer has surfaces and has no geometric thickness; the surface mask adds one extra pass over the opaque geometry (toggle per Volume) Demo footage The video and screenshots are Unity renders of the package's own Winter Street and Sandbox samples and of the publicly available Sponza atrium scene by Crytek, used only as a backdrop to show the