I don't think you should commit a model to my design just yet. It should probably be the other way around, especially if you got a perticular kind of tank in mind.
Since I got this ahk script working nicely now, I'm adding a bunch more wheels.

wow, looks pretty good!
is this going to be like that tanki online mmo?

( www.tankionline.com  )

Sweet  it just keeps getting better & better

I like the mouse zoom, nice job.

Just a note..

The over-all size of the tank/boat is getting a little large, i hope making it smaller wont through off the scriping ?

I like the mouse zoom, nice job.

Thanks

Moving the wheels would throw off the physics a little, but they're off anyway, as you noticed ... what width/length should the wheels be apart, and what radius, to fit your model? Or, you could post your model and then I'd use it instead of the boat.
Is there a particular kind of tank you've got in mind?

You've probably read this thread - I wonder if just one rigged skinmesh for the whole tank and treads could be used, with nodes in the skinmesh that could be linked/positioned to the wheels' positions. I think ragdoll simulation does something similar.

That's about the size of the sportscar. It's a small tank.
Any chance you know how to make a matching rigidbody?

Done for now. Check it out.

I like it. Is it gonna be a custom concept tank, or something real-world?

No problem.
I updated the turret control script. Fixes the sprite for the turret's look-at point, so it doesn't freeze when looking to the sky. Also makes explosions in the sky too.
Maybe for a final multiplayer product, explosions could be scheduled in a list, delayed by distance./// objects script interfaces with

int objTarget= OBJ_308;

int objTurret= OBJ_0;
int objGun= OBJ_22;

int objCar= OBJ_44;
int objCam= OBJ_66;

int objSprite= OBJ_352; // i3DLocationToScreen(Vector3,Vector3,Int Object)

// objects to test with iObjectScan in bool scanFromObject(int obj)
int objTerrain= OBJ_88;
int objBall= OBJ_132;
int objRandomCar= OBJ_264;
int objRandomCar2= OBJ_286;
int[] testObj= {objTerrain, objBall, objRandomCar, objRandomCar2};

int objPrnDist= OBJ_176;



void boom(Vector3 loc) {objPos(OBJ_220, loc);iObjectStart(OBJ_220);} // position and trigger explosion sound

void valPrnDistance(float v){OUT_176= v;};

void spriteToTarget() {
float s=0.5;

Vector3 vScreenCoords;

i3DLocationToScreen(vScreenCoords, contactPoint, objCam);

iObjectLocationSet(objSprite, vScreenCoords);
float dx= iFloatAbs(vScreenCoords.x);
float dy= iFloatAbs(vScreenCoords.y);
s= iFloatSqrt(dx*dx+dy*dy);
s= (s<1)?(1.0-s)/2.0+0.5:0.5;

s= iFloatSqrt(s);
iObjectScaleSet(objSprite, vecLen(Vector3(1,1,1), 1.7*s));
OUT_352= s;
OUT_353= s;
OUT_354= 1.0-s;
OUT_355= 1.0-s;
}


///

Vector3 vecLen(Vector3 v, float l) {iVectorLengthSet(v,v,l);return v;}
Vector3 vNorm(Vector3 v) {iVectorLengthSet(v,v,1);return v;}
Vector3 vecRot(Quaternion q, Vector3 d) {Vector3 r;iVectorRotate(r,d,q);return r;}
Vector3 objPos(int obj) {Vector3 l; iObjectLocation(obj, l); return l;}
Vector3 objPos(int obj, Vector3 v) {iObjectLocationSet(obj, v); return v;}
Quaternion objRot(int obj) {Quaternion q; iObjectOrientation(obj, q); return q;}
Quaternion qMul(Quaternion q1, Quaternion q2) {Quaternion qt;iQuaternionMultiply(qt,q1,q2);return qt;} // q1+q2
Quaternion qDelta(Quaternion q1, Quaternion q2) {return qMul(q1, qInv(q2));} // q1-q2
Quaternion qInv(Quaternion q) {return Quaternion(q.x,q.y,q.z,-q.w);} // -q
float angleWrap(float a) {while (a<-180) a+=360; while (a> 180) a-=360; return a;}
float sign(float n){return n<0?-1:n>0?1:0;}

Quaternion VectorOrientation(Vector3 v){
Vector3 v1,v2;
iVectorLengthSet(v1,v,1);
iVectorLengthSet(v2,v,2);
return QuatGetLookAt(v2-v1);
}
Quaternion QuatGetLookAt(Vector3 direction){
Vector3 up = Vector3(1,0,0); 
Quaternion orientation;
iQuaternionLookAt(orientation,direction,up);
return orientation;
}
float asin(float value) { // aka, R_asin
iDLLArraySet(0,value);
iDLLCall(MathDLLHandle,"asin",0);
float f = iDLLArrayGet(0);
return f;
}
float acos(float value) { // aka, R_acos
iDLLArraySet(0,value);
iDLLCall(MathDLLHandle,"acos",0);
float f = iDLLArrayGet(0);
return f;
}
float atan2(float value1, float value2) { // aka, R_atan2
iDLLArraySet(0,value1); iDLLArraySet(1,value2);
iDLLCall(MathDLLHandle,"atan2",0);
return iDLLArrayGet(0);
}

