Hull Down on reverse slope

[Guest ciks]

Image is worth of thousand words:

After playing one scenario where my Panzerschreck missed 3 shots at Churchill in similar conditions only about 10 meters closer, After that I made a small test scenario screenshots is taken from. (elevetion numbers are: 8 - for the base of house, 9 - in the middle, 10 for the top of slope)

After that I lowered elevation settings for top part to 9.

And you see that % to hit jumped from 51% to 89% which is reasonable for this distance.

Is there some logic behind it? The only "hull-down" I can think of in first example is that hull top is partialy "hidden" behind turret...

[This message has been edited by ciks (edited 04-04-2001).]

[Dschugaschwili]

This looks strange indeed. I wonder what BTS has to say about this...

Dschugaschwili

[Sten]

It is also possible that the tank was considered "cresting".

Since you created a very steep slope, you would of course see the front of the tank while the tank was still climbing up said slope. During that time it would be reasonable to consider it "hull down" since only part of the tank was visible.

If the picture was taken immediately after the tank switched from going up the hill to going down the hill, towards your 'schreck it is possible that the "hull down" status had not yet changed.

That should change within a few tenths of a second.

Take a look at the movie again. Does it change?

Sten

[Quenaelin]

I don't know exactly how hulldown mode is calculated, but I think there is somekind of algorithm to calculate when tank is in hulldown position. I am suggesting simulation approach to CM2, so that round trajectory is actually calculated and it's effect to any obstructing objects on its way is calculated also, such as hitting to crests, trees and houses, so these kind of mistakes cannot happen anymore in CM2.

[Guest ciks]

It is also possible that the tank was considered "cresting".

if so then it is some kind of graphical engine"bug" or miscalculation.

If the picture was taken immediately after the tank switched from going up the hill to going down the hill, towards your 'schreck it is possible that the "hull down" status had not yet changed.

That should change within a few tenths of a second.

Take a look at the movie again. Does it change?

You can't give target command during the movie, can you? As you can see screenshot is taken during Orders Phase.

[This message has been edited by ciks (edited 04-04-2001).]

[Jeff Duquette]

Great Images CIKS. Another prime example of why 3D TAC wargames should be moving away from traditional "To Hit" table calculations and simply model actual round trajectorys for tank main-guns, ATG's etc. Incorporate Real World TM trajectory and real world round interaction with the 3D terrain model and you eliminate all these artificial methods of trying to model hull down positions. Just my two cents. It's coming...we just wont see in CM, CM2, GI Combat etc.

[Panther131]

Lets cross our fingers for CMII. I really hope so.

[SenorBeef]

Re: ways of figuring out hull down.

A simple an effective system I can think of, which I don't know if they use or not, is simply taking an LOS from the top (turret) of the tank. If its clear, check the bottom (hull), and if thats blocked, then you're hull down.

[Micheal Wittman]

Also, let's consider scaling.

The size of the unit on the landscape may

confuse things in relation to actual distance. I'm not saying that this is defenitly the case here. But one example may

be one thread in which somebody was talking

about seeming to run men over with an amour

unit, ( although this isn't modeled in "CM")

visualy it may look like it. But true scale

would indicate that the units were somedistance from each other.

But we can look at "CM" as a work of Art that's being improved upon.

That's 2 cents of my worth.

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"Is this thing loaded!"

[Jeff Duquette]

Re: ways of figuring out hull down.

A simple an effective system I can think of, which I don't know if they use or not, is simply taking an LOS from the top (turret) of the tank. If its clear, check the bottom (hull), and if thats blocked, then you're hull down.

Any improvement would be better than the present treatment of hull-down. Hull-down seems to be a reoccurring problem as far as modeling its impact correctly in wargames. Similar design challenges appeared to exist with all incarnations of CLOSE COMBAT. COMBAT MISSION seemingly faces challenges of its own in this regard (consider again the Images posted above).

My basic contention is that modeling weapon trajectory that interacts with the 3D terrain model would be one approach to solving the predicament. Of course vehicles surfaces would have to be modeled in 3 space as well. Scratches Head…lots of variables…however vehicles are already interacting with the 3D terrain model…ala a Truck can’t drive through a building; Vehicles in CM can push KO’d vehicles off bridges; Vehicles can become bogged in soft ground etc etc. Seems like the basic ingredients are there…but than I dont write code…so again I am talking from the hinnie (my programming skills are sadly limited only to the basics of FORTRAN and…uhhh…BASIC).

