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Hey, author of Fornjot here. > I do wonder what kind of limitations the author ran into with OpenSCAD Lack of bevels/chamfers, no way to refer to existing geo

Hey, author of Fornjot here. > I do wonder what kind of limitations the author ran into with OpenSCAD Lack of bevels/chamfers, no way to refer to existing geometry (to sketch something on a face and extrude that, for example), no constraint-based modeling, weird and limited language. Those are a few off the top of my head. I don't want to speak badly about OpenSCAD. It's obviously very useful to a lot of people, and I myself keep coming back to it for my own projects (Fornjot isn't ready to replace it). But there are many good reasons to want something else. > and why they decided building a replacement code-CAD program was the best way to go. What would the alternative be, in your mind? Trying to join the OpenSCAD project, saying "I want to change everything", would just be rude. I don't want to fork a big C++ project either, as I don't know the language very well and have no interest in learning it. I'm also not convinced that starting with a fork of something would be better, in the long run. There's value in looking at the problem with fresh eyes.

benhurmarcel 5y ago
> no way to refer to existing geometry (to sketch something on a face and extrude that, for example) How do you solve that in "code CAD"? I mean referring to a geometry that's a result of some previous operations, not one that you manually created.
- hannobraun 5y ago
  > How do you solve that in "code CAD"? I mean referring to a geometry that's a result of some previous operations, not one that you manually created. I've written down some preliminary thoughts here: https://github.com/hannobraun/Fornjot/issues/101#issuecomment-1027292274 https://github.com/hannobraun/Fornjot/issues/101#issuecommen... And let me emphasize, these are just preliminary thoughts. I can see cases where what I wrote there won't work, and I'm sure there are many more problematic cases I haven't thought of yet. There's still a lot of work to do before any of that even becomes relevant for Fornjot. I'll keep thinking about it in the background, but I don't expect to come up with a meaningful solution before I had a chance to really dive into the topic. CadQuery has its own approach, which I have yet to study in detail: https://cadquery.readthedocs.io/en/latest/selectors.html https://cadquery.readthedocs.io/en/latest/selectors.html

benhurmarcel 5y ago

> no way to refer to existing geometry (to sketch something on a face and extrude that, for example) How do you solve that in "code CAD"? I mean referring to a geometry that's a result of some previous operations, not one that you manually created.

hannobraun 5y ago
> How do you solve that in "code CAD"? I mean referring to a geometry that's a result of some previous operations, not one that you manually created. I've written down some preliminary thoughts here: https://github.com/hannobraun/Fornjot/issues/101#issuecomment-1027292274 https://github.com/hannobraun/Fornjot/issues/101#issuecommen... And let me emphasize, these are just preliminary thoughts. I can see cases where what I wrote there won't work, and I'm sure there are many more problematic cases I haven't thought of yet. There's still a lot of work to do before any of that even becomes relevant for Fornjot. I'll keep thinking about it in the background, but I don't expect to come up with a meaningful solution before I had a chance to really dive into the topic. CadQuery has its own approach, which I have yet to study in detail: https://cadquery.readthedocs.io/en/latest/selectors.html https://cadquery.readthedocs.io/en/latest/selectors.html