I’ve been building on Roblox since around 2013-14, and in that time I’ve always heard that whenever two or more parts are trying to occupy the same space (intersecting), it causes lag. I’ve always put a lot of time into my builds to try to reduce intersecting parts as much as possible to keep them from lagging, but after seeing some large-scale builds and front-page games that are full of intersecting parts I’m wondering if it is even necessary.
To get on with the question, in your experience do intersecting parts cause lag?
Yea you can intersect parts when both are anchored and things will be fine.
But when one or more isn’t anchored, then physics will apply and one or both parts might spaz out and fling across the map, or maybe it just moves slightly away from eachother, but it used to do that, kinda like an explosion effect. I mean try spawning 50 parts in the same vector3 and see what happens
Brickbattle and Mining games are the most easily affected by overlapping issues.
When two parts are anchored the intersection is not an issue. The issue arises when the parts are unanchored and you need them to rely on each other for structure. I am very aware of this because I am working on a brickbattle game. If two parts are overlapping it can seriously mess up the physics. Characters will have a weird drift when they step on a part or may not even be able to stand on the part as it has appearance but no collision. One way to avoid possible collisions is to make sure you author the part in the center and the the coordinates have as few decimals as possible. This is a concern of you are cloning elements that are later copied into the game.
Again, theses are only concerns of you need the parts to not be anchored or collision is off. If you are working with anchored parts then disregard my warnings. It will become obvious in early testing what your requirements will be.
As the others have said if they are unanchored they will cause lag but if they both are anchored I am not sure. If the anchored parts were to cause any lag it probably would be a very small amount. I would try to avoid parts in parts in a game as in my opinion it just looks really messy as you can slightly see the other part glitching through.
The only major issue that I have encountered is the issue with Z-Fighting. That can be easily fixed by changing the value by .01 on the Y-Axis. As for the issue with performance I have not experienced anything detrimental to perfomance from having intersecting parts or meshes as long as they are anchored. Likewise, having unanchored parts intersecting has been something that has hurt overall performance from my experience.
