[x3d-public] coord = NULL ?

[Andreas Plesch]

X3DComposedGeometry based nodes have a coord field which is NULL by default:

https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD/Part01/components/rendering.html#X3DComposedGeometryNode

But the spec. language does not spell out what a browser should do
with a NULL value for the coord field, in contrast to other fields
like color or normal.

It may seem nonsensical to have a geometry node with null coordinates
and therefore deemed outside the scope of the spec. But as it is an
in,out field, coord may be updated, and an initial NULL may have then
use cases. So a NULL value should at least generate no fatal error,
and probably no warning. Are there other aspects to consider ? Should
there be a difference between a NULL coord field, and a default
Coordinate node with an empty array for its point field ? It seems
not.

It seems self-evident that there should not be any rendering activity,
and that routing through other fields should still occur while coord
is NULL.

It may be fine to leave behaviour to browsers with the expectation to
do something sensible.

Andreas
-- 
Andreas Plesch
Waltham, MA 02453