Exporting to DXF files with curves creates millions of points, how to rectify?

I created several files with a lot of curves and I exported as DXF for my waterjet manufacturer and it created a million points on the curves. I do like that Lightburn actually can export as DXF without breaking every point and with maintaining the same size but how to simplify the files so the manufacturer doesn’t spend hundr4eds of hours on their end processing the millions of points?

Two things to check for:

  1. Check Edit->Settings->File Settings. Is DXF Export Settings set to “Export Arcs”? If not, try setting that before exporting.
  2. Select your shapes, then Edit->Optimize selected shapes. That should allow you to optimize and reduce the number of points used to represent the curves.
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Thank you! I have sent some test files with convert arcs and a widened curve tolerance to my manufacturer and hopefully there is some breakthrough. I tried the optimize and it didn’t narrow down the points for my particular file but I will keep that in mind- good tip!


Some shapes export with a lot of line segments even with Export Arcs set to on.
In the example below, if the corners are square, the top arc is converted with minimal nodes.


Draftsight DXF import

If the square corners are converted to arcs, the DXF file segments the top arcs.


Draftsight DXF import with round corners replacing the square corners


That is really helpful! My files have no area for square corners so I am wondering how to simplify and see if I can create a square corner in my very curved files.

Can you upload an example Lightburn file that you are having trouble with short line segments when exporting from LB to DXF?

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Screenshot 2024-02-12 002354

Just posted one! Thanks for asking :slight_smile:

Can you provide your actual Lightburn file? If not, you could export either .SVG or .AI from Lightburn and see if your waterjet cutter can better accept them.

I just saw this! I am on it!
size11_RED_yellow.lbrn2 (254.5 KB)

I will also see if they can upload an SVG or AI file!

The Lightburn file has a lot of nodes before being exported to DXF or another format.

The circles are not true circle entities in LB. They are comprised of 4 quadrants, and the circle shape is slightly rotated.

Was the entire file created in LB, or a different program?

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The files were all created in lightburn.

I think that in the latest versions of Lightburn this is no longer the case, the circle is straight.

I will download the latest version and convert these to true circles.

Sorry wasn’t meant for you to download the latest version, it`s only a minor change in tool output.
I believe there is no node reduction doing that.
In my tests with shape optimization I was able to reduce nodes in almost 1/4 but @RalphU has more graphic experience and I think its better to wait for his solution.

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I tried to optimize but it didn’t seem to do anything on my end…


But if we slide the optimization sliders too far, we can (hypothetically) change the shapes a little.

You have a lot of short line segments in your file. Also, the circles are 4 different quadrants. If you create circle entitites in LB, and do not change them to paths, they export to DXF as a circle entity. I am not sure why LB creates short line segments for some arcs (even with export DXF arcs selected). I think some of it has to do with LB using bezier curves, and your waterjet company is probably using lines, arcs, polylines, and circles.

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I just changed all the circles to entities and made corners out of the slots to hopefully create arcs. Does this make a difference?
size11_RED_yellow_circle entity.lbrn2 (464.8 KB)

The circles convert correctly, but the rest of the entities convert to short line segments. In your situation, I think a CAD program that creates tangent arcs (polylines) along with the slots and circles is a better option to create DXF files for your waterjet cutting. I started doing it, but it is a lot of work :slight_smile:

Edit: 05-01-2024 — I finished it. I used all of the circles. I rebuilt the slots so they are “cleaner” in DXF. I redrew the Perimeters so they were tangent arcs. They deviate a little bit from the original, but I think they are OK assuming you have some tolerance. I attached the DXF and LBRN2 file. Maybe you can cut a prototype, and see if it is OK. If you want to check my work, just import the DXF file and put the data on the layers that you need. The perimeter of the first 6 parts are actually 3 different parts, just rotated 180 degrees.

Also, I just exported a DXF from the LBRN2 file that I created, and it is much “cleaner”. I am assuming that’s because I created tangent arcs in CAD, and LB can export them better.
size11_RED_yellow_circle entity_CLEANED_UP_DXF.lbrn (621.9 KB)
size11_RED_yellow_circle entity_CLEANED_UP_DXF.dxf (752.6 KB)

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