The age of computer graphics animation is upon us. Television 
programmes from Question Time to Question of Sport and Blind Date to 
Newsnight all use sophisticated animation sequences. People are 
realising the incredible potential of the computer's virtual world. I 
hope I can show that even the humble Archimedes 310 can give the IRIS 
workstations at Digital Pictures a run for their money.

It is this ability able to create anything and place it in a "real" 
world situation that is leading manufacturers to use computer graphics 
for adverts, costing many thousands of pounds.

I only use Silicon Vision's software, as I have found the FilmMaker 
package to have far superior smooth shading and compaction techniques. 
There is no doubt that the "front end" is far less "pretty" than its 
main competitor, Mogul, but for the added advantage of extra, better 
rendered frames I have always used FilmMaker, and hopefully soon, 
Solids-Render. After all, it's the final animation sequence that 
really matters, not how pretty the icons were in the main program.

Animators such as John Lasseter from Pixar USA manage to put life into 
any object. (Lamps, snowmen, uni-cycles etc). My animation is a humble 
attempt at my own lamp demonstration. PLAYFULAMP, features a perfectly 
rendered darkly lit room containing a table and waste paper bin. On 
the table is a teapot, a mug of coffee and an angle-poise lamp. Having 
toured Digital Pictures the main thing I realised is that the best 
animations have the most detail. Consequently, my lamp has a bulb of 
the correct dimensions, realistic colouring and an on-off button. The 
teapot was modelled from a real teapot.

The lamp, being playful, bends down on its back joint and knocks the mug 
into the teapot, from here the mug rebounds and eventually skids off 
the table falling in a parabola onto the edge of the bin. It then 
falls into the bin proper. If you have a 310, here's where the animation 
stops. Anything above and you can witness the mug's return. After a 
pause to catch it's breath, the mug hurls itself onto the edge of the 
bin and then leaps onto the teapot, sliding off onto it's former place 
on the table. However, due to the "loop" feature installed onto the 
disc the mug has little time before the lamp knocks it off again!

The animation takes about 7 seconds, has full lighting effects and 
runs at the standard Hollywood frame rate. It took 15 minutes to 
compute, display, compress and store the entire sequence. Design of 
all the objects, lighting, camera & object movements took me about 4 
hours in total.

What follows is a rough breakdown of how the demo was made. As with 
most computer graphic packages, the objects are "modelled" first. Then 
they are placed into a "scene". The object animation paths are drawn 
and the objects "locked" onto that path. The camera position, 
movement, focusing & direction are then set. Finally the lights are 
placed around the scene with the correct intensity.

For those of you who are used to programs being more simple than this 
and think this laborious, I suggest you consider this. SolidCAD gives 
you absolute freedom of form, and FilmMaker allows for virtually any 
type of animation, in any light source, with any camera movement or 
focusing. The problem with a "pretty" package is that in general the 
user has less interface with the software. This often means that the 
user is left, hopelessly trying to make the software do something. 


As stated above, the best way to make objects in any program is to 
break them down into their smallest parts. Silicon Vision calls these 
macros. The lamp consisted of 5 macros. The bulb is simply a "sweep" 
of a bulb shape which then had the silver colour applied to the base 
using a feature called "region". This is similar to taking the bulb 
and dipping it in a vat of silver paint! The shade was made with a 
similar sweep and the base also.

An important thing to consider when attempting to design a large 
object is to keep all the shapes with as few "facets" or sides as 
possible. Hence, with a sweep option, you do not need 360 small 
triangles to trick the eye into thinking the shape is circular. In 
fact 15 triangles were used for all circular objects, and this is 
plenty. 

The last two macros for the lamp were extrusions. This is where an 
object is built up from a flat shape that is stretched along a given 
axis. For example, a square drawn and extruded will give a cube. The 
other 5 facets of the cube are automatically made. This is how the 
small yellow base support and the four red lengths for the lamp were 
made. The beauty of a macro is that you can move it & stretch it along 
any axis. This allows you to work on a basic object and then tailor it 
for the final composite scene. For more precise objects the program 
adopts the industry standard of 1st and 3rd angle projections.

