How to optimize dxf path

[njourdane]

I have a dxf file not optimized, in a sense that there are many useless moves:

On the image above, only circles and the contour belongs to the actual dxf, other lines are just moves.

I wanted to avoid this, so I wrote a basic path optimizer for ezdxf:

It's not perfect, but before to improve it I wonder if there is a built-in ezdxf feature to do this.

If not, I can improve and publish my script as an ezdxf addon.

[mozman]

Thank you for your offer, but in my opinion this is a task for a human using an interactive CAD application and cannot be solved by an automated function call of a library like ezdxf.

Even with a simple task like this, it's hard to tell what the "correct" result is:

[njourdane]

Hmm, Maybe I am misunderstood. I don't want to remove "cuts", I want to reduce "moves" (or, in other words, reorder dxf entities). So in your example above, the result will be the original file.

When I import a dxf file to the laser cutter I use, the tool doesn't optimize paths and takes more time to move than to actually cut. I'm not going to fix this by hand, because is a huge waste of time and it can be done automatically.

[mozman]

Shouldn't this be done by the cutter software? In any case, this is a very specific problem for laser cutting and only marginally related to the DXF file format itself (the graphical entities look the same in a CAD application).

BTW: CAD applications order the entities by ascending handle values by default. The entity order can be changed by the header variable $SORTENTS or adding a SORTENTSTABLE entity to the layout. Third party software often ignore this feature, most likely also the cutter software you are using.

• example for altering the redraw order: https://github.com/mozman/ezdxf/blob/master/examples/redraw_order.py
• docs for the reorder module: https://ezdxf.mozman.at/docs/reorder.html