Bug Report: 3 Object Circular Array Won’t Center Properly

Bug Description:
When creating a circular array with exactly 3 objects using the Arrange > Circular Array tool in LightBurn v1.7.08, the resulting array does not center properly. The generated pattern is visually off-center, even though the pivot and spacing settings are correct.

Steps to Reproduce:
1. Select any shape or object.
2. Go to Arrange > Circular Array.
3. Set the total number of objects to 3.
4. Apply the array.
5. Use Arrange > Move to Page Center.
6. Compare it to another, similarly sized object that’s already centered on the page.

Expected Result:
The 3-object array should be spaced evenly and centered on the page like any other grouped shape.

Actual Result:
The array is noticeably off-center, especially apparent when compared to other centered objects. This indicates that the array geometry is not calculated correctly for 3 items.

Workaround:
A reliable workaround:
1. Create a circular array of 6 objects.
2. Delete every other object.

This maintains proper spacing and centers correctly.

System Info:
• LightBurn version: 1.7.08 (stable)
• OS: Windows 11
• Laser type: Gweike G2 Pro 30W
Fiber Optic Engraving Machine

1 Like

Good job, this is how a bug should be reported. :nerd_face:

I can’t reproduce this given your steps. I also don’t get a different behavior with the workaround method.

Could this be because you’re expecting the “center” of the result of the array to be centered on a figurative circle around the array rather than as a rectangle of the resulting 3 shapes? Note that the center of a selection rectangle for 3 even spaced shapes is not necessarily equidistant from the center of each shape.

Review the following:

  1. the black circles are even spaced apart
  2. the blue rectangle represents the selection area of a group of the 3 black circles
  3. the red circle is the geometric center of the rectangle
  4. the red circle is not equidistant to the center of each black circle
  5. all of these statements are true concurrently
2 Likes

Thank you for your response.
In general, I see your point that a 3 (or odd#) object circular array, enclosed by a selection box, and centered will not result in each object’s center being equidistant to the centering point.

Hopefully you saw that when you tried reproducing the (supposed) problem I reported :slightly_smiling_face:

It was a surprising result for me, since I was so use to the object array always being perfectly centered. I guess I just had never used the tool to create an odd number of objects in the array.

Anyway… for anyone trying to get an odd number of array objects centered, I think my workaround should be helpful (i.e., since just doubling the Odd# of objects will always yield an Even#, which should center properly).

Thank you for your kind help,
Cheers!
-:-

1 Like

I think this was just luck because you are have an even number of sides in the bounding box. Had you used a triangle for the bounding box (odd # sides), it would have centered as you expected. Had you used a circle for the bounding object (infinite sides), any number of circles would have centered like you expected.

I instinctively use a circle boundary for any circular layouts.

Thank you for your response.

What you wrote does sounds logical to me.
I wasn’t aware that you can change the bounding box used when selecting an object to anything other than a rectangle aligned with x&y axes. Is there an easy way to do that (I’m still learning the ins&outs of LightBurn)?
Best Regards,
-Duke53
-:-

Sorry, we are talking about 2 different things here. You are talking about the Selection box. I am thinking more like a copy along path thing. My work with Lightburn is a lot of hit or miss. I hardly use LB to its full potential. We both need to hope those all day long users jump in and clear up the mysteries.

I do seem to remember you have the option of using a rectangular or circular pattern for the Array tool. That may be where I got my “circle”.

Thanks for the feedback!

I wish us both good luck in exploring the capabilities AND mysteries of LightBurn​:upside_down_face::victory_hand:

Cheers!

-:-

1 Like

I just opened the project above with Beta-15 and the scale and origin are exactly where and what they should be. Apparently, my pix was from an early-early version of MillMage.