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N2+ Car File Format
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Author:  Traveller [ Fri Nov 17, 2017 2:11 pm ]
Post subject:  N2+ Car File Format

If any old timers are still around... I'm looking to unravel a chrome illusion car from the N2 or so time period. Does anyone have the file format definition somewhere? Or better yet a program to unwrap the mip-maps. I thought I had the format, but the ones I have are for GPL both tracks and cars, and N4 tracks and 3DO's-- i.e. no textures.

In the meantime, I'm going to do some programming/scripting to try to decipher them.

Some information: the pertinent section headers are, "XETC","PAMB", "DHMB", and "ATAD".

I found WinMIP. It only displays the top level mip-map.

Author:  Seb29 [ Sun Nov 19, 2017 1:46 pm ]
Post subject:  Re: N2+ Car File Format

Thetrackshoppe hosts n2def and n3def programs. N3def has text of the structure info of the era papy files included. Hope this helps.

Author:  Traveller [ Tue Nov 21, 2017 4:51 pm ]
Post subject:  Re: N2+ Car File Format

Unfortunately not. I took a look at the help files, and no information was provided concerning the texture aspect of the objects. Geometry, yes. Textures, no. Thank you, though.

Author:  lordpantsington [ Thu Nov 23, 2017 6:30 pm ]
Post subject:  Re: N2+ Car File Format

I fell down a hole and after I woke from my turkey induced coma found this:!searc ... ytCDNXog4J


N2K2 has an own texture file format. These mip files contain all mip levels and
can be (5/6/5), (5/5/5/A), (4/4/4/4), (8/8/8), (8/8/8/8), DXT1 or DXT2. Usually
they are in DXT1 format.

WinMip creates these files out of a bmp and when necessary an additional alpha
map. When doing the conversion algorithm for DXT1, I ran into a problem with
multitextured surfaces not being displayed correctly. While trying to find out
what was wrong, I stumbled over a MS tool, which actually does this conversion
by loading the bitmaps into a D3D-DXT1 surface. Fine, that saves me a lot of
time. For the texture compressed mips, WinMip only does the headers.

It looks like the DirectX includes under certain circumstances the invisible
color(s) into the calculation for the resulting color in the lower mip levels.
I was told, this would be a desired effect. The artist has the possibility to
decide by choosing the invisible color how the texture blends into the
background when seen from far away.

Now, the magenta (pink) color, which Tom chose, is for sure not the best
choice. I guess, he was not aware of this effect and like me, he never saw the
low mip levels used by N2K2.

For I have no influence on the conversion process - the DX Texture tool is kind
of a black box - all I can do with WinMip is to change the texture before it is
handed over to the compression tool. Will mean I built in an algorithm which
optimizes the colors of the invisible pixels so there are most likely no color
changes at the lower mip levels, no matter which invisible color has been
chosen by the texture creator.

I have not heard of Tom yet, but the results of my test look very promising. He
will not have to redo his textures. There´s only a WinMip batch conversion
mip->bmp and then back bmp->mip necessary and the "purplization" is gone.

Klaus Hörbrand
WinMip file conversion tool

Granted N2002 =/= 2 but stepping back through each game revision might give better understanding.

Author:  Traveller [ Fri Nov 24, 2017 1:04 pm ]
Post subject:  Re: N2+ Car File Format

DXT1 may be all I need to know. I'll post results here. Thanks, LP.

Author:  Traveller [ Fri Dec 01, 2017 7:41 pm ]
Post subject:  Re: N2+ Car File Format

There's more than one way to get what you want. The .CAR file's texture is encoded somehow. So, I just used a hex editor to remove the highest car level, then used WinMIP to view the updated CAR file. Repeat for a few MIP levels to see the colors used for the chrome illusion effect.

Sample Colors
160 49 53
168 72 40
184 100 24
216 140 8

Author:  lordpantsington [ Sun Dec 03, 2017 4:25 pm ]
Post subject:  Re: N2+ Car File Format

So they used MIP level solid colors to do the blending/falloff?

Author:  Traveller [ Sun Dec 03, 2017 9:27 pm ]
Post subject:  Re: N2+ Car File Format

Yes. My method to build it is to make four different color schemes for a car. Create DXT5 DDS's of each. Then load the lot of them into a program and pick out different MIP levels from each of the four schemes to build the final one. I just wanted to see color schemes used by others for the Gordon car. Though I can't find the original scheme created by White Falcon, I think it was. I may have it on a CD or DVD of old computer files I have here in the house.

EDIT: I found the original Gordon car on a DVD I had... Here it is "unwrapped".

24_Gordon_Chroma.jpg [ 346.31 KiB | Viewed 31 times ]

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