I expect with the increase in sophistication of computer wargames we have been seeing over the last 10 yrs, we will continue to see progressively more accurate modeling of terrain, vehicles, environmental conditions, etc. (Think of the differences between that old classic Steel Panthers relative to Combat Mission or Close Combat).

[Harold Jones]

Hull down and its attendant benefits has very little to do with weapon trajectories. Hull down is primarally a line of sight issue. The other factor is the terrain feature that is covering the hull. For instance a perfect hull down position would expose a tank only from the bottom of the maingun to the top of the mantlet. This would give minimum exposure of the vehicle and make it both harder to spot and harder to hit(a frontal shot at a Sherman turret is a much harder target than one at the entire vehicle front). In addition to line of sight benefits, the type of terrain feature you are using is important because what you are hulldown behind should provide cover as well as concealing the hull it should be something that the enemy can't simply shoot through (hedges, sand berms, wooden fences etc.) To calculate hulldown you would have to calculate the line of sight from the muzzle of the main gun to the location you are checking. If I remember correctly CM in its current incarnation doesn't do this but instead calculates from the middle of the vehcle.

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If something cannot be fixed by hitting it or by swearing at it, it wasn't worth saving anyway.

[Jeff Duquette]

Hull-down has everything to do with incoming round trajectory. A tank which has its hull concealed by a crest line of a hill will not typically get hit in the hull. Why? Because the trajectory of a round being fired across that crest will impact the earth making up that crest line long before it can come in contact with its intended victim. A round that just manages to squeak over the Crestline will hit the hull-down tank in the turret.

Harold Said: line of sight from the muzzle of the main gun to the location you are checking

Yes…this would be what is commonly referred to in exterior ballistics as a rounds “trajectory”. Think of it as the path a round takes from muzzle to target . If a hill is in the way of the incoming rounds path than the tank behind that hill doesn’t get hit.

Harold Said: If I remember correctly CM in its current incarnation doesn't do this but instead calculates from the middle of the vehicle.

I think if you go back and examine some of Steve’s past postings on this subject, you will find that the little tracer elements you see streaking across your virtual battlefield are simply eye candy…game drama. Weather a round hits or misses a target has nothing to do with the tracer element eye candy. The games engine has already determined a hit or miss before you even see your tank fire. The “To Hit” percentage is simply an amalgamation of various factors such as: crew quality, target size, cover, etc. all boiled down into a basic percentile.

This is why you see such odd game occurrences like a gun hitting a target (say a tank) with perhaps its second round…yet the “eye candy” tracer element of the third round down range at that same target can literally go wide right, or wide left by as much as 200 meters. Stationary Target…Stationary Firer. This much round lateral dispersion at normal combat ranges of WWII tank engagements would quite literally be outside the field of vision of most gun sights. But it has nothing to do with weather a tank is bracketing its target…or has its target “zeroed” in. Added accuracy from bracketing or zeroing is rolled into a handy “little” bonus tacked onto your “To Hit” percentile. And for the local zealots this is not a criticism of CM...it is simply a detached observation.

[Guest ciks]

Also, let's consider scaling.

The size of the unit on the landscape may

confuse things in relation to actual distance.

In these particular screenshots units were not scaled.

On size of the unit.e.g. graphical representation:

Yes it may confuse things, for example, engine "thinks" unit is still somewhat behind a crest, but it is graphically represented as already over the crest. Can be. But shouldn't, because GRAPHICAL REPRESENTATION is EVERYTHING to us, players. We make our decisions and orders according to graphical representation, not mathematical engine calculations.

[Matthew_Ridgeway]

ciks: because GRAPHICAL REPRESENTATION is EVERYTHING to us, players.

Exactly! This issue of game engine calc’s vs. visual representation has reared its head before. A recent topic by Marcus Hofbaur revealed another such quirk in which vehicles were being shot at and hit when graphically they appeared to be a large building intervening between the firing unit and target. The images on that thread also told a thousands words.

Relative to the images you posted, it is impossible to see how graphical scaling can be the predicament here. The Churchill (at least graphically ) is literally over the slopes crestline, and thus should be presenting the entire tanks cross-section as a target to the schreak team. Hard to figure how the image you presented could be a hull-down situation.