What is more important? Part count or file size?

Hi,

So I am working on a big project that involves the construction of a big city. We have always been of the impression that a smaller part count would be better. Though I have recently come to the conclusion that the file size of a unioned building it is far more than the file size of a building with only parts. Meshed buildings is somewhere in the middle, with a decently less file size.

So what option would be better?

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Parts are much easier to compute and optimize than complex unions. Same goes for meshes. Parts are predefined shapes and Roblox has more control over them, which is not the case for your arbitrary shapes.

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So? What I can summarize from your response I suppose I need to avoid unioning the buildings?

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I’m not sure what kostis is talking about, but you should absolutely merge geometry together, at the very least by Union’ing them. If possible, you could even export these unions and optimize them further in an external modelling tool (such as Blender), as Roblox’s built-in mesh optimizer isn’t always perfect. Re-importing these as MeshParts shouldn’t be that much worse for performance than keeping them as Unions (in fact, I think they might be cheaper in terms of memory usage because Unions need to store extra information so that you can Separate them).

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Use Meshes, if you can’t than be with Parts. Not select Uinons cuz they are not optimized enough yet.

How come the file size on a building with only parts is far less than a building with only unions? For example, I have a building of 1MB, 200KB of which was one single union. I can see the same trend on other buildings.

What is the CollisionFidelity of your Unions? If it is set to PreciseConvexDecomposition, your place file can get bloated with additional cached collision information.

I hope you are not saying that you are just replacing cube Parts with cube Unions

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CollisionFidelity is always set to default. Some of our builders used to union everything together that was the same material and color. Now only complex shapes that are needed in the building are unions, the rest are parts. It does seem to work great on reducing file size, I suppose that is the best option to go for?