Tools are unusable if any unserializable objects are in the scene

[Jordan Santell]

Adjacent to #16, any scene with an object that cannot be serialized (WebGLRenderTarget, DataTexture, InterleavedBufferAttribute) throws an error during serialization, preventing any information from the scene being parseable without reimplementing toJSON(), which is something I'd like to avoid.

While a stretch goal would be to somehow interpret these dynamic objects, the minimum needed in order for a scene to be debugged would be for these unserializable objects to return stubs (e.g. { width, height, type } for WebGLRenderTarget maybe), or less preferably, skipped during serialization (I'd rather be aware of the objects and not be able to represent them fully).

Requires a handful of fixes upstream:

• InterleavedBufferAttribute.toJSON (mrdoob/three.js#17328)
• Handling dynamic textures (WebGLRenderTarget, DataTexture) (mrdoob/three.js#16816)
  • Related, scene.background support #16, mrdoob/three.js#16764
• ParametricBufferGeometry serialization (mrdoob/three.js#17381)

[Jordan Santell]

Fixed via heavy patching in ff968ce;

Test the following:

• InterleavedBufferAttributes
• DataTexture, WebGLRenderTarget as scene.background
• Parametric Geometry

Does not address in making all of these objects able to be deserialized, but at least provides some information, or stubbed data, rather than breaking the tools.

Viewing a render target's texture is still not doable (#4)