CustomMultiBodyVehicle Joint

[PJani]

NICE! . I would upload something to, but i am at home and i dont have much up bandwidth :/. Something similar to your tank, but with 12 wheels.

[Scarabol]

Thx, im using following vars for the "tank".

Code: Select all

   NewtonWorld * nworld = NewtonCreate();
   float minSize[] = {-2000.0f, -2000.0f, -2000.0f};
   float maxSize[] = {2000.0f, 2000.0f, 2000.0f};
   NewtonSetWorldSize(nworld, minSize, maxSize);
   int defid = NewtonMaterialGetDefaultGroupID(nworld);
   NewtonMaterialSetDefaultFriction(nworld, defid, defid, 1.0f, 1.0f);
   NewtonMaterialSetDefaultSoftness(nworld, defid, defid, 0.0f);
   NewtonMaterialSetDefaultElasticity(nworld, defid, defid, 0.0f);

   // Dont forget this or the tank stuck in ground after some time
   NewtonBodySetAutoSleep(tank.body, 0);

   float movespeed = 10000.0f;      // Im using this for each wheel like vehicle->ApplyTireTorque(i, movespeed);
   float breakspeed = movespeed*2;

   float mass = 1000.0f;      // mass for tank body
   float tiremass = 250.0f;
   float radius = 0.45f;
   float width = 0.6f;
   float susplength = 0.35f;
   float springconst = 1.0f;
   float springdamper = 5.0f;


These are my values for the moment. The driving handle is quite nice, but not finished yet. Tank mass is to low, tiremass to high, comming soon.

MfG
Scarabol

[collerblade]

Hi all

i have problems with my multibodyvehicle too.

Here is two videos from my car:

There is only forward torque.


And now only backward.


There is no other force. Why it goes right? (or left?)

[Sash]

Hi all
There is no other force. Why it goes right? (or left?)

Just an usual slip. Because of lack of grip steering (what makes vehicle to maintain commanded direction) does not work.
Try less throttle (tire torque) - and vehicle control will be restored.

Btw. Nice grass. What is your graphic engine, Ogre ?

[collerblade]

Ok. Everyone like grass.
No, its my own graphics engine.

But what about the cars behavior?

CollerbladE

[collerblade]

Hi all

I finaly managed to implement custommultibodyvechicle. I was very happy .
But i have another problem. Maybe someone solved it already.
The car is very slow. It can't go faster then 60km/h, no matter how mutch torque i apply to the wheels. Bigger torque helps to accelate the car faster, but the maximum speed reamins the same :S. That is very unrealistic i think. I tried everything. Change the the torque, the friction of the tires, mass of the car/tire, etc.. And only one thing helped: the radius of the tire. If i incrasse this radius, the car goes faster. But my car isn't a monstertruck. I wanna use a normal tire radius (about 0.3m).
What did i wrong ?
Plz help me.

UI.: i tried Dave's megademo10, there is a multibodycar implementation (it works fine), but i cant figure out the parameters. And i can't reach him.

[ledahut]

I am not sure [I did not used vehicle at the moment] but maybe reduce linear and angular damping.

[PJani]

Hi all

I finaly managed to implement custommultibodyvechicle. I was very happy .
But i have another problem. Maybe someone solved it already.
The car is very slow. It can't go faster then 60km/h, no matter how mutch torque i apply to the wheels. Bigger torque helps to accelate the car faster, but the maximum speed reamins the same :S. That is very unrealistic i think. I tried everything. Change the the torque, the friction of the tires, mass of the car/tire, etc.. And only one thing helped: the radius of the tire. If i incrasse this radius, the car goes faster. But my car isn't a monstertruck. I wanna use a normal tire radius (about 0.3m).
What did i wrong ?
Plz help me.

UI.: i tried Dave's megademo10, there is a multibodycar implementation (it works fine), but i cant figure out the parameters. And i can't reach him.

I can remember the same thing was happening in old 1.53 newton. Only bigger tire radius helped, its looks like the angular speed is clamped.
Angular and linear damping should not have so big impact on speed. If am right the damping is only ratio which "lowers" the speed.

U can try setting linear and angular dampening to 0, but i think it wont help.

[collerblade]

Then why is it works in Dave's megademo10 ?

[PJani]

I am not sure why.

Julio might explain the secret.

[Sash]

So, any improvements with MB or RC vehicles in 2.25 ?

[ruslannow]

Hi!
Here is my car (Hinge Joint, Slider Joint)
-------------------------
Material wheel:
friction static 1
friction kinetic 1.25
elasticity 0.1
softness 0.05
-------------------------
Management:
R - reset
C - camera
Space - handbrake
arrow keys
mouse - rolling camera
-------------------------

what do you say?

http://depositfiles.com/ru/files/ge1dulbua

[Sash]

Looks good (except I'd prefer stiffer suspension), but wait....
Is it MultyBodyVehicle class, or you just assembled your own vehicle with bodies and "standalone" joints ?

Dont you have a video rendered with debug (wireframe) display, to see how this works ?

[PJani]

I think he over setted friction. if he used multibodyvehiclejoint..

[JernejL]

ruslannow: that's pretty impressive, good job, the only thing i notice wrong is, that the suspension has no top limit - wheels go thru chassis.