tank destroyer

[adzling]

hey here's the work so far on the tank destroyer i've been blathering about.

no turret but what the hey....it IS a tank destroyer not a tank!

make 'em cheap and make 'em plenty....

as Stalin said "quantity has a quality all of it's own"

there's a couple of views + an xray view showing crew, battery and engine location

note it has a commander operated 14mm mg in a remote cupola mount (for those pesky inf)

it's kinda based off the israeli merkava in that the engine is placed up front to maximize crew surivability with the doors at the rear for easy crew exit.

+ the battery is slung as low as possible to stop yurch blasting it out all the time.

the main idea with this vehicle is to reduce silouhette as much as possible while sloping those forward facing glacis plates as much as possible (im assuming the game engine realistically handles relative armor thickness).

I've tried to avoid shot-traps as much as possible hence the rather unorthodox geometry but hey if it keeps the crew alive an extra 10 minutes it's worth it!

I'm not sure how the game models armor thickness.......anyone shed some light here?

Is it by geometry (i.e. polygon y & polygon x) or is it simply by facing (front/left/right etc)?

It would be a pity if the game simply modelled based on facing as a vehicle with radical sloping like this would be pretty handicapped by it (notice how small that flat top armor area is?).

as it is the vehicle is under 2 meters tall while retaining .33 meters of ground clearance (typical for many AFV's).

I'd see this vehicle with similar armor thickness (or possibly even slightly superior) to a thor with vastly improved sloping resulting in a much higher survivability from the front and sides when on level ground.

It would be pretty vulnerable to top shots as it moves around slopes but still superior to the completely flat top of the thor chassis.

The rear is squared off to reduce the vehicle's profile but has the detrimental effect of facilitating quick rear kills...oh well can't have everything.

[ August 15, 2006, 05:58 PM: Message edited by: adzling ]

[adzling]

oh that's a 120mm cannon it mounts

the green is the engine and the orangey bit is the battery.

i don't know if clay has established a power/weight ratio but if so i can tune the size of the interior components to match.

+ I want to add a magazine for the ammo but i'm not sure how big that stuff is and i don't even know if the magazine is an interior component in dropteam!!!

clay?

As i go forward im creating these models in sketchup and exporting...

which is nice becuase it means i can very easily build up a library of components (wheels, 14mm mg, cupola, 120mm gun, crew, smoke launchers, etc).

At some point I will post these to some place where interested folks can d/l them.

sketchup is a pretty good tool for this as there's a free version of it available from google.

+ if you have the pro version (as i do) then you can use actual real topography from all over earth (and soon the moon!) to build 3d topo maps.....can't wait to get those in-game.

Hey clay you want some REAL topo maps of Europe for the upcoming ww2 add-on? I'd be happy to build a few for you

[yurch]

A few things, much from what I've observed from other units:

The armor polygons are grouped by facing, but I think you get to determine what is what.

That is a very strong sloping. Even if that glacis had the same frontal rating of the apollo it'll be somewhat difficult to penetrate with a level shot. Giving it Thor armor would be a bit excessive, and probably wouldn't be fair to the Thor, who really pays for the armor in speed. Not to mention some of the poor bastards who have to fight your thing.

You might want to compromise somewhere between. You don't have a turret, which usually bear a lot of the protection, so you could probably make a pretty good argument for the high-end.

The square bit at the nose, though, will be a liability for the tank in close-fighting. You may want to angle it up or downwards.

Subsystems are defined as spheres. As it stands most units have the gunner/ammo in the turret, and battery/driver/engine in the chassis. Since you won't really have a turret, an ammo subsystem in the chassis somewhere would only be fair. I don't know if there's a way to link this subsystem to an external weapon, though (for disabling the shooting on loss of this subsystem). Same with the gunner.

The gun will need a slight bit of side to side traversal just to do sensitive aiming, which probably spells a tiny 'turret' located somewhere on the technical end. I'm not so sure how well multiple controlled turrets, or turrets with limited rotation can be handled yet.

