I thought I was the only person ever pathetic enough to resort to this method!
The only things I would add to MZ's good advice is:
1) Try psxprev on all versions of Tomba games (Japanese 1 and 2 etc). It's possible that one of them will use the standard formats.
2) I was never sure if the flattening of the Z coordinate in emulators was caused by the PS1 itself or if it was a speed shortcut imposed by the emulator. It's obvious that TMDs start out with a Z. If it is imposed by the emulator, it might be possible to find one that doesn't handle the models this way.
3) I recall a project that was attempting to re-inflate flattened ripped models. Don't know if it ever went anywhere. but might be worth a search.
4) If Tomba models are not standard, they're probably only slightly modified because the 3D format is largely hardware dictated. There's good documentation on the PS1 basic formats so it might be possible to find the Tomba model by searching for a crucial aspect of model. For example, the model's texture should be easy enough to locate in VRAM. I recall that TMDs reference their texture's page internally, so searching for reference to the texture's VRAM location might uncover the model.
Okay this is weird, I replied to your answer but maybe I didn't... Sent it? (It was like 4:00 AM lol)
So,
1)A really good Idea I never had in consideration, my original reply said that I was going to try it despite of the hour, and I did but I have some issues...
PSXPrev doesn't seems to work for me, I don't know if I'm using it right, I open PsxPrevLauncher.exe, give it the directory of where my iso is, check the TMD box, and scan... Then the commands window opens, theoretically scans the folder, but stays without doing nothing
Tried it with Japanese, English and Spanish versions of the game.
Also tried
-with ninja ripper (And the Pete d3d plugin on epsxe): nothing
-Jpsxdec: well, with this one I'm able to rip music and movies, but nothing else, the only difference I see is that the Spanish version has an extra loading screen.
-PsxMultiRiper: Got a TIM image of the first ps1 advice, and an unreadable TMD, milkshape says it's corrupted.
-3d Ripper DX: I think this one is the first one where I get SOMETHING. What I did was install the Pete's D3D plugin that MZ told me, and try to capture frames with 3d Ripper DX, surprisingly I got something, a crazy and flat mesh without textures... But it's something lol, I'm so far to figure out how to get anything but this made me actually very happy because I was so tired from not being able to get ANYTHING to work, I don't know why it doesn't get the textures though.
Then I did an experiment, I found a plugin for psx emulators called GpuBladeSoft which claims to actually implement the z-buffer to the emulator.
I was so excited to read that, but then I saw the problems:
It's a HELL hard to install, very unintuitive, and didn't actually managed the gui to work, but eventhough, apart of being GL based so I would need to search a gl 3d ripper... I've read a lot about this plugin and people says it doesn't actually work, so I think I will stop trying it and think another way.
2)Well, I don't know either, the I N T E R N E T comunity seems to affirm that it's the PS1 itself, but idk...
3)Any source of that project? Name or something? Tried to search but didn't knew exactly what keywords use.
4)This sadly my fault, because I know nothing about programming, and I have no time (I always try to learn actually but I'm very slow because I just can do it some short times.) so I don't know, I suppose this way would be a lot faster and easier if I wasn't so uneducated in this matters.