Building a Cross-Platform GPU Procedural Grass System in Unity URP (Optimized for Mobile)

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Hello Devtalk Community,

I’m sharing a GPU-Driven Procedural Grass System for Unity URP, heavily optimized for mobile. Key Features & Challenge: This system handles Procedural Generation and implements precise ViewFrustum, Distance, and FilterMap Culling entirely on the GPU. However, I faced the common mobile hurdle: SSBOs being unstable in the Vertex Shader on low-end hardware. My Solution: To ensure robust cross-platform stability, I bypassed the unstable SSBO path. The Compute Shader now writes instance data (including culling results) to a RenderTexture (UAV), which is then sampled by the final shader. Seeking Expert Opinion: This RenderTexture method guarantees stability, but introduces potential texture cache overhead. Is this the most practical performance/stability trade-off for commercial URP Mobile development today?

I’m keen to hear your critical thoughts. — Full Technical Breakdown (Including implementation details on Culling):

Source Code (GitHub):

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Just to close the loop on this thread:

The discussion influenced how the system evolved,
especially regarding cross-platform stability and GPU-only workflows.
I later summarized the technical reasoning and lessons learned in this write-up:

The same approach has since been packaged into a Unity tool for practical use: