[Cad] [CAD] Solvespace

[Matthew Keeter]

Here’s a more technical explanation of constraint solving in sketchflat (solvespace’s predecessor):
http://cq.cx/dl/sketchflat-internals.pdf

My constraint writeup is very exploratory and shouldn’t be taken seriously
(but there are neat interactive visualizations).

-Matt

On Nov 17, 2015, at 7:23 PM, Nancy Ouyang <nancy.ouyang at gmail.com> wrote:

> Based on group interest, this week we'll read about solvespace, which as of March 2015 has a native linux port. It's Brep based.
> 
> I'll throw out these links and if someone has input on any particular reading / activity for the reading group, let the list know -- otherwise I'll pick something tomorrow night.
> 
> Thanks,
> --Nancy
> ==================
> 
> Youtube demo: https://www.youtube.com/watch?v=2r8Y4tOeYZQ
> Source: https://github.com/jwesthues/solvespace
> Windows: http://solvespace.com/download.pl
> Linux: http://solvespace.com/forum.pl?action=viewthread&parent=574
> OSX: http://solvespace.com/forum.pl?action=viewthread&parent=586
> 
> Constraint solver as python library: https://github.com/BBBSnowball/python-solvespace
> 
> Brief description of Solvespace's constraint solver: http://solvespace.com/tech.pl
> 
> Matt's explanation of constraints: http://www.mattkeeter.com/projects/constraints/
> 
> Example of adding a new constraint: https://github.com/ruevs/solvespace/commit/9963d9bb25d1e17ed5d5bbe8cd42fc73c8326f7c (from http://solvespace.com/forum.pl?action=viewthread&parent=1005)
> 
> My friend's complaints about solvespace:
> 
> it seems like the solver might be mostly symbolic
> with some sort of parser to evaluate
> 
> well i need to look at the source
> but the equations should be numerically represented
> otherwise you spend most of your time parsing a large system rather than doing math
> even worth parsing is slow because it has lots of branches
>  
> might look at solvespace in more detail later, it at least sounds hopeful
> depends on whether the newton iteration is done on a matrix or by symbolically evaluating the constraints
> 
> ew solvespace stores constraints and jacobians as expression trees
>  
> if i really cared about this i would start rewriting the Expr and System classes of solvespace
> 
> ~~~
> narwhaledu.org, educational robots [[<(._.)>]] my personal blog, orangenarwhals

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