Legacy GM *solved*Angle in 3d

[Kahrabaa]

Hello.
I want two objects, in 3d, to repel each other based on their position and distance.

In 2d I would:

//Get the inverted distance between the two points (inverted cuz the repulsion needs to be stronger the closer the two objects are)
dis= 1 / point_distance( x1,y1, x2,y2);
//Get the direction
dir=point_direction(x1,y1,x2,y2);
//Accelerate
hspeed+=lengthdir_x( dis, dir);
vspeed+=lengthdir_y( dis, dir);

How would I do the same in 3d?
I found a point_distance_3d but no point_direction_3d.
My thinking is limited to 2d wich is probably why Im thinking incorrectly maybe.

One thing I tried was to move each axis independently. Like

//Get the inverted X difference between two objects
xdis= 1/(x2-x1);
ydis= 1/(y2-y1);
zdis= 1/(z2-z1);
//The add that to acceleration
hspeed+=xdis;
vspeed+=ydis;
"zspeed"+=zdis;

But this gives me incorrect behaviour. Because if the difference in Y is GREAT and the difference in X is small. They still repel each other in the X axis strongly even though they are far away wich is incorrect. This is because each axis is being affected independently. (Realised this after i tried it)

Would appreciate any help
Thank you!

 

[flyingsaucerinvasion]

You don't need to know angles for this.

var _xd = a.x - b.x;
var _yd = a.y - b.y;
var _zd = a.z - b.z;
var _force = Some_Amount * power(_xd*_xd+_yd*_yd+_zd*_zd,-1.5); //-1.5 drops with distance squared. use -1 for linear drop.
a.xsp += _xd * _force;
a.ysp += _yd * _force;
a.zsp += _zd * _dorce;
b.xsp -= _xd * _force;
b.ysp -= _yd * _force;
b.zsp -= _zd * _force;

 

[Kahrabaa]

I love being invaded by flying saucers!
Thanks alot.