How do can I remove ledges/lips from outside corners without unions/meshes

I’ve searched for tips on this kinda thing but can’t find anything very useful that actually is giving me information on how people usually make these kind of builds work

If you want to align the corners together, use this.

If you want to fix the Z-fighting, use this.


The most efficient way would be to use a surface align plugin in this instance.

But that doesn’t work in all cases, when two parts are also tilted for example:

In cases like this you could also use it in conjunction with a gap fill plugin, but that would not only look bad,
it would also be less efficient. If you’re not going to use a third party software like Blender, I would suggest going with CSG.

I usually advise against using CSG operations (Unions), but that is only the case with more complex geometry, which this is not.

CSG would work in all of these cases if it is just to remove excess material in any outwards facing corners, and the method goes as follows:

  1. Copy both Parts that make up the corner.

  2. Move the copied Part(s) outwards using the Move tool, with the grid size being the Part’s thickness.
    (in the case above 1 stud)

  3. Resize both Parts to cover just about the excess material of your main Part, while leaving enough headroom. (I would adive to give it 1 stud of headroom on all 5 sides.)

  4. Negate both Parts.

  5. Union in a diagonal fashion, Union a main Part with the Negative Part stemming from the other.

When done right you have something like this (pre-Union):

And to clarify what I mean with “Union in a diagonal fashion”, in the example above I created the transparent green Part from the red one, and the red one from green. So when you Union, you can use the Part created from the other to take away any excess material. In this case you’d Union the corresponding colored Parts.

The end result (with color and texture) would look like this:

This example is a little more complex then what you were asking for, but this is just to show you that this method will work in any of these cases. With gap fill you’d be creating additional geometry which would obviously be less efficient performance wise. Basic operations like this will be solved correctly and will hold the same amount of vertices / triangles as a regular Part.

CSG_Example.rbxl (28.1 KB)

This file contains the above displayed Union, you can seperate them to see how this came to be in case any of the previously mentioned steps weren’t clear. You can always PM me on the forum if you have any additional questions about this method.