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Fixed in 2021.1.X



Found in




Issue ID




[Terrain] High CPU usage from Terrain.UpdateMaterials method when Editor is rendering terrain



How to reproduce:
1. Open attached project "" and scene Assets -> Scenes -> Bugs -> "TerrainBugReproScene"
2. Enter Play Mode
3. Observe CPU Usage in the Profiler window

Expected result: Rendering terrains should not take 1/3 to 1/2th of the frame's CPU budget
Actual result: Rendering terrains take 1/3 to 1/2th of the frame's CPU budget

Reproducible with: 2018.4.26f1, 2019.4.9f1, 2020.1.2f1, 2020.2.0a21

Note: This issue is also being discussed in this forum thread:

  1. Resolution Note (fix version 2021.1):

    Fixed in 2021.1.0a1

Comments (2)

  1. Tomcat9

    Jun 20, 2021 11:04

    Still no fix for 2020. So now I have the choice of using a 2020 version with this huge performance hit bug, or 2021 which is entirely a buggy mess itself. Terrible.

  2. i2eilly

    Dec 16, 2020 23:58

    Is there any chance this can be back ported to 2019.4 LTS, I am currently near the end of my project and this issue is still present in the LTS versions of Unity.

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