Alhexx' Capsule BAC Format Description 1.0

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This file format seems to be a quite simple one.

There's a very simple header with only 16 Bytes, with an
ID of 4 Bytes at the beginning.
After that, there's an 32Bit Integer telling you how much
Vertices there are stored in this model. Then comes the
Vertices Pool with this format:

Type		Length		Function
----------------------------------------
Integer		4 Bytes		ID of Vertex
Float		4 Bytes		X Coord
Float		4 Bytes		Y Coord
Float		4 Bytes		Z Coord

In other word, the vertices have an ID, followed by the 
XYZ Coords.

After the Vertices Pool is finished, the Group Pool starts.
First, there's an 16Bit Integer telling you the Number of
Groups. 
What follows is the Group Pool itself. Every single Group
is variable-sized! They're Build up like this:

Type		Length		Function
----------------------------------------
Integer		2 Bytes		ID ???
NullString	Variable	Specifies the Group Name
-		36 Bytes	unknown, probably Bones ?
Integer		2 Bytes		Number of Polygons
-		Variable	Polygons Data

The Polygons Data is interesting. Every Polygon is stored
as an 16Bit Integer and read out from the Polygon Pool.


And last but not least, there's the Polygon Pool at
the end. First, as always, there's a 16Bit Integer telling
you the number of entries here...
Then an array of Data follows, each entry is 26 Bytes long:

Type		Length		Function
----------------------------------------
Integer		2 Bytes		Tag (always = 0xFFFF)
Integer		2 Bytes		Vertex 1
Integer		2 Bytes		Tex-X 1
Integer		2 Bytes		Tex-Y 1
Integer		2 Bytes		Vertex 2
Integer		2 Bytes		Tex-X 2
Integer		2 Bytes		Tex-Y 2
Integer		2 Bytes		Vertex 3
Integer		2 Bytes		Tex-X 3
Integer		2 Bytes		Tex-Y 3
Integer		2 Bytes		Vertex 4
Integer		2 Bytes		Tex-X 4
Integer		2 Bytes		Tex-Y 4

The Tex-? things are the Texture Coords for that Vertex.
You should know that the Polygons aren't Triangles;
they're Quads. So, if you want to use the model in normal
modellers, you'll have to convert this Polygons into
Triangles. Here's an example:

(You should use a fixed-size font for this...)

       1           2      1           2
        +---------+        +---------+
        |         |        |\. TRI 1 |
        |         |        | '\.     |
        |  QUAD 1 |        |   '\.   |
        |         |        |     '\. |
        |         |        | TRI 2 '\|
        +---------+        +---------+
       4           3      4           3

So, if the Quad uses the Vertices 1 to 4, you can create 2
Triangles:
One with the Vertices 1, 2, 3 and one 1, 3, 4.

You see, there's a problem with the Polys. Usually, the
Tex Coords are stored in the Vertices, however, it this
case, one Vertex can have multiple Tex Coords if it is used
by several Polygons. (That's one of the main reasons whay
the MS3D JILL Capsule Importer is still beta...)
You will have to create a lot of technical procedures to
get a good solution for this problem. Of course, you can
create 4 Vertices for every single Polygon, but that would
end in a huge amount of vertices... so good luck! I'll see
if I can program a useful solution in my Importer.
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I know this was a kinda short description, but I think it
contains everything you need to build a viewer/converter.


~~ Greetings Fly Out To: ~~
Darkness
Ficedula
Kaddy #17
Kaoru S. Night
Mirex
Phaeron
Qhimm
Sephiroth 3D
ShinRa Inc.
The SaiNt
... and everyone I've forgotten!


Visit or contact me:
--------------------
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Mail  : alhexx@alhexx.com


 - Alhexx
16:37 2002-11-16