Problem was having too many concurrent workers opened at once. Garbage collection apparently works very slowly on workers. Solution was to close them manually, after model data is sent to main thread.
Also some progress with Blender scene exporter. Some scenes now export correctly, though monkey test scene got worse, even with less hacky code.
Diffuse map and ambient occlusion maps are now optional in normal map shader.
By default, both are disabled, so they need to be enabled explicitly like this:
uniforms[ "enableAO" ].value = true;
uniforms[ "enableDiffuse" ].value = true;
alteredq
Mr.doob