> On 3 Feb 2017, at 21:14, Todd Pierce <[email protected]> wrote:
> 
> Gorgeous Stuff Christophe,
> 
> I may be a bit confused here, but it may not address the (live) command-line 
> generation of geometry.  I was looking into what McBain was doing with 
> FreeCAD, but it looks like even what you're doing McBain, is scripting.  
> Correct me if I'm wrong, but this is the same drawback I'm encountering with 
> Gmsh.  Gmsh won't accept piped input either. 
> 
> I'm looking for a package that can display graphics as the commands arrive at 
> its input pipe.  Yes, this is weird, but I'm trying to embed the entire 
> multi-phyics suite of tools, including the generation of geometry, into a 
> *live* pipeline.  This is a natural language processor I am developing, so 
> the user (me) will require interactivity with the whole process.  Do you guys 
> understand what I'm trying to do?  Notice that BRL-CAD does exactly this, in 
> a fashion quite similar to Gnuplot, where the graphical output is displayed 
> as commands arrive at its input pipe,

As scripts can be executed in Gmsh command by command, you can definitely 
create a pipe to get an interactive system.

Here's a working example where we create a separate interactive command line 
program (like gnuplot) that simply feeds in scripting commands to Gmsh: 
https://onelab.info/svn/gmsh/trunk/utils/solvers/c++/interactive.cpp. You can 
easily create a similar driver that would use a pipe.

Christophe



> though I have no idea if BRL-CAD can really output the right file type for 
> meshing, or even if you experts would advise against BRL-CAD because it's too 
> primitive for other reasons.
> 
> So, McBain, did I miss your point or can FreeCAD be truly interactive from 
> the command line?  (or in this case, its pipe)
> 
> And Christophe, since you're obviously deep into these types of software, do 
> you have any suggestions?
> 
> -Todd . 
> 
> On Fri, Feb 3, 2017 at 6:49 AM, Christophe Geuzaine <[email protected]> 
> wrote:
> 
> As a little teaser, just to let you know that I'm coding a direct interface 
> to OpenCASCADE CAD creation right in .geo files. This will in particular 
> support automatic creation of conform interfaces when you fuse solids, in 
> order to handle internal boundaries.
> 
> Here's what the scripts will look like (not everything is in the SVN trunk 
> yet):
> 
> SetFactory("OpenCASCADE");
> 
> Mesh.Algorithm = 6;
> Mesh.CharacteristicLengthMin = 0.4;
> Mesh.CharacteristicLengthMax = 0.4;
> 
> R = 1.4;
> s = .7;
> t = 1.25;
> 
> Block(1) = {-R,-R,-R, R,R,R};
> 
> Sphere(2) = {0,0,0,R*t};
> 
> BooleanIntersection(3) = { Volume{1}; Delete; }{ Volume{2}; Delete; };
> 
> Cylinder(4) = {-2*R,0,0, 2*R,0,0, R*s};
> Cylinder(5) = {0,-2*R,0, 0,2*R,0, R*s};
> Cylinder(6) = {0,0,-2*R, 0,0,2*R, R*s};
> 
> BooleanUnion(7) = { Volume{4}; Delete; }{ Volume{5}; Delete; };
> BooleanUnion(8) = { Volume{6}; Delete; }{ Volume{7}; Delete; };
> BooleanSubtraction(9) = { Volume{3}; Delete; }{ Volume{8}; Delete; };
> 
> 
> <wiki.png><coool.png>
> 
> 
>> On 2 Feb 2017, at 23:28, G. D. McBain <[email protected]> wrote:
>> 
>> 
>> 
>> Sent from ProtonMail, Swiss-based encrypted email.
>> 
>> 
>>> -------- Original Message --------
>>> Subject: [Gmsh] BRL-CAD for Geometry?
>>> Local Time: 2 février 2017 4:07 PM
>>> UTC Time: 2 février 2017 05:07
>>> From: [email protected]
>>> To: [email protected]
>>> 
>>> Hi All, 
>>> It's me again, wondering how I should go about integrating a command-line 
>>> geometry package into OneLab (or some other chain of multi-physics tools).
>>> As I've mentioned before, although there is no shortage of tools to do 
>>> meshing, finite element analysis or CFD and so forth, there is no simple 
>>> way to build geometries from the command line. 
>>> 
>>> Has anybody ever used this BRL-CAD/Mged command line CAD package?  It 
>>> doesn't look bad, but I do have concerns about it exporting to formats that 
>>> these meshing and physics programs use.
>> 
>> In the past I have used BRL-CAD's mged command-line tool to create 
>> geometries for subsequent CFD simulations.  I used BRL-CAD's g-stl 
>> command-line tool to export a triangulation of the bounding surface in STL 
>> format.  Gmsh can read this in.
>> 
>> More recently though I'm using FreeCAD which can be scripted in Python and 
>> so run from the command-line.  Besides STL, this also outputs IGES, STEP, 
>> and BRep, which can contain more information that STL.  Gmsh reads all four 
>> formats.
>> 
>> OpenSCAD is an excellent accompaniment to FreeCAD too, especially via Solid 
>> Python.
>> 
>> Often my workflow looks like FreeCAD -> Gmsh -> FreeFem++ -> (Gmsh or 
>> pandas), with the whole thing run from a single SCons build file.  No GUIs, 
>> except for preliminary exploratory work.
>> 
>> I haven't looked into OneLab yet.
>> 
>> _______________________________________________
>> gmsh mailing list
>> [email protected]
>> http://onelab.info/mailman/listinfo/gmsh
> 
> -- 
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science 
> http://www.montefiore.ulg.ac.be/~geuzaine
> 
> Free software: http://gmsh.info | http://getdp.info | http://onelab.info
> 
> 

-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine

Free software: http://gmsh.info | http://getdp.info | http://onelab.info


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