I''d like some info on this too, I just added collision detection into my engine and want to get the physics working right.

Morgan

Hey guys,

I dont want to flame you but, USE your head !!

To implent physic system in a game, you must use Vector Math.

Each mesh (3d object) mush have a struct for physic properties,
like (weight, deform(witch make a object bounce high or low when it's collide with something, like a superball), (you can put anything you find interresting for your game, nothing is predefined, its belong to each game designer to include what he/she tought is interresting for them in their game).

After you must have a VectorMomentum (force accumulated by an object), VectorForce (this is a vector that pointing where the force received from an object is).

Like if you got a plane sim, your plane is affected by gravity (this is a vector pointing straight down to the ground), you got the power of the engine that push the plane where is nose is), you got the drag force (this is cause be the air friction on a plane; more something is aerodynamic, the less is affected by drag. And finally you got the Vertical Ascension (this is calcule by the Speed * The Plane Portance). So if you add all those Force Vector, this will give you ONE vector that tell you where the plane is going.

Lets say you have a JetFighter, it's speed is extremely fast, so is portance too, but engineer have work very hard to reduce drag, so it will accelerate very fast (and can go faster then a normal plane), for the Gravity, this is a constant vector always pointing straight down, so even if your plane is rolling, it's always be pulled down by gravity.

Add them togother, Using Momentum, VectorForce & time, you will got a good physic engine.

I give you a clue here, i think is Einstein that've say that:
"Action = ReAction" !!

That's why the thrust of the engine witch is pushing back, make the plane go straight-foward.

Check in "www.gamasutra.com", that have a plentty of good Tuts, on physic engine. But the basis, remain the basis.

Happy Coding,

LowRad

Edited by - LowRad on June 8, 2000 10:36:47 AM

You have to break the vectors down into their individual componets first before you can add them.
You need to come up with a standard coordinate system then see how much force in the x direction, then in the y direction, then in the z direction. To keep my example short i will use only x and y.

vector_force = 1;vector_angle = .785;  // about 45 degreesx_force = cos(vector_angle)*vector_force;y_force = sin(vector_angle)*vector_force; 

"Now go away or I shall taunt you a second time"
- Monty Python and the Holy Grail

I''d kind of like a link to a good site which explains the math, very simply, for the physics. I know how physics work (I fallen over enough times to figure that one out), I just want a tutorial of some type for physics (I haven''t takes physics in a while and I didn''t take very good notes the first time around).

Morgan