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Question How do I optimize terrains?

Discussion in 'World Building' started by faulknordonald, Oct 20, 2023.

  1. faulknordonald


    Sep 9, 2019
    I have 25 terrains in my scene and it appears to be slowing down Unity. How can I optimize this?

    I have 9 terrains for the open world area and 16 for the ocean.

    Also, each ocean terrain has 598 cube game objects for the ocean floor.
  2. Kurt-Dekker


    Mar 16, 2013
    All optimization journeys should at least start with the profiler: Window -> Analysis -> Profiler.

    Here's the standard blurbs:

    DO NOT OPTIMIZE "JUST BECAUSE..." If you don't have a problem, DO NOT OPTIMIZE!

    If you DO have a problem, there is only ONE way to find out. Always start by using the profiler:

    Window -> Analysis -> Profiler

    Failure to use the profiler first means you're just guessing, making a mess of your code for no good reason.

    Not only that but performance on platform A will likely be completely different than platform B. Test on the platform(s) that you care about, and test to the extent that it is worth your effort, and no more.

    Remember that you are gathering information at this stage. You cannot FIX until you FIND.

    Remember that optimized code is ALWAYS harder to work with and more brittle, making subsequent feature development difficult or impossible, or incurring massive technical debt on future development.

    Don't forget about the Frame Debugger either, available right near the Profiler in the menu system.

    Notes on optimizing UnityEngine.UI setups:

    At a minimum you want to clearly understand what performance issues you are having:

    - running too slowly?
    - loading too slowly?
    - using too much runtime memory?
    - final bundle too large?
    - too much network traffic?
    - something else?

    If you are unable to engage the profiler, then your next solution is gross guessing changes, such as "reimport all textures as 32x32 tiny textures" or "replace some complex 3D objects with cubes/capsules" to try and figure out what is bogging you down.

    Each experiment you do may give you intel about what is causing the performance issue that you identified. More importantly let you eliminate candidates for optimization. For instance if you swap out your biggest textures with 32x32 stamps and you STILL have a problem, you may be able to eliminate textures as an issue and move onto something else.

    This sort of speculative optimization assumes you're properly using source control so it takes one click to revert to the way your project was before if there is no improvement, while carefully making notes about what you have tried and more importantly what results it has had.

    "Software does not run in a magic fairy aether powered by the fevered dreams of CS PhDs." - Mike Acton
  3. faulknordonald


    Sep 9, 2019
    It's late for me so I'll read this tomorrow. Would just like to say, I did run the profiler, I'm still learning how to read it. I seen a few spikes but like 98% of it came from the editor.