Part Geometry Extensions

[paullee]

Download the zip from here right?

https://github.com/abdullahtahiriyo/Fre ... _extension_

Hope I can compile it again

[DeepSOIC]

...

Thanks for your elaborate answer.

Being able to alter the way geometry behaves can be useful. I can imagine one could hack in spiral support into sketcher, for example. Or, I wanted to do a sketcher-powered gearbox constructor tool (but I won't, most likely), and displaying an actual gear instead of just the driving circle could be kinda cool.

Also, quite some time ago I had an idea to expose geometry and constraints as DocumentObjects contained by sketch as a group. However, it hits exactly the same recompute-system related problems as assemblies do, so it requires revolution of recompute machinery. It also puts quite some strain onto FreeCAD, so sketches with thousands of elements will become completely impractical (although enormous sketches isn't a good idea IMO, but people are doing it again and again anyway).

BTW, I wouldn't consider compatibility for opening new files with older version a big advantage. Yes, for users it's important. But if it gets in a way of FreeCAD improvement - screw it.

[abdullah]

...

Thanks for your elaborate answer.

Really thanks to you for putting forward an alternative solution. You are obviously working a different angle and it is good that we look into these details.

Being able to alter the way geometry behaves can be useful. I can imagine one could hack in spiral support into sketcher, for example. Or, I wanted to do a sketcher-powered gearbox constructor tool (but I won't, most likely), and displaying an actual gear instead of just the driving circle could be kinda cool.

With the sketcher current architecture, if I wanted support for spirals, I would have to provide support for spirals in Part::Geometry, teach the sketcher's SketchViewProvider to draw spirals, create commands to create spirals, implement a solver interface for spirals (either a complete one, or an incomplete one like the one of the b-splines),... in all this, having a Sketcher::Geometry or a Part::Geometry does not change anything.

I understand that you want to be able to alter the way geometry behaves by encapsulating existing geometry into a new Sketcher::Geometry. But if I am understanding it well, such encapsulation may only serve from an OCCT interfacing point of view, meaning that solver would still need to be provided in GCS, the geometry added to the SketchViewProvider for drawing for example.

You may tell me that you do not like the current Sketcher architecture, where functionality is spread around, for example, that the SketchViewProvider is responsible for displaying just about everything, and that it would be better to have separate ViewProviders, like in the case of Part Design features. This I understand. This could also allow you to selectively display the driving circle or the actual gear (I guess you refer to the 2D representation with the teeth).

However, Sketcher::Geometry, which in such a case would be a documentobject, is just a tiny bit of the puzzle you are presenting. This would be a major Sketcher revamp affecting all areas of the sketch, solver, internal architecture, solver interfacing,... it would basically amount basically to rewriting the sketcher workbench.

While I can agree many parts of the current sketcher could certainly benefit from a big "refactoring"/"reimplementation", we are really talking here about a huge investment. It is just a new workbench. One that I am not sure we could afford with the resources available. Think of how PartDesign, with at least three times more resources, managed to stop FreeCAD releases for a couple of years.

Because of the disruptive characteristic, if we were to introduce something like this, it would probably make sense to write a new workbench and enable to import sketches into that new workbench. I mean, I am not against it. It may be good in the long run and even fun.

BTW, I wouldn't consider compatibility for opening new files with older version a big advantage. Yes, for users it's important. But if it gets in a way of FreeCAD improvement - screw it.

Everything is a tradeoff. For sure backward compatibility may be sacrificed to introduce an improvement. However, I think the cost-benefit has to be clear from the outset.

[abdullah]

I have been revising the concept and I basically end up changing how it works and reimplementing it.

This is the new branch.

This is rebased as of today, so it also includes other improvements to the Python interface that were just merged (like clone() support).

NOTE: I know there is a bug that crashes FreeCAD. I am trying hard to find it.

1. Named extensions

Now extensions, apart from a type, have a name (extension name). The combination of type and name is unique. There is only one such extension. But one can have several extensions of the same type with different names.

2. Extend Geometries using default extension types

Part provides some default extension types, which can be used to store information in a geometry without creating a custom extension. The default extension types implemented as of now are:
- GeometryIntExtension (long int/Py::Long),
- GeometryDoubleExtension (double/Py::Float),
- GeometryBoolExtension(Bool/Py::Boolean),
- GeometryStringExtension(std::string/Py::String).

So if your python macro/wb requires to associate to a geometry a string and three doubles, you can create:

Code: Select all

>>> geo0.setExtension(Part.GeometryStringExtension("myrandomstring","ext1"))
>>> geo0.setExtension(Part.GeometryDoubleExtension(3.5,"myval1"))
>>> geo0.setExtension(Part.GeometryDoubleExtension(5.5,"myval2"))
>>> geo0.setExtension(Part.GeometryDoubleExtension(7.5,"myval3"))

So you get:

Code: Select all

>>> geo0.getExtensions()
[<GeometryStringExtension ('ext1', myrandomstring) >, <GeometryDoubleExtension ('myval1', 3.5) >, <GeometryDoubleExtension ('myval2', 5.5) >, <GeometryDoubleExtension ('myval3', 7.5) >]

3. Extend Geometries using a custom extension

Currently custom extensions (a single extension having a plurality of different values of different types) must be writen in c++.

