U3D v.1.0 Unreal model conversion tool file

U3D v.1.0 Unreal model conversion tool.
(c) 2000 Thomas B. Beard

Yet another Unreal model converter...

Presently there are at least four other unreal model
converters out there but as you may know, each one has it's
own set of limitations that either make the conversion
process a pain in the rear, or plug in to a specific
version of 3D StudioMAX.

This release of U3D only supports conversion from
3DStudioMAX .3DS files and I have only tested it on .3DS
files generated by version 3 so you may run into problems
with older or converted .3DS formats. I may add other 3D
input formats in the future such as .DXF and .ASC assuming
they can supply all required mesh and texture data. This is
the first release of the U3D conversion tool, so if you
spot a bug or find a way to consistently crash it :) just
send me an e-mail, my address is listed below.

-- U3D Options --------------------------------------------

Input Field
Type in the name of the source .3DS file or click on the
'...' button for a file selection dialog.

Output Field
Type in the name of the output .3D file or click on the
'...' button for a file selection dialog. If you are
overwriting or appending animations to an existing file,
you can select either the <name>_a.3D or <name>_d.3D
file.

Vertex Conversion
Unreal .3D model format requires all vertex points in
your mesh to be located inside of the (-128 to 128)
range. When converting the mesh, you will lose a little
precision as the vertex points are snapped to fit a
.3D model grid. This is why it's a good idea to make
your models fit as closely as possible to the (-128 to
128) boundaries. To simplify your work, U3D will
automatically correct points outside of the (-280
to 128) range by one of these methods:

- Uniform Scale
If your model(s) have any points outside of the (-128 to
128) bounding cube, they will automatically be scaled on
all axis to fit and the uniform scale value will be
displayed in the status log. If all of the models points
reside inside of the (-128 to 128) range, a uniform scale
will not be applied. The same uniform scale will be
applied to all models imported.

- X,Y,Z Scale
Similar to the uniform scale, however each axis may be
scaled differently depending on how far points extend
past the (-128 to 128) bounding planes on each axis.

- Clip Bounds
Any points that extend past the (-128 to 128) range will
be capped. This may distort your model quite severely but
it is useful for hand animations where the maximum range
may not be visible.

Animation

- Append Frames
Checking this box will append all converted frames to the
end of the selected output file. This may cause problems
if you rely on U3D to scale any out of bounds meshes
because U3D will not remember what scale factors were
applied to the previously converted frames. You can
avoid this problem by ensuring your model and all frames
do not extend past the (-128 to 128) limit.

- Convert by object name
When this option is selected, every mesh object in the
.3DS file will become a separate animation frame, and
will be converted from it's first keyframe position. All
other keyframes will be ignored. You should choose a
different name for each object, numbering them is
probably the easiest to manage. While converting, the
sorting order of the names will determine the animation
sequence.

- Convert by key frame
This option is by far the easiest way to convert an
animation sequence because it will use the animation as
it appears in the 3DS file (by keyframe). You may have
multiple mesh objects in the scene and they will be
combined to form the final .3D mesh. Please note that
converting by keyframe does impose limitations as
described below.

Alternative command line interface

Useage:

U3D <Input file> <output file> [-append -xyx -clip -byname]

-append is the same as the 'Append Fames' option
-xyz is the same as the 'X,Y,Z Scale' option
-clip is the same as the 'Clip Bounds' option
-byname is the same as the 'Convert by object name' option

By default U3D will use the 'Convert by key frame' and
'Uniform Scale' options.

-- Before you begin... ------------------------------------

Please be aware of the limitations placed upon .3DS files
and their conversion to the Unreal .3D format.

1 - When using 'Convert by keyframe', each mesh object must
exist in every animation frame and can not be modified
between animation frames at a sub object level (Points,
Edges, Faces, UVW Mappings), you can only change the
entire objects translation, rotation and scale. This is a
limitation of the .3DS file format as of 3DStudio MAX R3.
If you need to make changes to the sub object geometry,
you must use the 'Convert by object name' option which
takes a bit more work to prepare. MAKE SURE you are on
the first keyframe (frame 0) before you export, or the
converted animation sequence will be hosed :) .
There also seems to be a bug in 3DMax where it will drop
the final keyframe scale information, so you may need to
manually fix your .3DS file. As you may have guessed,
pulling keyframes from a .3DS file is HIGHLY experimental
at the moment so you may run into situations where U3D
does not produce the expected results. First try filling
in any keyframe gaps (translation, rotation and scale)
and as a last resort you can use the
'Convert by object name' option which is quite a bit more
reliable but a lot less fun to use.

2 - The total number of points and faces in each
animation frame must be the same. This applies to both
'convert by keyframe' and 'Convert by object name'.

3 - When using the 'Convert by object name' option, you
may only have a single object mesh per animation frame.
If you have two object meshes with the same name, they
will still be converted as separate frames but may not
be placed in the correct order so numbering them is
usually a good idea. Keep your object names no greater
than 10 characters in length (another .3DS limitation).

