ElevationGrid

["K.E. Moore" <mek@leicester.ac.uk>]

To GeoVRML Group

The specification of color values for the ElevationGrid node is rather
cumbersome. Two much more flexible approaches to colouring of the height field
would be:

1. a ColorRamp, such as many GIS use,  with specification of key height fields
and values and an interpolator to apply intermediate colours. This could be
similar in construct to the ColorInterpolator but using height fields instead of
a time switch.

2. a ColorIndex which specifies key values and colours that are then applied to
the grid as SFInt32 - categorical data. This would be extremely useful in applying
secondary data to the primary height field instead of computing the full SFVec3fvalue to correspond to each  height field. 
This is implemented as ColorByVertex for Line and Face Sets - why not for teh
ElevationGrid?

I have also been using texture drapes
 for this purpose but as individual VRML plugins handle the texture in
different ways the outcome is sometimes unpredictable.

Kate Moore
mek@le.ac.uk

Virtual Field Course
Dept of Geography
University of Leicester
Leicester
LE1 7RH
UK