PLEASE HELP FAST! Need help with A6 physics

Can someine tell me how I can make a ball wich I can change the direction with the arrow buttons, but it's not supposed to roll back up a hill unless it has enough speed.
Thanks

Try the Newton Physics engine. Download the free 30mb download with the example games and documentation and there is a small demo exactly what you want. I think its called "Water".

Newton Physics Engine

I would like to do it with 3dgs
But thanks anyway

Unless somebody is working on the exact same project and wants to give you all his code (unlikely ) we are going to need more details from you.

Tell us what you've done so far, what isn't working, etc. Right now we got nothing to go on.

What you'll want to do is call phent_settype and the other setup functions (phent_setmass, damping, etc)- see AUM for examples. Then you'll need a while loop where the keys are checked and phent_addforceglobal is called to push the sphere around. You might find some code snippets by searching in this forum.

ok, thanks
What I need is a simple physics code with wich I can simply control the pan of a Physics entity and I don't want a ball to roll back up a hill, or go forward without force from a downhill roll.

To control the pan, you will need to add an angular force. To do this, you use phent_addcentralforce with a veclocal off center. This will apply an off center force and effectively rotate (ie change the pan) of your ball.

Regarding your requirements that the ball not roll unless it's on a hill (Guessing something like Marble Madness perhaps? ), then as long as gravity is set within the Physics Engine, this is exactly what will happen.

Yes, It was called Marble maddnes
This is my code I'm using:

Code:

---

 
action ball
{
	p_player=my;
	my.shadow=on;
	phent_settype(my,PH_RIGID,PH_SPHERE);
	phent_setmass(my,5,PH_SPHERE);
	phent_setfriction(my,40);
	phent_setelasticity(my,40,10);
	phent_setdamping(my,20,20);
	var dir[3];
	while(1)
	{
		vec_set(dir,nullvector);
		if(key_a)
		{
			dir.x-=1;
		}
		if(key_d)
		{
			dir.x+=1;
		}
		if(key_w)
		{
			dir.y+=1;
		}
		if(key_s)
		{
			dir.y-=1;
		}
		vec_rotate(dir,vector(camera.pan,0,0));
		vec_normalize(dir,80*time);
		phent_addtorqueglobal(my,dir);
		wait(1);
	}
}

function initialize_physics
{ 
	ph_setgravity(vector(0,0,-380));
	ph_setcorrections(20000,0.1); //60000 0.01
}



function main()

{
	initialize_physics();
	load_level("lvl1.wmb");
}
 

---

But with that the ball rolls back up the hill. Where do I change that?

Try decreasing torque or increasing gravity.

No, that doesn't work
I tryed both.

can no one help me?:(

Would the physics (no real physics) of MandrinPinball work for you? HM... BAd idea.... Real physics are better if you can use them.

EX Citer

Can you mail me your level & code ? mgrubert@conitec.net

It's really just a matter of playing around with the numbers until the ball acts the way you want it to. Reducing friction and torque are a good start but if your level planes have different slopes then obviously the setting that just about keeps the ball from rolling up the steep slope will allow the ball to easily climb a shallow one.

A couple of ideas:
Compare current and previous z position. If z has increased then apply a force from current to old position or even better add a counter-torque that slows down the ball so that it can't move on in this direction. Also check the current rotational speed and stop adding torque if it's above a certain threshold.

have you taken a physics class? if you did, think about how a force is broken up into components, and set the up component to the up key, the down component to the down key, and so on. and set this into a while loop.
if you don't know how to break it up into comonents i will help you out. but i will not spill my ball code just like that tho! it took me a while to figure it out!

Alex

Thanks for all the help.
I think I can solve the problem now. And otherwise I'll ask again.