Lots to answer, let's go! Hope I don't repeat what was answered already. Starting by the .wad and its files...
.ccl - This is a GP4Builder exclusive format, not read by the game, so no need to store it in the .wad. Used to import/export cc-lines.
.cfp - This one stores the crowd flashes positions. I tried editing a .cfp file once but couldn't see any change ingame. I believe flashes have no relation to CROWD_ objects, that is, you can delete these objects and still have flashes, but it's been a long time since I tested this so I might be wrong.
.env - Specifies which corresponding textures (env*.tga) are used by static reflections in specific track sectors. From what I can see, there is one default reflection (usually envface*.tga) and this file specifies the sector ranges where an alternate reflection map is used instead. Not used if dynamic reflection is enabled.
.hze - Properties of the heat haze effect, when enabled ingame. It's in plain text, I believe its format to be three coordinates for position (X, Z, Y - see below), three for size, and two for orientation. Never run tests on it so I can't guarantee.
.vcl - No idea.
weather.wdt - Skydome properties and general track lighting parameters, some nice investigation on it has been done here:
https://www.grandprixgames.org/read.php?4,1044268. One thing to note is it affects only the game-generated skydome; if the track has a 3d skydome (which many custom tracks do), its properties are determined in the .gp4 file as any other 3d object.
resources\tarmacmap.tex - Used only if "bump mapping" is disabled in graphics options. This could be any texture (you could make a Mario Kart Rainbow Road with it), but tarmac color always reverts to gray if bump mapping is enabled. I don't know why there is a second texture for this, not all tracks have the second one.
resources\trackmaps - This folder contains the images used by the ingame map if "Arcade overlays" are enabled.
samples\reverbdata - This folder contains the reverb.bin file, which controls the noise reverb effect (most noticeable at Monaco tunnel). GP4 has four reverb "modes": no reverb, reverb above (bridges), reverb on sides (used in Monaco where many buildings are close to the track, and also Spa where there is tall terrain next to the track), reverb above and on sides (tunnels). This can be edited with an hex editor, I'll try and remember to describe its format when I have time.
samples\crowddata - This folder contains the .crd file, which control the sources (position and intensity) of crowd noise. Some years ago me and Lo2k realized these had the same positions as CROWD_*_FULL objects in the .gp4, so GP4Builder has the ability to generate a .crd.
Now for general questions... the flashes issue I told all I know above, so let's go to the others.
Red lights animation - All you can do with it is change its position in the [StartingLights] of the .ini file.
Darker tarmac on tunnel - Reversing the normals on the .bin is one option (I don't like the idea of
reverse normals, but it works), using a SHADOW class object slightly above track also works (but the effect might not be as good). I don't remember how it's done at the original Monaco track, better answers might be in those files.
Bumps - Can be controlled by the last few parameters of magic data (by the way, the topic on magic data discussion is my absolute favorite
https://www.grandprixgames.org/read.php?4,1012878). Alternatively, you can use GP4Builder's Track Profiler to add some randomness to track banking and create bumps as a result.
Animations - Restricted to atx_flag textures as far as I know. File names and number of frames are all fixed and can't be changed.
(X, Z, Y)? - Yes, most coordinates in GP4 are stored in "screen coordinates" while GP4Builder uses "world coordinates" so Z and Y are swapped. I guess one of them is also reversed but can't remember exactly.
I'm not at home so some things I wrote from what I could remember, also thanks for kerley for providing me a .wad to look at and refresh my memory.
General piece of advice, in doubt always look at original, unmodded files; based on the assumption that the game creators knew how the game works, and we modders don't (fully).
My unfinished tracks: [
www.grandprixgames.org]
Send bug reports and track editing questions to
f1virtualblog@gmail.com