Support for disabling positional tracking

[num3ric]

This is again needed for 360 images & video support because you don't want the user to move its viewpoint inside the virtual video sphere.

Yes you could make the sphere HUUUUGE, but it's not an ideal solution.

[notlion]

If disabling positional tracking isn't an option you could place your sphere at the HMD position. Might even be simpler to do it that way.