Does using Intersections degrade game performance?

[Marko97_IT (Marko97)]

As per the title I was wondering if the use of intersections could degrade the performance of a game. I recently learned how to make some 3D models on Roblox because I don’t know how to use Blender yet, I also know that unions (UnionOperations) should be avoided because they severely degrade performance due to the fact that they create useless triangles. I should create a simple tunnel, instead of using union I tried intersection. Also consider that both parts are anchored. So could this create problems?

[VGVC2]

There isn’t really any special difference between intersections and unions (besides how they are created and the fact they’re separate instances) as far as I’m aware, you still have to pay attention to triangle count and collision fidelity like you would with unions.

[Marko97_IT (Marko97)]

I get the same result with both unions and intersections. As for counting triangles, I don’t know if there is a plugin that tells you this on Roblox. However, for the fidelity of the collisions (which I left on default), it is also available on the Meshes. I just wanted to understand how impactful an intersection was compared to a union (and at this point also with a mesh).

EDIT: I used a plugin called ‘PolyCounter’ and seems that my intersection has 12 polygons in total so it’s very good.

[VGVC2]

@Marko97_IT

EDIT: I used a plugin called ‘PolyCounter’ and seems that my intersection has 12 polygons in total so it’s very good.

there’s a bit on the properties window that tells you the triangles of a selected union/intersection…

[Marko97_IT (Marko97)]

Using Intersection rather than UnionOperation is apparently much better in terms of performance. While with the union I get 204 triangles, with the intersection I get 12.

[Scottifly]

Does that still work?
I remember using it when making Unions years ago and it worked well after making (or negating) a Union, but if I selected something else then went back to the Union it’d just show 0.

[VGVC2]

I find, sometimes, if you change the SmoothingAngle to an arbitrary number and back, it fixes the triangle count, but that’s only sometimes.

When that doesn’t work, I just grab a part, make it negative, have it not touch the union, then union that with the union I want to know the triangle count of since that technically updates it.
~

@Marko97_IT

Using Intersection rather than UnionOperation is apparently much better in terms of performance. While with the union I get 204 triangles, with the intersection I get 12.

What matters a lot in solid modelling is to pay attention to how you create the objects, there’s some technique involved in getting triangle counts low in unions, and for me, it involves using a lot of negative parts.