Any info on this, Clay?

Edit: this thing could probably get away with Ion, 120mm, 76mm, and possibly a (direct fire?) medium mortar.

[adzling]

as far the armor facings go this can be a bit of problem as some of those armor plates face in two directions (i.e. front AND side).

yes that sloping is pretty severe.....somewhere mid-way between the apollo and thor makes sense as there's not a whole lot of room in there for big powerplant.

this might also be a good reason to limit it's speed to halfway between a thor and an apollo.

but the added armor should be compensate by a lack of turret....it should be fairly easy to get in close and zap it as the once your within 500m or so there's now way this vehicle could turn fast enough to track the target......so it's all about keeping your foe at a distance.....and being able to survive at that distance....

i'm not to worried about the flat armor between the top and bottom hull wedges.

There needs to be some balance and if someone gets close enough to target that strip of flat armor they're probably better off driving around the back or side and shooting it up from there.

pity about the sub-systems being defined as spheres only as that is a little sub optimal for squarish afv's....

yeah and the gun will need some traverse side to side...something like 15 degrees left/right and as much up/down as a thor would make sense.

play balance with a vehicle like this will be little tricky as it will require looking at the trade-offs between mobility, protection & firepower.

It's effective firepower will be greatl reduced without the turret of course....and this would be magnified the closer you are to your enemy...

[aittam]

ammo or another component at the back, by the way the two guys seat it'better to get in from the top-> this would bring the 14mm(?) fwd giving it more close combat capability

battery is huge compared to a thor unless it's an ecologically friendly trees huggers vehicle

EXCELLENT!

[ClaytoniousRex]

Outstanding work at adz's usual high level of quality!

The main problem is, as Yurch indicated, that it basically has 2 turrets. You need to mount the 120 on a small turret, even if it isn't visible, to make it work. There's no provision right now for controlling 2 turrets so in making your separate MG on top work will require code changes. That means the soonest you could see the MG working would be in 1.1.4. But you could get everything else working, even with the MG in place but non-functional until 1.1.4 (or you could mount it coaxially until 1.1.4).

For the "little turret" for the main gun, just use the <LoStop> and <HiStop> tags to limit its traverse to a small side-to-side angle. When you get the modelling finished I'll hook this up for you in a new .physicalobjectgroup so you can see how it works. Then you can tweak it more from there.

I'm not sure how the game models armor thickness.......anyone shed some light here?

Is it by geometry (i.e. polygon y & polygon x) or is it simply by facing (front/left/right etc)?

It's literally by the polygons. Your slope is really going to make a difference, so follow Yurch's lead with balancing issues.

pity about the sub-systems being defined as spheres only as that is a little sub optimal for squarish afv's....

It's not as bad as it sounds. You can make the spheres extend beyond the vehicle's interior in which case they're basically clipped by the hull. So you can fill spaces pretty effectively. Also, it's OK to be a tad abstract here (for example, don't worry much about overlaps, etc.)

[ClaytoniousRex]

You could look at the S Tank to get additional ideas for extra detail in the model, etc.

[adzling]

Aittam my thoughts are the rear clamshell doors swing open and the driver/comander seats swivel to let them enter.

I don't like the idea of my preciou crew having to clamber on top of the tank to get in and out....while under fire or after they get knocked out...

The cupola is placed where it is because it would also function as passive vision blocks (i.e windows) with 360 view in the event that the camera sub-systems fail.

haha thanks for the battery info im not really clear on the relative sizes of these thing's in the AFV's as they currently stand.

Keep in mind that this AFV is pretty small compared to the other one's in-game. It's about the size of a 76mm paladin chassis as opposed to an appollo.

I think anyhoo.

hey thanks for the ponter's clay, I'll check out the s-tank and see what's useful.

Do you have some over-all dimensions for the various AFV's currently in-game (like height, width, length)?

