Re: LANG: Re: Standardizing coordinate systems, units of measure

Gavin Bell (
Fri, 19 Aug 1994 14:27:54 -0700

>>From a technical aspect, I think such access would require VRML
>> to be able to calculate two different viewing vectors for a scene
and send
>> one view to one display(right) and one view to another

>this is a local viewer ( client ) issue, and thus has little bearing
>on the questions of the VRML structure itself.

Mostly agreed, but there does need to be a notion of the size of both
the viewer and the world being viewed so that the eye-separation and
focal distances can be set appropriately.

To simplify things and cover 96% of what people want to do, I think the
concept of 'viewer size' is all that need be specified in the VRML
file. Based on the size of the viewer (am I a God? A person? An
ant?), a viewers can set reasonable defaults for eye-separation, focal
distance, and walk/fly/movement speed. Viewers can also support
changing the defaults to cover the other 4% of what people want to do
(e.g. I want to move as slowly as an ant, but have eyes 10 feet
apart). (yeah, right).