As an example, I loaded the bulb macro first and then placed the lamp 
shade around it. The other lamp-macros were scaled and placed in the 
scene. An important tip is to save everything as you go along as 
macros. This allows you to shift them round the scene, rescale them 
and rotate them at will.

The table, bin, and mug are all fairly easily constructed and so is 
the main body of the teapot. The only other parts that need some 
explanation are the teapot spout and handle. Both were constructed in 
similar ways. The spout started off as a cone made by a sweep. This 
was rotated (as a macro) and positioned on the teapot body. Then 
another feature of "region" was used. 

A section of the spout was enclosed in a region-box and then "pulled". 
This is where the lack of pretty icons really doesn't matter. The 
program effectively allows you to manipulate an object as though it 
were putty. You can move any section of an object. The program 
automatically stretches the adjacent parts of the object up to the 
newly positioned section. Hence the spout was modelled into a curve. 
The handle started as a "half-polo" which had its middle section 
stretched.

Having made all the objects and saved them as macros you now have the 
pleasure of being a director. Lean back in your chair and shift the 
objects around your scene. Go to a real angle-poise lamp and measure 
it. Make sure the size of the mug is in proportion. In my scene I 
rotated the teapot and lowered the table.

It is at this stage you can either save the whole scene, or, put the 
lights on and check where they should be positioned. As in most 
object-design programs the objects are shown in three views. Front, 
side and plan. Also included is a projection, which translates the 2-D 
data into a 3-D picture. This is shown in selected "style". This can 
be any one of many. There is simple wire frame, a surface
representation, many facet representations, and, the style I used, two
types of smooth shading.

Now the scene is ready to be animated. This is using the next program, 
FilmMaker. Basically this now allows you to animate the objects and 
move the camera. This is done using any number of 26 "paths" labelled 
"a" to "z". A path is drawn as a number of "nodes" which shows the 
exact movement an object (or region of an object) will move along.

To make a ball bounce down some stairs I would draw the path and 
region the entire ball (put it in a "bounding-box"). The ball will 
happily bounce down the stairs, as it is assigned to the path. But in 
my demo, I only wanted to move one part of an object and have it pivot 
on the rest. The lamp had to lower, by pivoting on the back hinge. 
Hence, I regioned the shade and the beginning of the supports and 
assigned them to an arc path. Therefore, the lamp shade describes an 
arc, nodding by pivoting on the back hinges, like a real angle-poise. 
However, I must stress that regioning can just as easily be used to 
move an entire object.

My most recent demo relies heavily on this regioning. It is a smooth 
shaded face, which is able to smile. I have simply regioned the 
corners of the mouth and make them move along an arc outwards. By the 
time I have finished I hope to be able to wiggle the ears, close the 
eyelids, flare the nostrils and even pout the lips! This face has been 
far harder to model as I have had to construct it facet by facet!

Finally to complete your animation you make a path for the camera to 
follow and/or a path for it to look at. My demo uses a moving camera, 
that always looks at the mug, hence the mug is always in the centre of 
the screen. I find that experimentation can get the desired results 
quicker than closing your eyes and pretending to be a camera!

The animation is now finished. Fine tuning using a "step" feature 
which allows you to move one frame at a time through the animation is 
useful. You can adjust paths by a fraction and then step backwards and 
forwards over the same frame to check it looks correct.

The whole sequence is then saved as compressed delta-data files on 
disc. This allows about 4.5 seconds of a fast-moving, smooth-shaded 
animation on a 310 and about 20 seconds not using smooth shading. 

A 440 machine with an ARM 3 and hard-disc will allow many more times 
the figures I have quoted, but that doesn't mean you should be 
discouraged if, like me, you only have a lowly 310. There's plenty 
that can be done in 20 seconds!
