Python Topological Namer/Tracker

[DeepSOIC]

Namely, I'll need to expose the Modified/Deleted/Created faces from any given OpenCascade operation via the TopoShapePy implementation.

https://github.com/FreeCAD/FreeCAD/pull/868

[ezzieyguywuf]

Sweet! I'll rework my example to use these

[ezzieyguywuf]

I have updated my example to use @jnxd's GSoC history framework. It works great now, with no 'cheating'! In other words, in my original example I had to hard-code which faces got modified/deleted etc., but now I am able to do it all programatically.

I realized that it may be helpful to give a step-by-step on how to run my example as well as provide a screenshot that shows what's going on. Here it goes:

1. Download PyTopoNamer

   Code: Select all

   $> cd ~
   $> git clone https://github.com/ezzieyguywuf/PyTopoNamer.git

2. Edit the `path` variable in the `~/PyTopoNamer/FreeCAD_scripts/testNamer.FCMacro` test Macro. In our example, it should be set to `'~/PyTopoNamer'`
3. Compile a copy of jnxd's tnaming-pr branch
4. Open FreeCAD (which you just compiled)
5. Run the macro. You can either select it from the gui or perform the following in the Python console. If you do it this way, all the objects will remain available in the python console for further inspection/tinkering.

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   >>> myFile = '~/PyTopoNamer/FreeCAD_scripts/testNamer.FCMacro'
   >>> execfile(myFile)

freecad_toponamer.png (16.42 KiB) Viewed 2088 times

Above is a screenshot of the generated solids after running the script. Here is what you are seeing:

• The red solids show the current FreeCAD implementation of Topological Naming. You can see that in the second solid (from the left) the Chamfer has moved when FreeCAD recomputed the solid (after the cylinder was shortened)
• The blue solids show the PyTopoNamer implementation of Topological Naming. You can see that in the second solid (from the left) the Chamfer is still on the same Edge. That is because I have a robust way of referencing that Edge
• The third solid for both cases is the fusion object that was used to create the Chamfer. I have included these in order to show that there is no funny business going on: both the red and blue fusion objects will show (via the Report View) that the "edge to be chamfered" is named "Edge3".
  The original Edge, in case you are wondering, was named "Edge10". This is why the FreeCAD implementation fails

Note: I did not use any of the Part::Feature objects because then all the recomputes are done automatically by FreeCAD. Instead, I re-implemented the Part Workbench's Part::Feature object in order to, as best as I could, re-create how the Part Workbench handles and recomputes solids. This way, I was able to intercept the recompute and use my PyTopoNamer instead. This was easier (kind of) than re-writing or hacking the recompute in C++.

I think, for now, I am going to take a break from the PyTopoNamer and begin work on what I'm calling CppTopoNamer. It will be the same as the Python prototype but written from the ground up in C++. This may take me some time, as I am new to unit testing in C++, and I feel it is imperitive that this component have robust unit testing.

[chrisb]

That is very promising!!

[fosselius]

This is truly awesome! makes me cry when i think of how many hours i have spent fighting issues related to topological naming... Keep it up!

[cox]

Tears in my eye as well, be weary you confused references, @ezzieyguywuf is coming to eradicate you! Your days are numbered.

[ezzieyguywuf]

Glad people are excited! The CppTopoNamer is taking form slowly, as i said in an earlier post I'm not familiar at all with C++ and unit tests so it's taking a while to get rolling - I have made progress though. Right now I'm trying to figure out a good way to mock the OpenCascade classes, i.e. TopoDS_Shape.

[triplus]

Good to see progress!

[apeltauer]

Hello all,

at the beginning thanks to everybody who is working on FreeCAD an making this wonderful piece of software work...

@ezzieyguywuf i am interested in how you are realizing the unit tests in c++. What framework are you using?
I have no clue how a unit test with c++ should look like for FreeCAD. I would try to use gtest, but i dont know what the commen way in FreeCAD is...

Also i havent found the answer in the forum or the dokumentation....
I hope someone can lead me to the answer...

Thanks...

[ezzieyguywuf]

@ezzieyguywuf i am interested in how you are realizing the unit tests in c++. What framework are you using?
I have no clue how a unit test with c++ should look like for FreeCAD. I would try to use gtest, but i dont know what the commen way in FreeCAD is...

I have made some small progress on this. You can see my work here on my github. You'll want to start with SolidManager_PrimitiveTester.cpp which shows some very basic tests for the Topological Namer that I'm working on.

You'll also want to take a look at IEdge.h, IFace.h, and ISolid.h. These three header files describe a generic interface to a topological Edge, Face, and Solid respectively. The idea is that my Topological Namer (and really, any component within FreeCAD in general) does not need to know specifically about TopoDS_Edge, TopoDS_Face, nor TopoDS_Solid from OpenCascade. Rather, what the Topological Namer needs to know is about an interface to these entities.

So, what I have right now is a very very basic interface for these - essentially, only exposing the functionality that I need for a basic Topological Namer test. You'll notice in my test/include folder I've defined some classes (i.e. Mock_Edge.h) which implement these headers. These 'mock' classes implement the respective interfaces in a very naive manner: for example, for checking equality they accept an integer to identify themselves and check if this value is equal. This works well for my basic tests - you can see how I use these mock classes in the MockObjectMaker helper class.

Anywho, hopefully this helps a little bit. Let me know if you have any questions, I haven't really gotten around to documenting this code yet.