geometric constraint solver?

I'm trying to locate sample shown in Showroom/Demonstrations '2D constraints and dimensions'. Is it part of Advanced Samples Pack? Is geometric constraint solver part of Open CASCADE public version?

Rob Bachrach's picture

To my knowledge, there is no 2D constraint solver available for from OCC. The demonstration is misleading. When OCC docs refer to constraints, they are referring to methods of creation (like the ability to create a circle tangent to 2 curves). Most of these can be found in the GccAna module in the free code.

Most of the time, when referencing a 2D constraint solver, the one de-facto standard is D-Cubed (currently owned by Unigraphics). This is not free, but it is possible that there is an interface to OCC available.

Good luck

Robert M.'s picture

Thanks, I'm aware of 2D DCM.

I'm basically looking for open source or modest fee solution. When I found Open CASCADE I thought this is it, but I was obviously wrong. Anyway, since there is an animated example in a showroom ther must be sample somwhere. But where is it?

Alexey Rasskazov's picture

Hi guys,
In fact there is another vendor for constraint solvers - Ledas ( You can find all usual staff about the company and its products on the site. E.g. a sample test application for LGS 2D (2D ledas geometrical solver) called Lege'n'd is available for free download at the Ledas web-site. It was created with the Open CASCADE open-source framework. Hopefully it helps.

Hany Sherif El-Kerdany's picture

Thanks for the Info every body, i'm also looking for an open source 2D Geometric constraint solver hopefully written in c++ .. and that can be compiled on many platforms ..
Does any body know where can i find that? ..

Torsten Sadowski's picture


to my knowledge there is no open source geometric constraint solver. I've been looking for something like this for years. There are generic constraint solvers available like and there are geometry programs like DrGeo or in its most basic form (X)Eukleides. The geometry programs more or less seem just to define points and keep a design history for the other elements. If a point is moved the rest ist rebuild. This approach is parametric but not a true constraint solver. But, because constrained solvers do err in commercial programs this approach just requires some thinking beforehand and should then work.


Frank Langbein's picture

There is Meera Sitharam's DOF based Frontier at available under the GPL. It needs maple, though, last time I checked. Combing this with OpenCascade would be interesting, but also a lot of work.