rec.autos.simulators

  I got a little further today with my first 3-D file loader.  Figured I'd post
this here so others could copy it and ask similar questions too :-)  I'm
opening up a DOF file in binary as you said to do, reading in 4 bytes at a time
and am finding lots of the GOB1's, VERT's, etc., as shown on your site,
scattered throughout the file.  I'd like to try and get a nothing but a list of
triangle vertices loaded for starters.  Strange thing though, when doing this
with the Ferrari file, I find on only 33 GOB1's, with 33 VERT's.  These
indicate the beginning of a list of vertices, right?

  If so, when I hit the first GOB1 and VERT, I check the next 4-byte chunk
(after VERT), reading it in as a long integer.  This gives the number of
vertices coming up.  Then, if I start reading in data as floats, I'm getting
one vertex at a time from there on out (until some other GOB1 or something
similar is hit), right?

  Problem is, I'm seeing numbers that range from 1*10^-33 to 1*10^+23 at first
glance.  I'll try loading them as different data types.  What approximate range
of values should I be seeing here?

  Thanks,

Todd Wasson
---
Performance Simulations
Drag Racing and Top Speed Prediction
Software
http://www.racesimcentral.net/

(1)  3.363116E-44  (Wrong probably, why?  Wrong address?),  -.436,  .186

(2)  .985,-.435,.176

(3)  1.123, .429, .186

  Is this right?

  Thanks,

Todd Wasson
---
Performance Simulations
Drag Racing and Top Speed Prediction
Software
http://PerformanceSimulations.Com

  Thanks,
Todd Wasson
---
Performance Simulations
Drag Racing and Top Speed Prediction
Software
http://PerformanceSimulations.Com

Ah, gee, I went to Ireland and have been busy on the Racer forum, so
it's just now that I saw this. :)

Yes, vertex information:

VERT; vertices (triangle data only)
int vertices;
float vertex[vertices*3];

BUT make sure that the first 'int32' you read after VERT is the length
of the VERT chunk. So it will be sizeof(int)+vertices*3*sizeof(float).
This is because you might not handle the VERT chunk, and want to skip
it; you can just skip 'chunkLen' bytes.

As above, this is probably the chunk length, and only the NEXT
(4-byte) integer gives you the number of vertices.
Note that the number of actually DRAWN vertices is given by the INDI
chunks; since OpenGL can handle indexed vertices (which has some
advantages with caching and geometry/lighting), these are used to
point into the vertex array and pick out the correct vertex/normal
pairs.

You read nVertices*{ float vertex[3] } yes. Don't check for chunk you
know about, just read the exact number of vertices.

The float should probably not exceed 10 or so; Racer uses 1.0f = 1
meter.

Hope this helps,

Ruud van Gaal, GPL Rank +53.25
Pencil art    : http://www.marketgraph.nl/gallery/
Free car sim  : http://www.marketgraph.nl/gallery/racer/

First might probably be the nVertices integer that you needed. So
you're probably using the chunk length as the vertex count (the chunk
length is probably about 12x that of the vertex count).

That would also explain finding 5900 or so vertices; it's more like
1590 (try Modelers' information button, it gives the #poly's).

Ruud van Gaal, GPL Rank +53.25
Pencil art    : http://www.marketgraph.nl/gallery/
Free car sim  : http://www.marketgraph.nl/gallery/racer/

You went to Ireland and didnt come to visit!! I am offended! :)

Ash - see if I care <g>

| Ah, gee, I went to Ireland and have been busy on the Racer forum, so
| it's just now that I saw this. :)
|

Ruud van Gaal, GPL Rank +53.25
Pencil art    : http://www.marketgraph.nl/gallery/
Free car sim  : http://www.marketgraph.nl/gallery/racer/

If you are ever coming up North anywhere, you have a place to stay!

All the best,
Ash

| On Thu, 19 Jul 2001 12:06:49 +0100, "Ashley McConnell"
|
| >Ruud!!
| >
| >You went to Ireland and didnt come to visit!! I am offended! :)
|
| Ah, ofcourse the Mc should have given your location away. :) Sorry,
| Ash! ;-)
| I was in Spiddal, near Galway, but it was quite a hop in, lots of
| work, a Guinness (too bitter for me, so I switched to Smithwicks and
| whiskey), and hop out.
|
|
| Ruud van Gaal, GPL Rank +53.25
| Pencil art    : http://www.marketgraph.nl/gallery/
| Free car sim  : http://www.marketgraph.nl/gallery/racer/