Additional Topics

Moving Objects (Characters, Vehicles)

Global Snow paints snow per pixel in the deferred pass. For every surface it looks at the world-space normal (only faces pointing up get snow) and at the zenithal coverage captured at that spot (nothing under a roof gets snow). It does not know whether an object is static or moving, which has three consequences for characters and vehicles:

• When the object tilts or animates, the snow re-settles on whatever faces up at that moment, so it slides across the mesh.
• The snow depends on where the object is now: driving under a bridge or into a garage removes it, and the zenithal capture is refreshed at intervals, so a fast vehicle can carry stale coverage for a moment.
• The snow textures are projected in world space, so the pattern drifts over a moving surface.

For slow props in open areas this is often acceptable and needs no setup. For vehicles and characters, use the steps below: exclude the object from the global effect, then give it its own snow material.

Step 1 - Exclude the Moving Object

Remove the global snow from the object so the scene-wide effect no longer paints it. Choose one of these two methods:

A) Layer Mask. Put the object on its own layer and remove that layer from Coverage > Layer Mask in the Global Snow inspector. Objects on the Default layer (layer 0) are never excluded by the mask, so the object must have a dedicated layer for this method to work.

B) GlobalSnowIgnoreCoverage component. Add it to the root of the vehicle or character. It applies to every renderer in its children and works on any layer.

The related settings live in Coverage > Exclusion of the Global Snow inspector: Default Exclusion Layer (an unused layer Global Snow borrows during the exclusion pass, default 27), Exclusion Depth Bias, Exclusion Double Sided and Default Cut Off.

Step 2 - Apply the Moving Object Snow Shader

Global Snow includes a material shader that renders the snow inside the object's own material, so the snow stays on the object wherever it goes: GlobalSnow/Moving Object Snow/Opaque (folder GlobalSnow/Runtime/Resources/GlobalSnow/MovingObjects/SimpleLitSnow). It is based on the URP Simple Lit shader and keeps its inputs: Base Map, Base Color, Smoothness and Specular, Normal Map, Emission, alpha clipping and shadow reception. The snow uses the textures, relief, glitter and brightness of the Global Snow component in the scene, so it matches the look of the terrain snow.

1. Complete Step 1 first. If the object is not excluded, the deferred pass paints a second layer of snow over the material.
2. Duplicate the object's material and switch its shader to GlobalSnow/Moving Object Snow/Opaque. Reassign the Base Map and Normal Map if they were not carried over.
3. Adjust the snow parameters of the material.

What this shader gives you and what it does not:

• The snow amount no longer depends on the zenithal coverage or on the object's position: the vehicle keeps its snow under bridges, inside buildings and while the coverage map is refreshing.
• The slope test still uses the world normal, so snow sits on the top surfaces of the object and moves with it when it tilts, as real snow would.
• Only an opaque variant is provided. Transparent parts (glass) keep their own material.
• Each material has its own Coverage, so a convoy can mix clean and snowed vehicles.

Step 3 - Vehicle Wheel Tracks (Optional)

Terrain marks are collision driven. Enable Features > Terrain Marks in the Global Snow inspector (see Terrain Marks parameters) and make sure the physics contact exists: the vehicle needs colliders and a Rigidbody, and the ground needs a collider. Global Snow adds its collision listener to every Unity Terrain automatically; for ground made of meshes, add the GlobalSnowCollisionDetector component to the ground object.

Add GlobalSnowColliderExtraInfo to the vehicle root (or to each wheel) to control the marks it leaves:

Character Footprints

The GlobalSnowFootsteps component makes a character leave a footprint under each foot, exactly where it lands, with independent left and right prints. In the Third Person footprint mode, Global Snow adds this component automatically to the assigned Character Root; you can also add it manually to any character or NPC.

Feet are auto-detected on humanoid rigs from the Animator. For other rigs (animals, robots), assign the feet transforms manually: even entries are left feet, odd entries are right feet.

Coverage Mask Editor

The Coverage Mask allows you to paint snow on or off using a texture. The alpha channel controls opacity: 1 = full snow, 0 = no snow.

Inspector Setup

Scene View Mask Editor

Enable the Mask Editor section in the inspector to paint directly in the Scene View:

• Resolution - 1024 for coarse, 2048-8192 for fine detail.
• Brush Mode - add or remove snow.
• Width / Fuzziness / Opacity - brush settings.
• Fill Mask - reset to fully snowed.
• Clear Mask - remove all snow from the covered area.

Per-Object Exclusion (GlobalSnowIgnoreCoverage)

Attach this script to any GameObject for fine-grained control over snow coverage. It affects the object and all its children.

Per-Collider Settings (GlobalSnowColliderExtraInfo)

Attach this script to any GameObject with a collider to customize how it interacts with terrain marks. Also supports WheelCollider automatically - wheel-ground contact points are reported for terrain marks each frame.

Transition / Lerping Between Profiles

All Global Snow properties are animatable. For quick transitions between two snow configurations, use the GlobalSnowLerp script:

1. Add the Global Snow Lerp component to any GameObject.
2. Configure Profile 1 and Profile 2 with different snow settings.
3. Adjust the Transition slider (0 = Profile 1, 1 = Profile 2) to blend between them.

Coverage Update Methods

The zenithal depth pass can be updated in several modes:

Next Steps

• Scripting Support (C#) - runtime API for mask painting, footprints, and snow queries.
• Troubleshooting - solutions to common issues.