python-brlcad-tcl

So far this is a small subset of the brl-cad primitives with some notion of object-oriented design, being emitted as tcl scripts that mged can directly process into database (.g) files. Requirements are Python and brl-cad.

An example of a 28BYJ-48 stepper motor, run with:

• # git clone this repository
• cd python-brlcad-tcl
• python -m examples.motor_28BYJ_48__example output.tcl
  • note that motor_28BYJ_48__COMPLETE1.r here is the 'region' that was created at the end of the motor's init function, it is a special type of combination that 'instantiates' all of the non-region 'object definitions' (primitives and combinations).
• meshlab output.stl

Multi-part example

The multi-part example shows how to use two python-brlcad-tcl objects (including motor_28BYJ_48__example.py). In addition to emitting the tcl script, it runs mged to create a new geometry database, and then converts that to an STL.

To view the resulting (.g) file in mged:

• # git clone this repository
• cd python-brlcad-tcl
• python -m examples.multi_part_example.py multi_part.tcl
• mged multi_part.g
  • (if you don't have meshlab installed, you could comment out the line starting with brl_db.save_stl to save some run-time time) I was running this example then opening the resulting (.STL) file in meshlab (because I don't know how/if mged has a real-time raytracing display mode) :
• meshlab multi_part.stl

Example of slicing a model and exporting to individual STL files:

Looking at the stack of STL files emitted:

Looking at the raster output, with greyscale output option:

Looking at the raster output:

Developers section

Adding support to python-brlcad-tcl for new operations or shapes/primitives

If it is an mged command

• find the usage syntax - https://brlcad.org/wiki/MGED_Commands
• add a new method that users will use to call the new feature from their scripts
• code the method to use string-formatting, then append it to the self.script_string_list object

Conventions

• name = self._default_name_(name)
  • this will do a few things
  • checks if the name is empty-string or None
    • if so, then uses the inspect module to learn the caller-function name, and uses that function name as a "new name"
  • checks if the name is in a lookup-table of already-used names
    • if so, appends a number to the name, then adds this name to the lookup-table
• return name
  • return the name of the final object or primitive so the users can use it if they want