4 - Only UVW texture mapping is supported. See the UVW
walkthrough below. Unfortunately .3DS files save UV
mappings by vertex, not face so if you place multiple
UV mappings to a mesh you will run into problems any
place two textures connect. You can fix this by splitting
apart you model by texture in effect duplicating all
previously shared points or you could design a texture
that seamlessly wraps around your model which takes a
bit more planning.

6 - Lights cameras and other goodies will be ignored when
converting.

-- Special names ------------------------------------------

U3D supports special object and material names that will
translate into Unreals .3D functionality.

!<objectname> - Any mesh Object with a name beginning with
an '!' will be ignored.

skin# - Denotes a skin texture that will be used in the UVW
mapping conversion. '#' denotes a number from 1 to 9 You
may have up to 9 skins, but try to use as few as
possible. The number you choose here will be the same
number you give the .UC #exec command used to import the
texture into unreal. Ex:
#exec MESHMAP SETTEXTURE MESHMAP=SRifle NUM=1 TEXTURE=SRiflea

<materialname>*W* - A triangle with this material
mapped to it will become the weapon triangle used to
align player and weapon models. You should only have
one weapon triangle for a character model.

<materialname>*M* - Polygons mapped with this material
will become mask polygons.

<materialname>*O* - Polygons mapped with this material will
become modulated polygons.

<materialname>*F* - Polygons mapped with this material
will become flat polygons.

<materialname>*T* - Polygons mapped with this material will
become translucent polygons. You can adjust their alpha
values in Unreal.

<materialname>*2* - Polygons mapped with this material will
be flagged as two sided.

<materialname>*E* - Polygons mapped with this material will
be environmentally mapped.

<materialname>*N* - Polygons mapped with this material will
use the nofilter setting.

<materialname>*C##* - You can adjust the color value of
polygons where ## denotes two hex numbers 00-FF.

<materialname>*X##* - You can set the extended polygon flags
where ## denotes two hex numbers 00-FF. I am not sure
if these are actually used by unreal but they may be in
the future.

Any of the trailing letter materialname formats may be
combined for multiple effects. You may also use two or more
materials that start with the same 'skin#' which will allow
you to place different effects on polygons mapped to the
same texture.
Here are a few examples of valid material names:
'skin1 TC04'
'skin1N2'
'skin2 X56E'

-- Textures -----------------------------------------------
I generally use large true color image textures while
modeling, Photoshop layered images are invaluable here.
The models textures usually take more revisions than
the model itself so a high end image editor is best.
Keep in mind that you will eventually be scaling your
texture down to a 256x256 pixel, 8 bits per pixel
(256 color) .PCX file. You may need to make use of
multiple textures to achieve a wide amount of color
variation.

-- Texturing using 3D Studio MAX R3 -----------------------

U3D currently only supports UVW mapping of textures. UVW
mapping is highly flexible, allowing you to place different
portions of a bitmap texture on specific faces of a mesh.
You can cut down on the number of textures used by dividing
your bitmap up and applying it to multiple locations.

Here are some quick 3DStudioMAX R3 step by step
instructions to get you started.

1 - Import your bitmap. Open the Material editor (the icon
with the 4 spheres). Select the first material
(upper left) and make sure it's type is set to
'standard'. Now scroll down and open up the 'Maps'
rollout. Check the 'Diffuse Color' box and click on the
button to it's right. Select 'Bitmap' from the list that
pops up (Make sure the 'New' radio button on the left
is selected). Click on 'Ok' and you will be prompted to
select an image to use. You should now see the image
applied to the first material and the 'Coordinates'
rollout should be opened below. Make sure 'Texture'
is selected and 'Explicit Map Channel' is selected
in the dropdown. All other parameters should be left
to their default values. While you are here make sure
to select the blue and white checkered box in the
horizontal toolbar. This will force 3DMax to display
the texture when you apply it.

2 - Rename the material. To get back to the top level
material properties, you must click on the up arrow
(sort of a return arrow pointing up located between the
materials and the 'coordinates' rollout). Change the name
in the text field to 'skin0'.

3 - Apply the texture. You can either apply the texture to
an entire mesh or to just a few selected faces, simply
drag the material from the material edit window and
drop it on to the mesh.

4 - Align the texture. Click on the modify tab (should be
the second tab over on the right panel of the
application). Press the 'UVW Map' button and the
'Parameters' rollout will open. Play around with the
settings here until you get the texture lined up
properly. If this is your first time UVW mapping, spend
some extra time exploring the parameters here.

5 - Collapse the UVW mapping. In the 'Modifier Stack'
rollout, just above the 'Parameters' rollout, you will
need to click on the little box toolbar button to open
the 'Edit Modifier Stack' Dialog. Click on the
'Collapse All' button and choose yes. Now your texture
mapping will stick and your model should be ready to
convert.

For more info or help with model conversion, check out the
Unreal fan sites and message boards. PlanetUnreal.com has
quit a few top notch hosted sites with tons of information.

Thomas B. Beard (Macabre)
Email: tbeard@carolina.rr.com
Homepage: Home.carolina.rr.com