GrassLite - Mobile Grass System for Unity URP

[BT] PERSIA VFX — GrassLite

HIGH-PERFORMANCE MOBILE GRASS SYSTEM FOR UNITY URP

REQUIREMENTS

GrassLite requires the Universal Render Pipeline (URP).

The Built-in Render Pipeline and HDRP are not supported.

Minimum supported Unity version: Unity 2022.3 LTS.

REAL MOBILE PERFORMANCE

100,000 grass blades demonstrated at approximately 60 FPS in the recorded demo scene on physical mobile devices:

- iPhone SE (3rd generation, A15 Bionic)

- Samsung Galaxy A54

The footage was recorded directly from physical Android and iOS devices, not from the Unity Editor or a simulated result.

The 100,000-blade Showcase configuration contains approximately:

- 100,000 grass blades

- 200,000 triangles

- 400,000 vertices

Performance varies depending on the device, render resolution, camera view, lighting, blade settings, shader settings, and overall scene complexity.

WHAT IS GRASSLITE?

GrassLite is a mobile-first baked-mesh grass system for Unity URP.

Grass is generated in the Unity Editor and baked into a mesh. In the default workflow, the grass mesh does not need to be regenerated at runtime.

Paint exactly where grass grows, exclude trees and buildings, customize the visual style, and add real-time bending for players, NPCs, vehicles, and other moving objects.

WHY GRASSLITE?

Many grass systems are designed for desktop hardware first and optimized for mobile later.

GrassLite is designed around mobile constraints from the beginning, with an editor workflow focused on practical setup, visual control, and predictable performance.

Key benefits:

- Tested on physical Android and iOS devices

- Editor-generated baked-mesh workflow

- No compute shader required

- Unity Terrain component is not required

- Scene View mask painting

- Exclusion Zones

- Real-time grass interaction

- Natural and Stylized visual presets

- Mobile-focused performance presets

FEATURES

PERFORMANCE

- Grass is generated and baked in the Unity Editor

- No runtime grass-mesh generation in the default baked workflow

- Three recommended performance presets

- Additional 100,000-blade Showcase configuration

- Designed primarily for mobile URP projects

- Also suitable for desktop URP projects

- No compute shader required

RECOMMENDED PERFORMANCE PRESETS

Mobile Fast — approximately 8,000 blades

Recommended starting point for lower-end and older mobile devices.

Balanced — approximately 25,000 blades

Recommended starting point for mid-range mobile devices.

Beauty — approximately 50,000 blades

Designed for higher-end mobile devices and desktop projects.

SHOWCASE CONFIGURATION

Showcase — 100,000 blades

The Showcase configuration is used in the recorded real-device performance demonstration.

It is intended for testing and presentation and is not a universal recommendation for every project. Test and adjust the blade count according to the requirements of your target hardware and scene.

PLACEMENT

- Works with compatible mesh-based surfaces in URP

- Unity Terrain component is not required

- Source mesh must contain UV0 coordinates

- Source mesh must have Read/Write enabled

- Paint grass placement directly in Scene View

- Use an external grayscale texture as a placement mask

- Mesh UV and World XZ mask-mapping modes

- World XZ mode is useful for low-poly terrain with distorted or poorly distributed UVs

- UV0 is still required when using World XZ mode

- Force Up Direction corrects blade orientation on low-poly surfaces

EXCLUSION ZONES

Keep grass away from trees, rocks, buildings, paths, and other objects.

Supported exclusion shapes:

- Circle

- Box

- Mesh-based shape

Global padding controls can be used to expand the no-grass area around exclusion objects.

VISUALS

- Custom URP grass shader

- Mobile shadow support

- Root darkness and tip brightness controls

- Adjustable blade height and width

- Curvature and twist controls

- Multiple blade segments

- Cross-blade support

- Natural and Stylized blade presets

- Breeze, Storm, and Custom wind modes

- Optional point-light support

Point-light support requires Additional Lights to be set to Per Pixel in the URP Asset and may have a significant performance cost on mobile devices.

INTERACTION

- Real-time grass bending and flattening

- Supports up to 8 simultaneous interactors

- Suitable for players, NPCs, vehicles, and other moving objects

- Independent Strength, Push, and Flatten controls

- Interactor radius can be adjusted for different object sizes

WORKFLOW

- One-click Quick Setup from the Inspector

- Scene View mask painting

- Texture-based placement masks

- Rebuild grass directly from the editor tool

- Runtime rebuild option for temporary previews during Play Mode

- Save generated grass as a reusable Prefab

- Interactive Demo Scene with live runtime controls

- Full documentation and Quick Start Guide

MESH REQUIREMENTS

The source mesh must:

- Contain UV0 coordinates

- Have Read/Write enabled

- Use a compatible MeshFilter-based surface

Supported examples:

- Standard environment meshes with UV0

- Low-poly terrain meshes with UV0

- Modular ground meshes with UV0

- Custom environment meshes with UV0

Meshes without UV0 are not supported and must be unwrapped before use.

World XZ mode changes how the placement mask is mapped, but it does not remove the UV0 requirement.

CURRENT LIMITATIONS

LOD and frustum culling are temporarily disabled in v1.0.1 while the system is being redesigned and tested.

The related Inspector controls remain visible but are disabled and have no effect at runtime in this version.

Dedicated large-world and open-world LOD support is not currently available.

LOD support is planned for a future update. No release date has been announced.

For large environments, test the current baked-mesh workflow against the requirements of your target hardware before production use.

WHAT'S INCLUDED

- GrassLite core runtime system

- Full editor toolset

- Custom URP Grass Shader

- Terrain Diffuse Shader with mobile shadow support

- Interactive Demo Scene with runtime controls

- Sample terrain mesh — 40 × 40

- Default grass texture

- Default paint mask

- Scene View painting tools

- Exclusion Zone components

- Grass Interactor component

- Full documentation

- Quick Start Guide

SYSTEM REQUIREMENTS

- Unity 2022.3 LTS or newer

- Universal Render Pipeline required

- Built-in Render Pipeline is not supported

- HDRP is not supported

- Source mesh with UV0 coordinates required

- Source mesh Read/Write access required

[BT] PERSIA VFX

Built for developers targeting mobile hardware.