Often when constructing a
viewpoint for a VRML scene, one would like the viewer to look
towards some particular point, for instance, the location of an
object in the scene.

This means that most often one knows the
coordinates of a point one wishes the viewer to be able to see,
and the point that you wish to view it from.

To make a VRML viewpoint, you then
need to find a rotation to apply to rotate from the standard view
which looks at the origin from the negative z axis.

To do this, you need to find a
suitable axis, and angle of rotation. This
involves use of some maths .
Even if you know how to do it, it involves multiplying together
matrices, and solving simultaneous equations, which takes a while
to do by hand. So it is a clear case where a program is
needed.

How to use

Type in the viewpoint name, and
the coordinates you wish to view from, and view to.

Adjust the tilt and field of view
if desired. The tilt value tilts the view about the line from the
viewpoint to the point viewed - like looking at it with your head
tilted to one side.

You can then copy and paste the
result from the VRML
Viewpoint box into your VRML file.

Some extra details

Changing the number of significant places to
show box changes all the numbers -
the ones you type in yourself, and the ones that make the new
viewpoint.

The choice of degrees / radians / whole turns
affects only the numbers you type in yourself -
VRML viewpoints have to be defined in radians.

You can enter formulae in any of
the fields as well. These can use brackets, also +, *, -,
/ for the four arithmetic operations, and ^, ** or | for
exponentiation.

If you need them you can also use C for cos, S
for sin, E for natural exponentiation, T for tan, P for pi, L for
natural log, and R for square root.