Damping conclusion correct.
Actual values for damping will need to be played for each projectile type.
In actuality the damping caused by air-friction will be higher at greater speeds too, there will be a bit of fudging required here I think.

But we still want to keep the mass values correct to start with,
so that our 'correct' gravity gives them a 'correct' trajectory.

I believe the velocity rate is in quants per second, but Im no physics guru...
So the formula you have for it is correct.
BUT, if the velocity is in quants per physics-frame, we will need to multiply it my 'time_step'.
Once again, Im no physics guru, and I couldnt find an answer one way or the other in the manual.
But 800,000 does sound high, but I dont remember 800 * 100 = 800,000??

Heheh, there I go with bad math.

Btw, I just realized 10cm = 1 decimeter (an actual metric unit). ;D

So if the real Panzer IV was 6.62m long, 2.88m wide, 2.68m tall, then I need to make it:

66.2 x 28.8 x 26.8 (quants)? Were you just estimating dimensions earlier?

Simply multiplied by 10 to get decimeters, or in "game talk" our quants.

Oh, the terrain is done. I made it 5000x5000 in WED for simplicities' sake:

5000q = 50,000cm
50,000cm = 500m

I wanted 5km, so:

5000/500 = 10

So I scaled the terrain by a factor of 10 in WED, making it 50,000q.

EDIT:

Heh, my modeler is good. Changed the height to "real life" dimensions on our quant scale, hit tab, and the other eral life dimensions popped up for width and height, give or take a couple mm.

I done the some decimeter<->centimeter fumble in my previous ramblings.
But I was estimating into round number to some degree too.

Looking it over, you are right, the tank will be 66.2 quants etc.
But damn, its a bit under the 3DGS standard of 80 quants being a collision "hull".
We may need to rescale if our bullet/shell collisions start to fail at close range(hi-speed).
But as youve seen, its not that hard at this early stage.

And in a pinch, we could also re-scale any models in-game, like we are doing with the terrain.
Its the in-game quants that are the important ones when it comes to collision hulls.

Understand.

I think it's going to work now though. This is MUCH larger than before, and only some of the MG bullets (which are MUCH smaller than the 75mm maingun rounds) weren't detecting collisions. The main gun bullets worked without fail, every time.

Ugh... Switched over to the new map and models, and for some reason, the tank is just floating in mid-air. There must be something wrong with the code that's not registering it as a physics entity. Don't know why... I'll have a look.

Ah, that was the level... I'll need to re-do it...

NOOOO.... maybe
Its just in the main function you create the tank at a position of vector(-225,-848,460).
Thats now different because of the scaling.
Just change its create position and it will be fine.
It probably got created "underneath" the terrain, and terrain is invisible from behind.

No, I had to the level off center. I had already compensated for the new scale. I just centered it in WED and in works fine now.