Set properties recursively

[petrikvladimir]

This PR allows modifying member variables of the object, examples:

obj._set_property('material.color.b', 1)  # change only the blue channel of the color
obj1._set_property('material.color', [0, 1, 0]) # change the color of the material
obj1._set_property('material.opacity', 0.5) # change the opacity of the material

How it works:

• it splits strings based on dots to access internal variables, e.g., 'material.color.g' results in accessing variable 'g' of object this.object.material.color
• if the accessed object is of type color and the value is an array, use set.RGB()
• if the accessed object has a function set, use it to set the properties
• otherwise, use the assignment operator to change the value

[jwnimmer-tri]

Thanks for your interest!

We recently did something similar in https://github.com/meshcat-dev/meshcat/pull/177. Please take a look and see if it helps you out.

If there's still more to be done, please rebase this onto the latest master (or open a new pull request).

If not, please let us know and we can close this PR. Thanks!

[jwnimmer-tri]

Closing hoping that #177 was enough. If not, feel free to re-open / open a new PR with a new take.