UnityURP-Procedural-DrawMeshInstancedIndirect

October 4, 2025 · View on GitHub

Procedural grass & vegetation rendering in Unity URP using DrawMeshInstancedIndirect with FilterMap artist-editable mask control.

Unlike many "Mobile DrawMeshInstancedIndirect" examples, this project is truly mobile-friendly:
it avoids SSBO (StructuredBuffer) and uses RenderTexture to store results, making it compatible with a wide range of Android devices.

Performance Example

You can directly test the demo on Android devices using the APK below:
Download UnityURP-Procedural-DrawMeshInstancedIndirect.apk (Google Drive)

Live Preview (Supports Forward+)

Procedural Grass Demo

Demo Video

Demo Video

✨ Features

  • Procedural instance generation — no pre-generated assets or transform buffers
  • FilterMap editing support — paint distribution masks directly in the editor
  • WeightMap multi-color control — different colors = different vegetation types
  • DrawMeshInstancedIndirect pipeline — maximum GPU efficiency for large-scale rendering
  • Verified on mid-range Android devices (Galaxy S10 shown above)

📱 Why Mobile-Friendly?

Many existing "Mobile DrawMeshInstancedIndirect" examples rely on StructuredBuffers (SSBO)
to store instance data. This works on PC and some high-end devices, but fails on many Android phones
(e.g., Samsung Galaxy S10).

This project is designed for broad mobile compatibility:

  • Stores results in RenderTexture (not SSBO)
  • Runs smoothly on mid-range Android hardware
  • Avoids PC-only assumptions — every feature has been validated on real devices

If your goal is to support the majority of mobile devices,
this design choice makes a critical difference.

🎨 Why FilterMap?

Traditional approaches often require either:

  • Pre-generated transform arrays (huge memory cost)
  • Manual placement (time-consuming for artists)

With FilterMap, distribution becomes procedural + editable:

  • Artists paint masks (brush tools, multiple colors)
  • The GPU generates variation & randomness
  • No manual placement required, instant feedback in-editor

This workflow bridges procedural generation with artistic direction.

📖 Learn More

Read the full technical article on Google Blog

🔍 Looking for a Complete Solution?

If you need a ready-to-use, production-level system with:

  • Powerful Compute Shader brush tools for painting vegetation
  • Automatic Ground(Any Mesh) height & normal alignment
  • Support for four vegetation types (billboard-based)
  • Built-in wind animation and large-scale character interaction
  • User-friendly Unity Editor integration

Check out GPUPlantPainter on the Unity Asset Store.

For advanced workflows with procedural random curve vegetation effects (Ghost of Tsushima style),
see: GPUGrassBladePainter on the Unity Asset Store.