
This task shows you how to save a CATIA Version 5 Torus
as a CATIA Version 4 Torus. A V4 Torus
is created if there is a Torus
in the CATPart the customer wants to save as
model.
The customers, who want to use V5 Parts (with
a Torus surface) in the V4 are all
concerned, and the ones who want to transfer their V4 models to the V5 and
to transfer the created Part back to the V4 are also interested. 

To
be correctly transferred and to keep the canonicity of the torus, these
conditions (represented in the screen shot below) must be checked:

The radius of the generator circle must be higher than V4 point tolerance but lower than V4 infinite tolerance

The distance between the torus center and the
generator circle center must be higher than V4 point tolerance and lower
than V4 infinite tolerance

The distance between the center and any point
of the torus must be lower than V4 infinite tolerance

The center and any point of the torus must be
in V4 domain. Any point of the torus must have coordinates lower than V4
infinite tolerance

The radius of the generator circle must be
lower than the distance between the torus center and the generator
circle center

If there is some surface concatenation, the
canonicity may be lost. This restriction is true for all canonic
surfaces.
If
one of these conditions is not checked, the transfer will be done, but
canonicity will be lost.
