It was quite a pain - ArrayBuffers / Typed Arrays are fussy about byte alignment - but seems to be worth it.
Parsing times are down (modest gains for small objects / Firefox, bigger gains for large objects / Chrome, performance gains from 10% - 200%).
Also as a positive side effect, changing interleaved face arrays into uniform arrays seems to have helped a bit with gzip compression (about 6% smaller size for gzipped 526K Lucy).
A lot of things going on in this commit:
- added tangents computation for geometries
- mesh must have UV coordinates
- to be called explicitly once geometry is loaded like this: geometry.computeTangents()
- tangents are stored in Vertex objects
- quads are not solved properly (though workaround hack seems to work at least somehow, as far as each vertex appears at least somewhere)
- extended VBOs in WebGLRenderer to include tangent streams (when available)
- added "normal" shader to ShaderUtils (to be used with MeshShaderMaterial)
- Blinn-Phong with one directional and one point light (7 varyings gone, just one spare)
- normal maps are in tangent space
- displacement maps use simple luminance value (could be changed if better precision is needed)
- displacement mapping uses vertex texture fetch
- this requires GPU with Shader Model 3.0
- not currently supported in ANGLE
- for this, added "supportsVertexTextures" method to WebGLRenderer API, so that application can handle this
alteredq