4. Geometry Interface

A Part::Geometry is a container of extensions, from Python you can:
- List the extensions:

Code: Select all

>>> geo0.getExtensions()
[<GeometryStringExtension ('ext1', myrandomstring) >, <GeometryStringExtension ('ext2', myrandomstring2) >, <GeometryIntExtension ('extnumber', 5) >, <GeometryBoolExtension ('geocoolness', True) >, <GeometryDoubleExtension ('myval1', 3.5) >, <GeometryDoubleExtension ('myval2', 5.5) >]

- Set a new extension:

Code: Select all

>>> geo0.setExtension(Part.GeometryStringExtension("myrandomstring","ext1"))
>>> geo0.getExtensions()
[<GeometryStringExtension ('ext1', myrandomstring) >]

- Remove an extension (by type or by name, if they are several extensions all of them are deleted):

Code: Select all

>>> geo0.deleteExtensionOfType("Part::GeometryStringExtension")
>>> geo0.deleteExtensionOfName("myval2")

- get an extension (by type or by name)

Code: Select all

>>> geo0.getExtensionOfName("myval1")
<GeometryDoubleExtension ('myval1', 3.5) >
>>> geo0.getExtensionOfName("myval1")
<GeometryDoubleExtension ('myval1', 3.5) >

- modify a preexisting extension. If the extension has the same type and name, the preexisting extension is substituted by the new extension:

Code: Select all

>>> geo0.setExtension(Part.GeometryDoubleExtension(5.57,'Micleas'))
>>> geo0.getExtensions()
[<GeometryDoubleExtension ('Micleas', 5.57) >]
>>> ext1 = geo0.getExtensionOfName('Micleas')
>>> ext1
<GeometryDoubleExtension ('Micleas', 5.57) >
>>> ext1.Value=10.5
>>> ext1
<GeometryDoubleExtension ('Micleas', 10.5) >
>>> geo0.setExtension(ext1)
>>> geo0.getExtensions()
[<GeometryDoubleExtension ('Micleas', 10.5) >]

4. Default extensions Interface

- The interface is uniform, you can get/set the Name and the Value. This is an example for a GeometryDoubleExtension:

Code: Select all

>>> temp0 = geo0.getExtensionOfName("myval1")
>>> temp0
<GeometryDoubleExtension ('myval1', 3.5) >
>>> temp0.Value
3.5
>>> temp0.Name
'myval1'

Example session:

Code: Select all

>>> geos = ActiveSketch.Geometry
>>> geo0 = geos[0]
>>> geo0.getExtensions()
[]
>>> geo0.setExtension(Part.GeometryStringExtension("myrandomstring","ext1"))
>>> geo0.getExtensions()
[<GeometryStringExtension ('ext1', myrandomstring) >]
>>> geo0.setExtension(Part.GeometryStringExtension("myrandomstring2","ext2"))
>>> geo0.getExtensions()
[<GeometryStringExtension ('ext1', myrandomstring) >, <GeometryStringExtension ('ext2', myrandomstring2) >]
>>> geo0.setExtension(Part.GeometryIntExtension(5,"extnumber"))
>>> geo0.getExtensions()
[<GeometryStringExtension ('ext1', myrandomstring) >, <GeometryStringExtension ('ext2', myrandomstring2) >, <GeometryIntExtension ('extnumber', 5) >]
>>> geo0.setExtension(Part.GeometryBoolExtension(True,"geocoolness"))
>>> geo0.getExtensions()
[<GeometryStringExtension ('ext1', myrandomstring) >, <GeometryStringExtension ('ext2', myrandomstring2) >, <GeometryIntExtension ('extnumber', 5) >, <GeometryBoolExtension ('geocoolness', True) >]
>>> geo0.setExtension(Part.GeometryDoubleExtension(3.5,"myval1"))
>>> geo0.setExtension(Part.GeometryDoubleExtension(5.5,"myval2"))
>>> geo0.getExtensions()
[<GeometryStringExtension ('ext1', myrandomstring) >, <GeometryStringExtension ('ext2', myrandomstring2) >, <GeometryIntExtension ('extnumber', 5) >, <GeometryBoolExtension ('geocoolness', True) >, <GeometryDoubleExtension ('myval1', 3.5) >, <GeometryDoubleExtension ('myval2', 5.5) >]
>>> geo0.getExtensionOfName("myval1")
<GeometryDoubleExtension ('myval1', 3.5) >
>>> temp0 = geo0.getExtensionOfName("myval1")
>>> temp0
<GeometryDoubleExtension ('myval1', 3.5) >
>>> temp0.Value
3.5
>>> temp0.Name
'myval1'
>>> geo0.getExtensionOfType("Part::GeometryDoubleExtension")
<GeometryDoubleExtension ('myval1', 3.5) >
>>> temp0 = geo0.getExtensionOfName("myval2")
>>> temp0.Value
5.5
>>> temp0.Name
'myval2'
>>> temp0
<GeometryDoubleExtension ('myval2', 5.5) >
>>> geo0.deleteExtensionOfType("Part::GeometryStringExtension")
>>> geo0.getExtensions()
[<GeometryIntExtension ('extnumber', 5) >, <GeometryBoolExtension ('geocoolness', True) >, <GeometryDoubleExtension ('myval1', 3.5) >, <GeometryDoubleExtension ('myval2', 5.5) >]
>>> geo0.deleteExtensionOfName("myval2")
>>> geo0.getExtensionOfName("geocoolness")
<GeometryBoolExtension ('geocoolness', True) >
>>> geo0.getExtensionOfName("geocoolness").Value
True
>>> geos[0]=geo0
>>> ActiveSketch.Geometry = geos

