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by frogblast 958 days ago
Despite the original post talking about DOTS rough edges, I didn't see anything in that article that actually suggested DOTS was the cause: that would cause CPU overhead, but it seems like they simply have a bunch of massively over-detailed geometry, and never implemented any LOD system.

Maybe they could have gotten away with this with UE5's Nanite, but that much excessive geometry would have brought everything else to its knees.
3 comments
baazaa 958 days ago
The author's point is that poor support for DOTS meant the devs had to roll their own culling implementation which they screwed up.
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iMerNibor 958 days ago
> Maybe they could have gotten away with this with UE5's Nanite

Exactly.

If unity actually delivered a workable graphics pipeline (for the DOTS/ECS stack, or at all keeping up with what UE seems to be doing) these things probably wouldn't be an issue.

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frogblast 958 days ago
DOTS/ECS has nothing to do with geometry LODs. Those are purely optimizing CPU systems.

Even if DOTS was perfect, the GPU would still be entirely geometry throughput bottlenecked.

Yes, UE5 has a large competitive advantage today for high-geometry content. But that wasn’t something Unity claimed could be automatically solved (so Unity is in the same position as every other engine in existence apart from UE5).

The developer should have been aware from the beginning of the need for geometry LOD: it is a city building game! The entire point is to position the camera far away from a massive number of objects!

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iMerNibor 958 days ago
To quote from the blog post:

> Unity has a package called Entities Graphics, but surprisingly Cities: Skylines 2 doesn’t seem to use that. The reason might be its relative immaturity and its limited set of supported rendering features

I'd hazard a guess their implementation of whatever bridge between ECS and rendering is not capable of LODs currently (for whatever reason). I doubt they simply forgot to slap on the standard Unity component for LODs during development, there's got to be a bigger roadblock here

Edit: The non-presence of lod'ed models in the build does not necessarily mean they don't exist. Unity builds will usually not include assets that aren't referenced, so they may well exists, just waiting to be used.

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johnnyanmac 958 days ago
main issue is that DOTS and the whole HDRP/URP stuff started at about the same time, but the goals were completely different. So it would have been nearly impossible to get them working together while DOTS was a moving target. Devs already have multiple breaking updates from the alpha versions of DOTS, an entire GPU pipeline sure wasn't going to rely on that.

>Unity has a package called Entities Graphics

Well that's news to me. Which means that package probably isn't much older than a year. Definitely way too late for game that far in production to use.

oh, so they rebranded the hybrid renderer. That makes a lot more sense: https://forum.unity.com/threads/hybrid-rendering-package-bec...

I'm fairly certain the hybrid renderer was not ready for production.

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lowbloodsugar 958 days ago
Oh sure. I did not mean to imply that. Sorry.
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