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Industry breakdown · 2 min · 10/9/2026

Thrive: GPU Instancing for a City Builder

How Zugalu Entertainment fixed a CPU-bound vegetation system in Thrive: Heavy Lies the Crown with Unity GPU instancing, compute shaders and the Burst Compiler.

What happened

Zugalu Entertainment's medieval city builder, Thrive: Heavy Lies the Crown, was held back by a CPU-heavy vegetation system. They replaced it with GPU instancing: compute shaders feed a single buffer, with the Burst Compiler speeding up the CPU side, which freed frame time for a busy, living city.

Why it worked

  • The bottleneck was found and named before any rewrite.
  • Moving many similar objects to GPU instancing removed per-object CPU cost.
  • The fix was an architecture change, so it keeps paying off as the city grows.

What we'd take into a client project

  • In Unity, profile CPU and GPU separately; many 'graphics' problems are CPU submission problems.
  • For large counts of similar objects (vegetation, crowds, debris), plan instancing from the start.
  • Use Burst and the job system for hot CPU loops before reaching for bigger rewrites.

Related

Note: Feative Studios was not involved in this project. This breakdown summarises what the developers have shared publicly; the takeaways are our own.