Hello, after months and endless attempts at trying to figure out the Memory Thermometer and what effects it in UEFN, I’ve come to the conclusion that it is completely and utterly broken. Here’s why.
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Failure 1. The memory thermometer’s job is to estimate your islands impact on performance. It does no such thing. You can create a 100k Memory island and have it vastly out-perform a 10k memory island. Or just make a simple verse script to bog down the server. Or spawn 100k Niagara particles. Or animate 100 props in Verse. All of these things, and many more are cheap on memory cost but destroy performance.
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Failure 2. You can increase memory by as much as 15-20% simply by turning off “Is Spatially Loaded” in the World Partition settings of a Fortnite Asset that has it’s transformed adjusted by a Sequence. (Yes, really).
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Failure 3. No 2 users of a project ever have the same memory, often varying by as much as 20% between users.
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Failure 4. Nanite destroys props and increases memory significantly over traditional LODs. This is a 2 part process.
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- Create and import a large (physical size) prop that has moderate detail (eg. 50k verts).
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- Notice that it’s detail is destroyed by Nanite on default settings.
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- Attempt to fix the asset by increasing fallback triangles to 100% (the only method that works to preserve detail).
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- Watch as memory explodes in value by as much as 50% of budget.
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Failure 5. There’s no real way to cross reference how changes in your project affect memory. Even after memory calculation, the numbers never make any sense and are seemingly arbitrary. Even with Fortnite assets.
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Failure 6. The cost of Devices is still wildly inconsistent. A Single
Dirt Spawneris 10k. You can place 500Sedan Spawnersfor the same cost.