///
/// GForceImposters


int[] gfiObj= {OBJ_242, OBJ_154, OBJ_198}; // particles & G-Force
int gfiObjs;

Quaternion qGFI;
void GForceImposters_init() {
gfiObjs= gfiObj.length();

for(int j=0;j<gfiObjs;j++) {
iObjectImpostersCreate(gfiObj[j],1);
iObjectImposterHide(gfiObj[j],0);
}

iObjectOrientation(gfiObj[1],qGFI);
}
void GForceImposters_deInit() {for(int j=0;j<gfiObjs;j++) iObjectImpostersDestroy(gfiObj[j]);}
void GForceImposters() {
for(int j=0;j<gfiObjs;j++) { // position & show imposters
iObjectImposterSet(gfiObj[j],0,qGFI,contactPoint);
iObjectImposterShow(gfiObj[j],0);
}

boom(contactPoint);
}

bool key, _key, rKey;
bool triggered() {_key= (IN_110 > 0); rKey= _key and not key; key= _key; return rKey;}


/// scanFromObject
///

float scanRange= 2048;
Vector3 contactPoint, contactNormal;
float contactDist;
bool scanFromObject(int obj) {
bool contacts;
Vector3 scanOrigin= objPos(obj);
Quaternion q= objRot(obj);

Vector3 vScan= vecLen(vecRot(q, Vector3(0,0,1)), scanRange);
contacts= false;
contactDist= -1;
contactPoint= scanOrigin+vScan;

Vector3 rContactPoint, rContactNormal;
float dist;
int arrayLen= testObj.length(), i, nContacts;
for(i=0;i<arrayLen;i++)
if (iObjectScan(testObj[i], scanOrigin, vScan, 0, rContactPoint, rContactNormal)) {
bool isCloser= contactDist>(dist= iVectorLength(scanOrigin-rContactPoint));
if ((!contacts) or isCloser ) {
contactDist= dist;
contacts= true;
contactPoint= rContactPoint;
contactNormal= rContactNormal;

nContacts+= 1;
}
}
   
return contacts;
}

///
/// setTurretRotation
// Actuate hinge motors to rotate the turret and pitch the barrel

void setTurretRotation() {
Vector3 v;
float AngleX, AngleY;

v= vecRot(qDelta(qTarget, objRot(objTurret)), Vector3(0,0,1));
AngleY= 15*angleWrap(57.29578231*atan2(v.x, v.z));

v= vecRot(qDelta(qTarget, objRot(objGun)), Vector3(0,0,1));
AngleX= 15*angleWrap(57.29578231*atan2(v.y, v.z));

if (iFloatAbs(AngleX)>60) AngleX= sign(AngleX)*60;
if (iFloatAbs(AngleY)>60) AngleY= sign(AngleY)*60;

AngleX= iFloatAbs(AngleY)<120?AngleX*((120.0-iFloatAbs(AngleY))/120.0):0;

OUT_310= AngleY;
OUT_332= AngleX;
}


///
/// Turret Control

Quaternion qTarget;
int MathDLLHandle=0;   //   atan2 needs RadMath2.dll
void Main() {            ///   Main   
if(iInitializing()) {
MathDLLHandle = iDLLLoad(".\\3DRad_res\\objects\\Script\\RadMath2.dll");
if (MathDLLHandle==0)
MathDLLHandle = iDLLLoad(".\\3DRad_res\\objects\\Script\\RadMath.dll");

qTarget= objRot(objCar);
GForceImposters_init();
} else if (iDeinitializing()) {
if (MathDLLHandle != 0) iDLLUnload(MathDLLHandle);
GForceImposters_deInit();
} else if (MathDLLHandle != 0) {
// Determine position and distance of what's at screen center
Vector3 targetContactPoint;
float targetDistance;
if (scanFromObject(objCam)) {
valPrnDistance(targetDistance);
iObjectShow(objPrnDist);
} else
iObjectHide(objPrnDist);
targetContactPoint= contactPoint;
targetDistance= contactDist;

// qTarget= (targetDistance>-1) ? VectorOrientation(vNorm(targetContactPoint-objPos(objTurret))) : objRot(objCam);
qTarget= VectorOrientation(vNorm(targetContactPoint-objPos(objTurret)));

setTurretRotation();

// Determine position and distance of what the cannon is aimed at
scanFromObject(objGun); // get impact point
spriteToTarget();

// if firing a shot, not at nothing, create an explosion where the cannon is aimed
if (triggered()) // and targetDistance>-1)
GForceImposters();   // create explosion at target point
}
}Side note: At a range of 4096, explosions weren't visible in some parts of the sky. The sky is indeed a box. And we're on a turtle. A really big turtle. Ok not that big.
Seems to be a box between 7000 and 8000 units in diameter. File that under trivia.