SI Tools Tutorial - Adding Subobjects to Props

by: Dean Newbury


To see some examples of props with subobjects, go and download the Stunt
Island airplane props from the SITP. All of this information came from
using those props as a guide. To view the subobjects once the prop is
loaded, simply enter FILLED and hit SHOWSUB. Before we begin with the
how-to's, you have to know that SIT does not like subobjects. We've all
dealt with SI's polygon sorting deficiencies while filming movies. Well
when you add a subobject to a prop it is rare to not have sorting issues,
oftentimes HUGE sorting issues. Just for fun enter SIT and delete a
subobject from the Spitfire and then replace it exactly the same way it
was and you'll see what I mean. These sorting issues lead me to believe
that another, better prop editor was used to add subs to SI props or
ded onto existing props outside of SIT. That said, it is still very
possible to add subs to your props with excellent results! Let me list
some methods I've had to use to get subs to work:

1. Always, always, always click TRYHRD before you try adding subs!
2. After you've attached a sub, if the prop is completely unsortable
   unclick TRYHRD and click NOSORT then use FRONT and BACK in the FILLED
   menu to re-sort your prop.(Used on my TIE-Fighter prop set)
3. When you attach prop B to prop A and it doesn't work, then reverse it.
   Attach prop A to prop B.(Used on a varity of prop sets including the
   TIE and Falcon)
4. Make your subobjects a separate prop. "Build" just the attachment points
   for the subs with no polygons and then attach your subs. Then make
   this a separate prop altogether and attach it to your larger prop
   within the game itself. (Used on the X-Wing) These are just some
   examples, but you'll have to experiment because SIT sorts every
   prop differentely and you never know what will or will not work.
There are three types of subobjects : non-animated objects, animated
propellors, and animated landing gear. All subs are attached to a point,
or coordinate, within another prop from the PT/LN screen. Think of the
point as if it were a ball joint and your sub will attach to, spin
around, or fold 90 degrees on. So the first thing you need to do is
provide this "ball joint" for your prop to attach to. Then click on
the point and then click SUBOBJ and a menu will pop up. The next three
sections will discuss what goes in the blank fields of this menu.

Subobject Menu

| OBJECT | A |-| ROTATE | B | C | | COND | D | E | F |-| ELSE | G |
 A - Subobject Filename. B - Axis sub will rotate around, X-Axis, Y-Axis, or Z-Axis. C - Determines the type of
subobject your sub will be and what direction it will rotate.
D - Condition of visibility throughout animation and sets up prop
swapping for propellor. E - Controls visibility through various stages of
animation. F - Sets a rotation point where landing gear will disappear
or when a propellor will prop swap. G - New propellor prop to be swapped
with initial prop.

Non-animated subobjects

The best example of non-animated subs I have can be found on the
747 with space shuttle found within SI. All of the engines and even the
large shuttle are subobjects. I cannot begin to understand how SIT
can handle all of that extra data, but there it is. So for a
non-animated subobject your pop-up menu will look like this :
| OBJEC
T |(filename)| | ROTATE | NONE | 0 | | COND | NONE | 0 | 0 | | ELSE | |

Animated Propellors

A propellor can be attached on any axis and always spins in the same
direction on each axis. The propellor is the only type of sub that can
take advantage of what I call "prop swapping." What that means is
that at a certain point in your propellor animation a new prop will
take the place of the initial propellor. SI uses this to give the
appearance of the propellor becoming see-thru as it spins faster.
So when your propellor reaches a certain speed and rotation SI "swaps"
your propellor for another, less solid one creating that flicker effect.
The propellor pop-up menu will look like this :
| OBJECT |(filename)|
| ROTATE | (axis?) | 10 |
| COND |