Animating a Solid 3D Object #3

    This is one of the most advanced
and accurate methods of producing
Animation sequences possible on an
Atari ST. It is useful when you have an
object which you wish to animate at
different angles ie. rotate it around
an axis, or more than one axis. This
tutorial will be a little different
from the others in that it doesn't
involve you actually doing any work to
create the effect.
    A number of files will be used to
demonstrate exactly what procedure you
should use. Load them all in now:
"TUTORIAL.CPT" picture file (load into
screen 0), "EXAMPLE.3D" and
"TUTORIAL.SEQ".
    The first thing to look at is the
3D object which had to be created
before anything else could be done:
Enter the 3D Construction Studio by
clicking on the 3D Obj button on the
Main Menu. Select the 6th object by
using the selector towards the bottom
right of the screen (with the numbers 1
to 8 on it). You will see a very basic
sort of aircraft shape on the edit
windows. The great thing about this
method is that the 3D object, which is
by far the most difficult part of the
whole procedure, does not need to be
very accurate and detailed.
    Now go onto the 3D Viewing screen
and spin the object around to see the
sort of views you can create. Get back
to the Main Menu now and enter the work
screen. You will see that each image
has been spaced out equally. Each image
was rotated at 20 degree intervals
(Bearing) from the next on the Viewing
Studio, then plotted onto the work
screen. Equal spacing was achieved by
placing a grid (using the Grid mode) of
rectangles on the work screen to start
off with, of about the size of an image.
    Looking at the work screen, you will
see that the wire-frame lines and the
grid line have been wiped off and each
image filled in using the Zoom mode. Go
into Zoom mode and have a quick look at
some of the images.
    Now go into the Animation Studio
and press the Animate 'All' button.
This is the complete sequence. The
whole procedure isn't actually very
complicated, but it often takes quite
some time to create more complex 3D
objects and fill in all the images
with Zoom mode.
    If you want a bit of a challange,
then try making a solid animation
using the 5th 3D object. This is a car
which is made up of 100 lines! You
could even spread the animation over
three or four screens!