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<p><b><font size=+1>SoftImage Tips and Tricks</font></b>

<p><font size=-1>gregw@wdi.disney.com</font>

<br><font size=-1>updated 2/26/2002</font></center>

<p>The following document contains certain advice for getting models and

animations through the

<br>soft2egg converter in one piece.&nbsp; Some of these restraints are

due to differences between Panda

<br>and SoftImage and some are workarounds for SoftImage&nbsp; idiosyncrasies.&nbsp;

The first section is advice

<br>for set-up, modelling, and animation. The second section describes

some frequently seen problems

<br>after conversion attempts. If you have any questions please don't hesitate

to ask.

<br>&nbsp;

<br>&nbsp;

<p><b><u>Section I&nbsp; - Set-up</u></b>

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>Hierarchy naming:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The converter needs to ignore

most of the constraint hierarchies and they are not always

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; flagged invisible so the

code will ignore any nodes (and anything below them) with the

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; following strings in their

names:

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

con-

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

con_

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

fing-

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

eyes-

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

faces-

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

head-

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

camRIG

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

bars

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; If you don't do this, the

converter will make geometry for the sliders and the camera. I freely

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; admit there is some kruft

in this keyword list.

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>Model naming:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Try to make the models have

consistent names through the revision process. SoftImage is

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; terrible about appending

version numbers onto everything in the scene file (null12_1_1, etc.)

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Each time a model name changes

it's highly likely that a makefile or the show code will break.

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; While it is possible to

"fix" this with wildcards (null12*) it is undesirable as this is no longer

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; unique and can cause other

problems.

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>NURBS Textures:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Textures applied to closed

NURBS surfaces in Soft will have problems in Panda. This is because

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Soft uses phantom vertices

in their NURBS representation and this seems to affect where they

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; start and stop applying

the texture. This can be fixed by shifting the NURBS parameterization.

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; You can do this on the surface

in question through the Soft GUI, or you can do for all surfaces

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; in the scene upon conversion

with the "-x" option to soft2egg.

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>Model scale:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; It seems the general convention

here in the VR Studio has been for the animators to scale the

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; character models up by a

factor of four while animating. I believe this is because Soft has limited

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; precision. Thus models should

be scaled by a factor of one fourth to look right in Panda.

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>Non-uniform scaling of joints:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; A non-uniform scale is one

that is not the same in all three axes (ie x=1, y=1, z=0.5). If an

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; animation puts a non-uniform

scale on any joint then you must place the key word "scale-" in

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; the name of the joint that

does that scale.

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>Face shape trickiness:</u>

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Currently SAAPHIRE (the SoftImage

API) is broken when it comes to reading expressions

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; which determine shape weights.

Because of this you MUST put the expressions in strict order

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; of the shape numbers they

affect (ie the expression for shape 0 must be before 1, etc.)

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>Animating Nulls:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; When constructing a skeleton

for the player the converter looks at the skeleton nodes in Soft.

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; If you are animating a null

directly through some relationship you need to make the converter

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; aware of that by flagging

the null with the prefix "joint-" in its name.&nbsp; Alternatively, you

can

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; do a "GroupAsSkeleton" on

the null in question to make it actually part of the skeleton. It will

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; then have a tiny "Skel"

above the node in the Soft's schematic view.

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>The Minus One Frame:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Our animation system works

by computing offsets from a neutral pose in the -1 frame of the

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; scene file. If the character

is not in the "jesus pose" at frame "-1" all bets are off. Animation

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; should not start on anything

in the scene until frame "1".

<br>&nbsp;

<br>&nbsp;

<p><b><u>Section II&nbsp; - Known Pathologies</u></b>

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>Part not where it should be:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Frequently Soft does not

update the position of parts that are moved and skinned. It will look

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; right in Soft until you

cut it out of the hierarchy. If the geometry stays where it is after cutting

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; it&nbsp; is fine. If it

pops to a different position it will be problematic. We never did find

a way to make

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Soft update its position

but we did find a fix: do a "duplicate immediate" on the geometry while

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; it is in the correct position;

cut out the old geometry and delete it; skin up the new copy you just

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; made.

<br>&nbsp;

<p>&nbsp;&nbsp;&nbsp; <u>Part stretched out while animating:</u>

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; If you put a non-uniform

scale on a joint and don't tag it as described above it will most likely

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; be extremely stretched out

and creepy looking on playback (like Edward Scissorhands). There are

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; other things that can cause

this too (like scaling an egg model and not the egg anim channel and

<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; vice versa). But when in

doubt, throw in the "scale-" flag.

<br>&nbsp;