Fill rectangles distorted in preview and job

Hello, I drew some rectangles in Lightburn, and for some reason they engrave as shown in the preview:

The first two rectangles are not rectangle.

Fill settings are as follows:

Changing only the speed for each rectangle. I have tried changing fill groups together, individually etc.

How do I ensure all rectangles are engraved correctly?


That’s probably a very small rounding error in the math. I’ll have a look and see if I can figure out why that’s happening.

Awesome, thank you. In case it helps you replicate the issue, they are 50x10mm rectangles placed at (100,100), (100,120), (100,140) etc. Latest version of Lightburn.

This is fixed, and will be in the next release.

The problem is that 32-bit floating point math can’t perfectly represent ‘Pi’. When accounting for origin and scanning orientation, vectors are often rotated by 180 degrees, which ends up being 3.14159274 instead of 3.14159265 radians. It’s microscopic, but it makes lines angle just a tiny tiny bit, and causes a little of the shape to slip outside the bounding box for rastering. I’ve added one micron of ‘slop’ to the bounds, and that fixes it.

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Aha, the rectangles came out nicely on the 64-bit version of Lightburn. Thank you for the quick response!

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