TIPS FROM A FORMER USAF 3D MODELER

Okay, just to clarify things, I just popped in for a few days because a friend asked me some questions about how the models were built and I thought maybe you still had some questions.

Q -McFly - Thanks for stopping by. First. Is it possible to use more than 2 .bmp files for the texture mapping of the models in USAF?

A - Deus_ex - You can have as many texture files as you like; We used two because we wanted the game to run properly on older systems and that was in 99 - today, with a new machine, you can do whatever you want. You can also use TGA files with an alpha channel for transparency instead of using Cyan for key-color transparency (which never worked that well).

The way we made the texture files was like this: We took a model and simply broke it apart into parts we could map separately. Then we drew, inside 3dsmax, two spline rectangles. we arranged all the parts inside those rectangles in a tight fit, sometimes scaling up important parts. Then we rendered each rectangle with the parts inside and we had a template to paint the texture on. To paint it we used a number of sources - we scanned plastic models, drawings in books, and we had a professional artist who drew 3 images of each aircraft - from top, side and bottom. We then cut and pasted parts of those images into the Templates. Then came the hardest part, going back to 3dsmax to the model after we broke it apart but before they were rearranged in the rectangles, and then we manually applied UV coordinates to each part.

It was a lot of hard work but later I came up with a method that saved me a lot of work, and which I still use now. It's quite easy and has better results than chillyskinner.

What I do is this: I still break a model apart manually, but before I arrange the parts in a rectangle to create the texture, I first make an instanced clone of everything and arrange the instances. If some part, say the engines of a 747, receive the same texture, I first make instances of them on the model so later they all get the same coordinates.
Now I arrange the instanced parts in a rectangle. they are still linked to the original parts of the model, so what I apply to them will be passed on to their instances.
Still, I can scale them if I want.
I render the rectangle as usual and create a texture. I can already apply it to the model.
Now I select the spline rectangle, apply a UVWmap modifier, make sure it fits exactly (by default 3dsm adds another 0.1% size to the texture when it auto-fits it). I select all the instanced parts inside the rectangle, apply all of them another UVWmap modifier, choose "aquire" and aquire the coordinates from the rectangle. Automatically, all the instanced parts in the model receive their their correct UV coordinates. Job done.

Q -McFly - Do you know how to open the .pal files that are associated with the explosions and afterburner flame

A - Deus_ex - Now, about those Pal files: I remember having a hard time with them. I loaded them as RAW files into photoshop. For those who don't know what that is, these are files without definitions of channels, pallette, or size - you sort of have to give Photoshop the details for it to load the file successfuly.

The 2 large files are vertical strips with a series of images that create an animation. both have 2 8-bit channels: one grayscale (or maybe plaletted?) color channel and one alpha channel. The header is 8 bits long. The one with smoke has a width of 64 and the one with an explosion is 128 pixels wide.
I don't remember the height but it's simple math - the size in bites of the file, minus 8 bits of header, divided by # of channels (2), divided by # of bits per pixel in each channel (8), divided by width - 64 or 128.

The other files, some have 2 channels and some have 4 - RGB + alpha. You'll have to guess the sizes, but mostly they're powers of two - 32x32, 64x64, and such.

I don't know what you're going to do with the info though, all the effects in USAF were hard coded and I didn't know more can be added.

Q -McFly - Do you have any tips on the terrain mapping?

A - Deus_ex - As for terrain - that's a complicated issue. The ppl who worked on terrains used some custom software to compress the terrain image. I'm not sure how it worked But I remember there were a number of layers one on top of another, so maybe they somehow used PSD files? just a guess. Probably a wrong one.
The DEM files I think are a standard in GIS applications. Don't know much about them. I onece managed to open one as a 2-channel RAW file.

McFly - Thank you kindly for sharing this oh so hard to find information.

CONVERSTATION WITH YET ANOTHER
EX-PIXEL GUY CONCERNING TERRAIN AND OTHER MYSTERIES WITH ARIEL CANCIO

(Ariel Cancio)_ Dear Xmen,

(Xmen)_ <Hi Ariel>

(Ariel Cancio)_ I am writting to you because you are the only
person who can help me. I am a flight simulation's fan, especially USAF's admirer, which you were involved when you worked for pixel company. I have created new model's planes with other accesories to insert in the USAF. It is a personal and free proyect, which is connected with the Fackland Island's conflict originated in 1982
.

(Xmen)_ <nice>

(Ariel Cancio)_ The main problem appeared when I tried
to insert a new scenery, which is absolutely different from the other stages that USAF actually has. The reason, is as you know, that only the USAF creators know the software they used to compress the satelital images. Therefore, I would be grateful if you could send me some information about: *Which software compress images in format file.DEM?

(Xmen)_ <Pixel proprietary tool, we take a 16Bit color mapping of the elevation. in USAF it was in 10M per pixel res ( height) today similar technology is used on real FS and real debriefing stations that are built by SIMIGON INC. and goes to much higher resolutions.>

(Ariel Cancio)_ How do you make the surface reliev?

(Xmen)_ < The render system decompress the layers of image , DEM , and MAP using a jpeg based compression and a special streamer that loads the right layers from the disk.
then the real world 3D triangular points are computed , textured and rendered>

(Ariel Cancio)_ What information has the format files.Map and files.Ptt?

(Xmen)_ <Pixel format : Pixel terrain type its a multy resolution jpeg based compression>

(Ariel Cancio)_ Will be posible to add a new stage or will I have to replace one of them?

(Xmen)_ <I you can change the files somewhere in the admin.ini file>

(Ariel Cancio)_ Do you know how to include new airports? The only thing we have achieved if to include the shape of the runway, but it isn´t landable. How can we include new landable runways in the maps?

(Xmen)_ <. I think Airport where a special terrain type defined in the terrain db using a visual tool. just like water land rocks etc. I do not know where can you get this tool>

(Ariel Cancio)_ Is it possible to include more 2D and 3D cockpits? So far we succeded in including some new cockpits, but the number is limited to 12 if I´m right. How can we include more cockpits?.

(Xmen)_ < I think the planes types are unfortunately hard coded, sorry Ariel.