Armor, does CMBB know specific angles?

[ww2steel]

Okay, I know that CM1 takes into account obliquity (the angle of the target vehicle armor to the attacking gun). This makes a tank that is armored equally on all surfaces hardest to penetrate at a 45° angle from the firing vehicle. Does it treat everything like a KV (turret and hull are squares as far as computations are concerned) or, does it take into account things like:

The Tiger's turret is round (viewed from top)? Does a shot to the side of Tiger does it give you the same effect as a 'curved' plate as it should?

The IS3 has a pike nose (actually hardest to penetrate from direct front - unusual)

I could figure this out using hundreds of tests, (I may anyway) but if someone already knows...

Thanks,

Mike

[Renaud]

CMx1 has a of 'curved' setting to simulate that. It only applies to surfaces designated as such, like the bullnose on the T70, T34, KV1, IS2, and IS3 (probably many other's I'm forgetting).

The geometry of the 'curved' attribute is not specifically modelled by vehicle, but rather a generic setting. Hits on a 'curved' aspect can result in randomized 0 degree and upward angles, from what I've seen. So you can get low-angle front hits on the early-model T-34 'curved' turret front for instance, allowing 50L42 and 37mm to penetrate.

This setting does not apply to the Tiger I side, only to top-to-bottom rounded surfaces. Tiger is just treated as a 0-degree 82mm armor. I believe the +2 mm may have been added to represent this horizontal curve advantage, as the pzVI I side turret armor was really only 80mm historically.

[Redwolf]

Okay, I know that CM1 takes into account obliquity (the angle of the target vehicle armor to the attacking gun). This makes a tank that is armored equally on all surfaces hardest to penetrate at a 45° angle from the firing vehicle. Does it treat everything like a KV (turret and hull are squares as far as computations are concerned) or, does it take into account things like:

Yes.

CMx1 composes the effective hit angle from two components:

1) the target unit data, and that is always and only a vertical angle, never a horizontal one (That's why the next answer is "no" on the tiger turret side)

2) the positional angle, which has a horizontal component (you stand e.g. 37 degrees from the front) and the position on map also has elevation, modifying the above unit data. Shooting at a sloped front from above removes unit data angle.

The two components are then added (as in properly geometrically added, not just "+") to get the angle used for penetration calculation.

BTW. But the hardest is not at 45. Since the front armor is stronger it's somewhere closer to the front.

The Tiger's turret is round (viewed from top)? Does a shot to the side of Tiger does it give you the same effect as a 'curved' plate as it should?

No, see above. Unit data in CMx1 only specifies vertical, no horizontal angles. Tiger side turret is flat as far as CMx1 is concerned.

The IS3 has a pike nose (actually hardest to penetrate from direct front - unusual)

It has the curved rating, so that's well covered.

[ww2steel]

Yes, check my website (in my sig) if you would like, my graphs may interest some people. That's why I stated that an "equally armored" (I meant the same thickness all around) would give the best protection at any of the 45s. (A perfect cloverleaf on the graphs) I understand that most vehicles have the best protection around 30° from front. (A small frontal bulge with big side and rear bulges- leave the adult jokes out of this )

Also, looking at the IS3 stats in the game, the upper hull is 120@56, there is no specified curve to the upper hull. It should have an obliquity of about 20° when viewed from the front. (And the turret should be 'curved' all around, not just the front.) I figure that CM MUST model this more accurately than this, given all of the other work they did, it's just hidden in the engine and not displayed. Perhaps the IS3 turret side is 'curved' but is given a slope angle of a MINIMUM of 45°, instead of a minimum of zero, like the mantlet.

I understand that they included elevation too, which is cool. Just one more thing that says to me that they must have modeled the tanks better than two simple boxes (hull and turret) for penetration calculations. They did so much other very detailed stuff I figure they must have accurately modeled the larger shapes.

I understand that you are saying the Tiger's turret in the game, viewed from the top, is modeled as a square. I will have to test this on my 'test track', A couple of hundred shots to the 45 of the rear of the turret and a couple of hundred shots to the direct rear of the turret should yield the same number of penetrations if it is modeled as round. If it is modeled as a square, and this is done at a projectile yield of maybe 85mm penetration, there will be no penetrations at 45° to an 82mm plate (which should be VERY ROUGHLY 125mm apparent thickness).

I should have time at work today... I'll post the results.

See ya,

Mike

[ww2steel]

The results: Redwolf, you are correct. CM does not simulate the curved armor surfaces as viewed from the top.

Purpose: To test this question. If the turret is penetrated as easily by a rear quartering shot as it is from the side then we know CM keeps track of things like round turrets. If not, then it sees the Tiger turret at least as square.

Method: I used 45mm L/46, equipped with 1943 APCR. According to the closest performance equation I can get for 0° sloped armor performance, this gun should penetrate 82mm of armor at 241m. According to its stats it can do 94mm at 100m - this is where I placed the Tigers. Very few tests were needed to find the results.

Groups A: Side shots.

Of 21 shots to directly strike the Tiger's turret at 90°, all penetrated. 18 were partial penetrations, 3 were fully penetrations. All shots were APCR.

Groups B: Rear quartering shots.

The first batch fired AP only (since the computer gunners determined that APCR had no chance. 6 standard AP struck the turret side at a 45° angle, all broke up.

The second batch had the AP manually removed and only fired APCR. Of 9 hits to the turret- six struck the side and three struck the rear. All ricocheted without internal effects in the least.

Conclusion: CMBB takes round turrets to be squares when viewed from overhead.

Speculative conclusion: All armor in CM is a simple box, or pair of simple boxes if the equipment is turreted. The only angles being used by the engine are the ones shown on the data page, plus elevation differences and obliquity to the firing weapon. (Slope, 'curved', and abstracted 'shot trap')

I understand why they did it though, it's a lot of work and data storage to keep track of all that. I was certainly not looking forward to incorporating it into my penetration calculator. Since it is made to show performance in CM, I guess I don't have to incorporate it since the game doesn't!

Hope this helps,

Mike