adding _repr_png_ for ipython

[bollwyvl]

Motiviation

When using SolidPython in the IPython Notebook, it would be nice if just typing:

cube([1,1,1])

would draw the object. Additionally, it would be nice to have these images persist through to nbviewer.

Integration

This follows the approach from the IPython documentation to add a custom PNG renderer to OpenSCADObject, which everything the user sees appears to inherit from... thanks for that!

Implementation

The _repr_png_ basically shells out to openscad to generate a PNG, using two temporary files, then pushes the raw binary out. The notebook then stores this as base64 encoded data. It would be lovely to do some compression up front, but that would introduce icky dependencies...

Demo

Here is an example notebook:
http://nbviewer.ipython.org/gist/bollwyvl/dc849c324ba80bdce771

Future Work

When a suitable browser-based, repackageable STL renderer has been discovered, an _repr_html_ could be added/replace the png one. There would be the question of CDN vs. inlining.

Open questions

How would you like to handle configuration? The manpage for openscad has a number of lovely options, like colorscheme, image size and camera stuff... but not axes 😞. solid.openscad_params? I guess the "gold bricks" color scheme is fine for now.

[bollwyvl]

Hey great!

We've been doing a lot of thinking about notebook CAD recently. An
interesting first step here would be to create versions of the scad
classes (widgets) with eventful attributes (traitlets) that feed into a
automatically updated display of the current state of the model... This
would let solid tie into all kinds of interesting things, sliders, solvers,
etc. I think it could be done as a second layer of api, so

from solid.widgets import *

I'll take a hack at it when I'm not so slammed, but would be interested in
your thoughts about other directions for integration!

On 20:45, Tue, Aug 11, 2015 Evan Jones [email protected] wrote:

Merged #37 #37.

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