Warning about gl_InstanceID and uniform block (buffer?) object fields

[ibsusu]

Hello,

I've been doing some research about uniform block objects and instancing with OGL. Right now Geometry raises a warning for anything that's contained inside of a uniform block object. It also raises a warning for gl_InstanceID.

attribute vec3 position;
attribute vec3 offset;

uniform Group {
      uniform vec3 groupPos[10];
      uniform vec3 groupRotation[10];
};

void main() {
    vec3 pos = position;
    pos += groupPosition[gl_InstanceID]+ offset + groupRotation[gl_InstanceID];
    gl_Position = projectionMatrix * modelViewMatrix * vec4(pos, 1.0);
}

Secondly, on this line right here:

ogl/src/core/Geometry.js

Line 179 in 9dae6ba

if (attr.needsUpdate) this.updateAttribute(attr);

It chokes on gl_InstanceID. I just did a check to see if it's that name and bail out if it is.

If I make a PR that provided better support for instancing and Uniform Block Objects would that be ok? The reason I'm interested in doing it this way is because I can get really good performance and modify groups of instances of different geometries with a single change. BTW this code won't work on Firefox atm. Firefox doesn't support vectors in uniform block objects for some reason. uniform vec3 groupPos[10];. Safari and Chrome are fine though.

If there's another way to do this let me know please.

[gordonnl]

UBO support would be an excellent feature for OGL, absolutely! Especially with Webgl2 starting to gain universal support with the addition of safari.
At the moment there would still be a need to create a WebGL1 fallback, however I'm still interested to see your implementation in any case!

[ibsusu]

I'll need a bit but this is definitely on my todo list. Close this if you want to remove clutter.