Bridges with holes in them always fail, an idea for how they could be improved

[factoidforrest]

Is your feature request related to a problem? Please describe. When printing a bridge with a hole in it, which is a fairly common situation when printing bolt/screw holes, the holes cause the bridge to fail. The slicer simply prints the holes first, in midair, and they don't work, and it makes a big mess. Heres an example slice to give an idea:

Describe the solution you'd like However, it seems perfectly possible to print these structures in midair, with the right pattern.

Describe how it would work If the slicer first printed the bridges it could print that avoided the hole, it would have a much better structure to print the holes second. Forgive the MS-paint: In this cough drawing, imagine that the slicer first printed the red sections crossing the gap, then orange, then maybe green, and then finally printed the hole's outline, it would end up with a much better result in my opinion. This approach is a bit like a spider-web pattern.

I lack even the first bit of math skills to implement this, but I can see that it's possible. Thanks!

[me25542]

This would be nice to have, it would be like stepped geometry holes but better.

[factoidforrest]

@me25542 interesting technique that I wasn't aware of

https://shop3d.ca/blogs/news/3d-printing-tip-1-designing-better-3d-printed-holes?_pos=1&_sid=d69277192&_ss=r

That's a nice trick to essentially force the slicer to do what I'm describing, but still suboptimal when I think the slicer could do almost as well on its own with the right algorithm. Nice to know about for when I really need it, though.

As an alternative, apparently some folks also just include a one layer thick area without the hole and then print the hole on top and cut out the layer with a knife after.

These solutions serve well to demonstrate that it's a common issue.