[abdullah]

Just pushed some fixes. Maybe the bug is gone (or maybe not, that is testing for )

[abdullah]

Download the zip from here right?

To be honest with you, I would center in another part of the development until the geometry extensions get merged for two reasons: 1) Geometry extensions will allow you to have whatever you want to have, 2) It is likely that together or immediately after the geometry gets merged, I will include part of the Realthunders idea, which will most likely provide you with a sketch geometry id.

If you do not feel like waiting, of course, you may try to adapt the existing uuid, but it is not going to be straightforward (serialisation), I fear.

I can probably wait. There's plenty on the to-do list for the moment, anyway. All the same, I could use constraints as a proxy as an interim solution, if I really need to test that before geometry extensions are ready.

I think you are the ones interested in Geometry Extensions.

I think I have finished the development. It won't be merged before v0.19. If you want to try it you may download the PR below.

PR:
https://github.com/FreeCAD/FreeCAD/pull/1974

[paullee]

I think I have finished the development. It won't be merged before v0.19. If you want to try it you may download the PR below.

PR:
https://github.com/FreeCAD/FreeCAD/pull/1974

Downloaded and will try another 'heroic' compiling for me again

Thanks !

[Joel_graff]

I think you are the ones interested in Geometry Extensions.

I think I have finished the development. It won't be merged before v0.19. If you want to try it you may download the PR below.

PR:
https://github.com/FreeCAD/FreeCAD/pull/1974

I'll probably wait for it to show up in 0.19 at this point. I'm up to my eyeballs in other issues atm.

[paullee]

Seem compiled without error on Fedora 29, will see it run and test probably another weekend

[paullee]

Seem compiled without error on Fedora 29, will see it run and test probably another weekend

1. Named extensions

Now extensions, apart from a type, have a name (extension name). The combination of type and name is unique. There is only one such extension. But one can have several extensions of the same type with different names.

2. Extend Geometries using default extension types

Part provides some default extension types, which can be used to store information in a geometry without creating a custom extension. The default extension types implemented as of now are:
- GeometryIntExtension (long int/Py::Long),
- GeometryDoubleExtension (double/Py::Float),
- GeometryBoolExtension(Bool/Py::Boolean),
- GeometryStringExtension(std::string/Py::String).

So if your python macro/wb requires to associate to a geometry a string and three doubles, you can create:

Code: Select all

>>> geo0.setExtension(Part.GeometryStringExtension("myrandomstring","ext1"))
>>> geo0.setExtension(Part.GeometryDoubleExtension(3.5,"myval1"))
>>> geo0.setExtension(Part.GeometryDoubleExtension(5.5,"myval2"))
>>> geo0.setExtension(Part.GeometryDoubleExtension(7.5,"myval3"))

So you get:

...

Hi, your branch compiled in Feb, just go through the steps and it works as expected ! Thanks

Testing in Sketcher::SketchObjectPython and have some thought see if you can offer some comment:-


SketchObjectPython - Python generated geometries or User added geometries

Using SketchObjectPython object, the def execute() add some geometries to the object. User can 'manually' add geometry also.

Thinking to add a 'tag' for those geometries added by inherent method of the SketchObjectPython object, to distinguish those added by user.

Not sure what exactly each of below mean, wonder if GeometryBoolExtension or GeometryStringExtension ( "autoGenerated", Geometry ) or ( "userAdded", Geometry )

Thanks for any idea.


- GeometryIntExtension (long int/Py::Long),
- GeometryDoubleExtension (double/Py::Float),
- GeometryBoolExtension(Bool/Py::Boolean),
- GeometryStringExtension(std::string/Py::String).