Yurch are you interested in helping me with the scripting/ internal component placement etc. needed to rig the model to make it work in-game?

That part isn't very interesting to me, I just like to make perty pictures...Oh and drive them around the battlfield keeling things

[adzling]

hmm that s-tank on wikipedia gives me a few interesting ideas....

considering the limitations of the tank destroyer chassis (i.e. no turret) i wonder if it would be within the realms of game balance to include a fold-up dozer blade on the chassis as the s tank has.

It would fit in well with the role of the vehicle as a defensive asset.

thoughts clay?

[yurch]

The paladin is generally bigger than the apollo, no?

I can try to help with the XML bits, sure. I'm feeling kind of useless with all this moddeling stuff (blender, bah!) that I can't even get working properly...

First question is, do you want the internals to match the other vehicles (tiny pilots, ect) or do you want to follow a, err, 'different' philosophy?

There are a few other things to consider. Most vehicles and parts have a 'destroyed' model that gets subbed in when they get blown up good. You may want to think about making one. There's also unique camos for each team in different settings, desert, woodland, ect.

I don't know what is necessary to get the track animation in and looking good, as well.

[yurch]

The subsystems generally would look like this, I think:

Not very 3d, I know.

Purple engine, blue battery, red ammo, yellow for the squishies. The battery being low centerish-mass I think keeps it in line with the other vehicles, so there won't be much confusion for the newer players. The ammo under the pilots is a bit scary, but there's not much other place to put it.

You can assign how likely a subsystem is to 'kill' the object it's in. Battery is 100%, but so is ammo, just that it's usually located in the turret. This will effectively give your tank two batteries as kill targets, which will make it a bit more vulnerable once shots start penetrating.

Personally, I think all vehicles, except maybe Thor, should have an ammo subsystem in the chassis anyway, but that is neither here nor there. We can make this ammo subsystem less likely than 100% to kill the thing if you think that'd be more fair.

[aittam]

invert ammo and battery and give ammo 75% they are in a sheltered compartment afterall and players need to develop recognition skills otherwise people would start to shoot in the low middle section of everything....

[ August 16, 2006, 10:42 AM: Message edited by: aittam ]

[yurch]

I think having the battery close to the engine and the ammo close to the turret generally makes the most sense.

There's also asymmetrical and overlapping designs that could be considered - like having the battery completely incased in the engine. Non-overpenetrating weapons like 20mm or 76mm would not be able to destroy the battery without taking out the engine first.

[adzling]

cool thanks for the input chaps

as soon as i get some rough overall dimensions on existing afv's + camo textures (sans baked-in handgrips, hatches et. al) from clay i will adjust the overall size and then we can get on with the rest of the in-game scripting.

i can easily do some damage model versions.....right now i think the only damage that is represented by swapped out model is a destroyed turret correct?

in this case i would see the area around the gun/ ammo exploding outward leaving a big hole in the side/top of the afv.

next up im happy to model you a light MBT per your post yurch.....if you have any visual starting points (i.e. afv like you'd like to see ripped-off) post 'em.

I'd also like to do a small tracked carriage that could mount some of the existing small turrets (76mm, 20mm or similar small weapon).

i.e. sheridan type thing sans the aluminum armor

[aittam]

Originally posted by yurch:

There's also asymmetrical and overlapping designs that could be considered - like having the battery completely incased in the engine. Non-overpenetrating weapons like 20mm or 76mm would not be able to destroy the battery without taking out the engine first.

fair enough, i wasn't looking too much into logical design but rather in game play

[yurch]

There are destroyed models for the chassis too. Not sure of the criteria for what swaps them in, but it's more common for really 'good' hits, like a hurricane shell directly to the battery.

The Merkava mentioned earlier is an excellent starting point, both because of the crazy sloping all over it and the futuristic look it has. (by the way, does anyone know how/where the 60mm mortar works on that thing?) Merkava looks to be a pretty dang big tank, though.

