Speed Locking?

[mold999]

Is there any way to lock an objects speed to a specific direction?

Meaning, if I have an arrow:

-->

And I want it to go only in the direction it is pointing, is there any way to do this?
I would like it to work even if I rotate the arrow, like this:

/\
|

And it will start to move upwards.

Thanks,

--mold999

[Kilinich]

No easy way to do...
But you can try use one of my "wheels" for that:

Box-Wheel for top view

Kilinich

Rating:
Filesize: 19.11 kB
Comments: 7
Ratings: 3

[mold999]

Could you explain a little more about the scene?

Like the n and vn variables in the wheels, and the clamp(). Also the n and s variables in the thrusters.

Thanks,

[Kilinich]

Could you explain a little more about the scene?
Like the n and vn variables in the wheels, and the clamp(). Also the n and s variables in the thrusters.

Code for wheel:

Code: Select all

v := entity.vel;
n := [ - math.sin(entity.angle), math.cos(entity.angle)];
vn := ((v(0) * n(0) + v(1) * n(1)));
entity.vel = entity.vel - n * clamp(vn,  - entity._maxForce, entity._maxForce) * entity._airForceMult;

n - normal direction vector of wheel with length = 1
vn - velocity projection to that normal, means how fast wheel moving in "side" direction
clamp is a build-in function declared in config just a limits for value (x, min, max)

Same for thruster but instead of normal I use forward direction vector. "s" means velocity projection to forward direction, or how fast car movig forward (backward is negative) removing "side" part of velocity.

[mold999]

I was thinking...

Can't I just set the velocity of the arrow to

[Math.sin(angle), Math.cos(angle)]

And multiply by a factor to increase the speed?

I tried it, but it wouldn't work. Is there something I'm doing wrong?

[Kilinich]

My script stops wheel from moving sideways. Did you get it?

[mold999]

Yes, I got it.

But, why doesn't [Math.sin(angle), Math.cos(angle)] work? Shouldn't that just give the x and y speeds?

[Kilinich]

Yes, I got it.

But, why doesn't [Math.sin(angle), Math.cos(angle)] work? Shouldn't that just give the x and y speeds?

Result is vector pointing to direction of geom's "front" not speed