Improve Rendering Script

[lalalune]

This PR aims to improve the data generation pipeline in the following ways:

• Add significant documentation
• Add flag to switch from Cycles renderer to Eevee renderer, Cycles is still default
• Add flag to adjust num_views
• Move all scene setup, lighting and other repeat functional into a Blender scene which is loaded instead -- one for Cycles, one for Eevee -- this makes debugging and modifying scene settings much more interactive
• Switch lighting scheme from massive area light to primarily HDR image-based lighting
• Move dataset selection to an overridable JSON file, which allows for more fine-grained path control and custom datasets
• Retain same defaults as before

Please let me know if this works for your needs or if you'd like to change / reduce scope on anything!

Please note, if you accept the general pattern of this PR I would like to give the code a once over and make sure everything is really perfect before it goes into the codebase. Thanks!

[TREE-Ind]

Nice work, we were able to get ShapenetV2 rendering with Blender 3.3 using your PR :D

[muxizju]

@lalalune I get errors when using this pr, it seems the blender can not recognize the config file "eevee_renderer.blend". my blender version is 2.9.0, is it not matched ?

[lalalune]

@muxizju I saved the project in the most recently stable Blender download (3.3?) so it might be a version conflict there

[muxizju]

@muxizju I saved the project in the most recently stable Blender download (3.3?) so it might be a version conflict there

that's right, use version 3.3 can solve it. While it seems the EEVEE engine can not work on terminal-only linux, there is an error“Unable to open a display Aborted (core dumped)”. It works well with CYCLES on the same machine