Thor has a front/side/rear/top rating of 300/150/125/150 and 400/150/100/75 for the turret. If, for the light MBT, I set the standard at 200-250/100/75-100/100 and 300/100/50/75, what's really going to hurt the thing are the sides. We all know how bad the Thor's sides are already.

Most modern MBT's of course appear to be designed with as much frontal protection as possible. Our fights are considerably more 'urban', though.

Your 'challenge' will therefore be to make a tank Thor sized or slightly smaller (with dramatically poorer armorings) that can survive in dropteam's crazy combat areas without losing it's turret in short order. You may want to go for one of those lemon-shaped turret deals the T90 has, at least for the sides.

However, it's a lesser known fact that the Thor turret can be penetrated with 120mm AP from the front at the flat bit under the turret.

So... don't forget the front.

[aittam]

the light mortar is in the turret: http://www.israeli-weapons.com/weapons/vehicles/tanks/merkava/MerkavaMk3.html

here you can see a bigger hatch: http://www.israeli-weapons.com/weapons/vehicles/tanks/merkava/MerkavaMk4.html last pic

[adzling]

rgr all that yurch, yeah the thore sides suck, strafing them with a 20mm is pretty deadly.

I'm sure i can get some really nice sloping going on the challenge is to make the internal components relative size reasonable enough as in physical terms they are the only constraints on internal volume.

power output/ weight power ratio would be helpful info to determine those factors.

in their absence we'll have to settle with tweaking the vechicle's size, speed and armor ratings to make it play-balanced.

aittam i can't see the mortar launcher....i see the smoke launcher at the front but the 60mm on the mk4 is meant to be able to be reloaded from the interior!!!

you have any kind of afv you'd like to see?

when i'm done with yurch's light mbt i'll build you one too

adz

[yurch]

Heh, wonder if clay wants to be coding crazy pop-out animation events for weapon selection...

[adzling]

huh?

[aittam]

edit: i thought was in the larger hatch but that the gunner mhhhhhhhhhhhh, in the mk3 there a hole on the to p in the drawing....... i can't find a blueprint........

[Jalinth]

I really like the TD. I can't wait to see it in game.

As for future AFV's, I've been thinking about something small with a nice low centre of gravity. Used for very steep terrian. I've got a couple maps that I've been playing with and some of them are rathr... steep in places. Mountian Goat kinda steep.

[yurch]

Originally posted by adzling:

huh?

There's a large hatch on the left side of the turret, that may have to be opened before the mortar can be used.

Provided, if that's where the mortar even is.

[adzling]

ok here's a first shot at the medium tank (or light mbt) based on the merkava

you'll note it's based on the same chassis as the tank destroyer (notice a theme here?)

i made a change to the shot-trap on the front glacis that yurch pointed out.....reducing it from about 20cm to about 2cm (i think).

even though they both use the same chassis the destroyer should carry more armor as it doesnt have the extra weight of the turret and mechanism to deal with so it should retain an advantage when deployed correctly.

next is to add a dozer blade to the destroyer....this just makes so much sense to me i have to add it

when i get relative gross dimensions on existing afv's from clay i'll tweak the some more as i suspect that the afv's in dropteam are a *little* over-sized by comparison.

the height of the medium tank is 2.4 meters and the destroyer is 1.9 meters which seems about right for them compared to current afv's.

note: the legs of drive in the medium tank poke through the bottom of the chassis only because he's a mannquin, a real bloke would be sitting with his legs forward like a race-car driver

[ August 16, 2006, 03:33 PM: Message edited by: adzling ]

[yurch]

Might want to slide the turret forward to at least where the sloping starts, otherwise you won't be able to angle the barrel downwards at all.

It's also not necessary to model the barrel, as dropteam already has models for these. If you leave it empty we can sub in whichever we want for different varients. Remember the turret is a different file, too.

Interesting idea using the 'same' chassis, I like the little slant on the chassis rear.