reduce building complexity and split into parts

[kfarr]

• reduce complexity of buildings (reduce the size and number of parts and buildings)
• reduce draw calls by merging geometries in blender
• create named parts for each building that can be referenced in A-Frame to construct larger blocks
• use some sort of optimization or compression scheme such as draco or meshopt / gltfpack

[kfarr]

Need to fix building scale issues:
https://blender.stackexchange.com/questions/57040/normalize-all-objects-scale-and-rotation-transforms

[kfarr]

That method worked to fix building scale. Appears to be 1 draw call per part (per building)? Test to be sure. The to implement cloning of buildings along road.

[kfarr]

Done with a40af12 however needs documentation and before/after stats comparison. Also writeup tickets for next steps (more building types, instancing?)

[kfarr]

Stats to compare before and after for performance
test city? http://localhost:8080/#https://streetmix.net/kfarr/44

// OLD combined model
Geometries - 999, Programs - 13, Textures - 299
Calls - 1575, Triangles - 444960
60fps
// UPDATED with 'psuedorandom' buildings from gltf-part
geometries 813, programs 13, textures 296
calls 885, triangles 452582
60fps

It cut draw calls in half and about same number of triangles, so keep this change!

[kfarr]

I tried with gltfpack and the -kn option but resultant gtlf part didn't display but it does display in gltf viewer, more debugging needed zeux/meshoptimizer#151

[kfarr]

Sticking with draco for now, this is done