question

[mbp]

> I am displaying some data points using VECT format. Can I represent
> these points as 'x' or '+' rather than the point itself. When large
> no. of points are represented, its not easy to distinguish between
> them if they are represented as dots.

It is possible to do this, but not using the VECT format.  You can
use the INST format to specify whatever geometry you want for the
points.   The general format for doing this is

    INST
    geom { < point.oogl }
    transforms
    1 0 0 0   0 1 0 0   0 0 1 0   x1 y1 z1 1
    1 0 0 0   0 1 0 0   0 0 1 0   x2 y2 z2 1
    ...
    1 0 0 0   0 1 0 0   0 0 1 0   xn yn zn 1

where (x1,y1,z1), ..., (xn,yn,zn) are the coordinates of your points,
and "point.oogl" is an oogl file containing the object you want
displayed at each of these points.  For example, you might use

    VECT
    2 4 0
    2 2
    0 0
    -.1 -.1  0
     .1  .1  0
    -.1  .1  0
     .1 -.1  0

to represent an "x".  You'll have to play around with scaling
to get the size right for your particular set of points.

You can include the point object in the INST file directly ---
betweeen the { } instead of using "< point.oogl", but putting it in a
separate file makes it easy to experiment around with different point
geometries without having to edit the (possibly large) file containing
the point coordinates.  It also allows you to have several files of
points which share the same point definition file.

--Mark