# Editing Nodes and Boolean Difference / Union

I wanted to try my hand at creating tessellations with LightBurn. Somehow, I haven’t quite gotten the knack of Boolean difference and union (or welding?) – perhaps by creating, selecting, and editing nodes. Suggestions?

The idea is, starting with a square, to cut (or create) a shape from one side and then attach it to the other side. The end result can be simply geometric translations and rotations – or like M. C. Escher’s work.

How do you want the end result to come out? I don’t think I am understanding what you are after here.

Edit: This might help you visualize the different effects available. Modifier Tools - LightBurn Software Documentation

• Union keeps the area covered by either shape - it merges them.
• Difference is the 2nd shape removed from the first.
• Intersection keeps the area covered by both shapes.

### Video Walkthrough of the Boolean Operations

Click for a Boolean demonstration video

The above video describes in more detail how the various Boolean operations differ, and why welding text to a circle should be done with a Boolean Union instead.

2 Likes

What I think I am having difficulty with is when two shapes SHARE a line. Does that in any way confuse the Boolean operators?

So in my pasted tessellation illustration, the left side of the square is shared with the left side of the shape which I want to CUT (from the left side of the square - Boolean difference) – and then the shape I want to append (to the right side of the square - Boolean union).

I also want to align the nodes of the square’s corners with the uppermost and lowermost nodes of the shape which I want to cut and append.

I appreciate your patience and assistance.

From this:

to this:

Is there a simple way to get this result?

Based on what I can see here, I would trim away what you don’t want using ‘Trim’ while in ‘Edit Nodes’. Post this file, so we can see what you are working with, we might be able to provide a few workflows to accomplish your goal.

1 Like

I will research trimming while in edit nodes.

When I select the shape(s) and then select “Edit Nodes,” I don’t see any nodes to edit or trim. Is it because I don’t have the shapes aligned well enough?

Tessellation.lbrn (20.2 KB)

The most likely problem is that your square is a “primitive” object in LightBurn, meaning it’s ‘instructions to build a square’, not ‘a square’, so you have to Convert to Path in order to be able to node edit it.

1 Like

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.