I worked on a project that used the OpenCASCADE CAD kernel, and our conclusion was that it still has a ways to go. We often got errors with boolean operations and the speed of operations was generally slow.
Are there better CAD kernels available as open source? What did you go with in the end?
Also note that there are nascent "F-Rep" kernels that may end-up replacing / supplementing the B-Rep kernels now used in solid CAD systems.
They allow you to represent lattices and gradient structures that are essentially impossible to do with B-Rep systems.
Looks like I've got a new CAD program for my dad! Dad downloaded and installed A9CAD and it absolutely filled up his computer with malware. He loves A9CAD, but every time he installs it I have to get a copy of MalwareBytes and disinfect the system. Looks like FreeCAD might be just what he needs!
A9CAD appears to be a 2D CAD drawing program, whereas FreeCAD is centered around 3D parametric modeling. They're different approaches to creating things. If you want a decent free 2D drawing package, try DraftSight, Or LibreCAD if you want open source.
Ah, I didn't realise. Thanks for the recommendations.
Looks like I've got a new CAD program for my dad! Dad downloaded and installed A9CAD and it absolutely filled up his computer with malware. He loves A9CAD, but every time he installs it I have to get a copy of MalwareBytes and disinfect the system. Looks like FreeCAD might be just what he needs!
According to another commenter, A9CAD is a 2d CAD software. If this is really the case, you should check out QCAD. It is a nice free and open source 2d CAD program.
I worked on a project that used the OpenCASCADE CAD kernel, and our conclusion was that it still has a ways to go. We often got errors with boolean operations and the speed of operations was generally slow.
Are there better CAD kernels available as open source? What did you go with in the end?
OpenCascade is pretty much the only open source CAD kernel. There is brlcad, but that can only do CSG.
We tried parasolid, then we got forced into using ACIS. We didn't really end up with much of a complete product in the end as this was government funded research.
How does FreeCAD compare to SketchUP? Does anyone know of a FOSS 2D drawing tool? I do a lot of pipe drawings (P&ID) and Visio is not ideal and AutoCAD is prohibitively expensive.
I haven't used it in a while but there is QCAD. It doesn't do everything that AutoCAD does by no means but they have been working on it for a while.
LibreCAD is a good QCAD near-clone that is open source.
Are there better CAD kernels available as open source? What did you go with in the end?
Also note that there are nascent "F-Rep" kernels that may end-up replacing / supplementing the B-Rep kernels now used in solid CAD systems. They allow you to represent lattices and gradient structures that are essentially impossible to do with B-Rep systems.
Do you have any examples of these? Lattices and gradient structures are cool, but the problem is it's difficult to actually make these structures. 3D printers can make these structures, but they only accept data in B-Rep. Not to mention the 3D printers that can make these structures have closed controllers and run with proprietary software. The AMF file format can actually represent these things[0], but no one uses AMF.
Another problem is how does a human actually design these structures? 3D gradients are going to be hard to visualize much less work with. In addition, why should we have a human design gradients in these structures in the first place? Why not have a computer do this?
FreeCAD is a 3D CAD tool with features and UI similar to Catia, SolidWorks or Solid Edge. With CATIA being the gold standard tool that is used in aerospace, automotive, etc industries. So FreeCAD is on a very great path. (It also highlights how important the UI is. Everyone who every used a 3D CAD tool, can use FreeCAD in no time. On the other hand, everyone who used a polygon based 3D modeling like 3DMax or Maya wil…
I just started to dive into FreeCAD as an Inventor alternative. (Are you talking about pre-Blender 2.5? If so, I agree. It was a challenge going from 3ds r4 and 3ds Max 2... Had to memorize hot keys and get used to a tile based layout. But once I did, I was fast. The ui was very different, but in a good way, IMHO. The 3D concepts are mostly the same. But post 2.5, everything is much more discoverable. You can search…
I agree. Blender has made a lot of progress with its UI recently. The nonstandard 'right click to select' is still a bit wonky for new users. I've tried teaching blender to a few people and they -always- have trouble getting used to the right click thing. I've been using blender for so long I could never make the switch to left click, but I still think a new default option would help grow the community.
Are there better CAD kernels available as open source? What did you go with in the end?
OpenCascade is pretty much the only open source CAD kernel. There is brlcad, but that can only do CSG. We tried parasolid, then we got forced into using ACIS. We didn't really end up with much of a complete product in the end as this was government funded research.
Wow, was this Darpa's iFab? I don't recognize you from your username but I wouldn't be surprised if we worked together in some indirect way. I had literally the same experiences and explored all those same kernels. ... We concluded that the issues with OpenCascade's Boolean operations were so baked into the code that they'd probably be better off with a total rewrite. From what we could tell digging in the code, they tesselate the BRep, do a boolean on the tesselations, and then try to match the results back to the input surfaces. This ended up with all kinds of nonmanifold surfaces, edges, and vertices, in addition to taking minutes to hours to return an answer, if it ever did return. One guy took a pretty deep dive into that code to try to figure if he could optimize it, and it was bad in so many ways, like it was doing something that required tons of triangles to be copied and reconstructed over and over. ... I'll give OpenCascade credit for one thing though, which is that an STL generated from a manifold input STEP or other file format will actually be a manifold STL (i.e. crack free etc to the level of assuming "identical" vertices will be bit for bit identical in the STL file). Try making even a trivial part into STL with Solidworks and I virtually guarantee that "identical" vertices will not be bit for bit identical. There will be cracks and you'll have to correct for them. I've never had that problem with OpenCascade. Whatever there tesselation algorithm is, it at least makes crack free results.
FreeCAD's constraint-based sketching is more of a competitor with SolidWorks and Pro/E.
When I used AutoCAD 20 years ago I know it had a constraint based add-on. Maybe all integrated in by now.
AutoCAD still has constraint functionality, but it's a watered down version compared to Inventor. As well as that - I could be wrong - but I think it's limited to two dimensions.
This is mostly 3D modeling, AutoCAD is more comparable to LibreCAD for 2D stuff
AutoCAD LT perhaps is the better comparison.
AutoCAD still does 3D. It's just the foundation for the MCAD BIM and Surface Modeling product verticals that dump a whole load of tools on top for those specific workflows.