[basic] how to make an agent move from the middle of the screen in a certain angle

Programming Questions

smvalenga

[basic] how to make an agent move from the middle of the screen in a certain angle

in Programming Questions • 1 year ago

Is there a way that i use angle instead of the x and y coordinates??

maybe a library that makes it easier?

any help would be super recognized, since i am totally new in programming and can not find a simple answer...

thanks a lot!

Replies(5)

asimes

Re: [basic] how to make an agent move from the middle of the screen in a certain angle

1 year ago

This is in response to the post you deleted.

I don't understand where the target location for each is without an image. Do you mean that they would be touching one of five sides of the circle? At a radius distance from the circle?

As far as moving the agents goes it sounds like you are not doing a grid based environment so you are going to want to get set each agent's rotation to face their target. Then move your agent in that direction. If your target was the mouse then you would set up:

for (int i = 0; i < numAgents; i++) {

float agentTheta = atan2(mouseY-agentY[i], mouseX-agentX[i]);

}

asimes

Re: [basic] how to make an agent move from the middle of the screen in a certain angle

1 year ago

This is in response to this post.

Set a speed for your agent to move at. If you picked say, 2 units per frame, then you would use something like this:

float speed = 2;

for (int i = 0; i < numAgents; i++) {

// Use a method like the one I put above to get your angle

float agentTheta = atan2(myTargetY-agentY[i], myTargetX-agentX[i]);

agentX[i] = agentX[i]+(cos(agentTheta[i])*speed);

agentY[i] = agentY[i]+(sin(agentTheta[i])*speed);

}

This assumes you know the target coordinates of your agent.

smvalenga

Re: Re: [basic] how to make an agent move from the middle of the screen in a certain angle

1 year ago

thanks a lot! if you had some examples it would be great... otherwise i think i am getting the essence!

jobleonard

Re: [basic] how to make an agent move from the middle of the screen in a certain angle

1 year ago

Is there a way that i use angle instead of the x and y coordinates??

That depends on what you want to use them for for. What is it that you really want to do? You want to move agents, right? Well, then you have moving objects. So that's trigonometry, and vectors.

So you know what? Forget about programming for a few hours and watch Khan's lectures on Newtonian physics and on trigonometry. They're pretty fun, and the fundamental understanding they'll give you will be much more useful in the long run.

It starts out very basic, so some of the stuff is probably already known to you, but it gets more advanced later on. Here's the first lecture on polar coordinates:

http://www.khanacademy.org/video/polar-coordinates-1?playlist=Trigonometry

And here's the introduction to vectors and scalars:

http://www.khanacademy.org/video/introduction-to-vectors-and-scalars?playlist=Physics

Also, if you click on File -> Examples... there's a number of example sketches. Under Topic -> Motion you will find a number of sketches dealing with motion. Those are probably worth checking out :).

PS: Are you Dutch? Because "agenten" is the Dutch translation of agents.

Massimo

Re: [basic] how to make an agent move from the middle of the screen in a certain angle

1 year ago

I think asimes gave a good answer but maybe this example is simplier and can help...

The displacement of a point according to an angle is simplier than you think and it doesn't need any library:

float directionAngle = 0; // this is in degree
float speed = 3.5; // some speed you'll add every step
PVector position = new PVector(); //a PVector is ideal to store x,y,z
void setup() {
size(640, 480);
//we move the point to the center of the screen (after specifying the size)
position.x = width / 2;
position.y = height / 2;
}
void draw() {
background(0);
//here we use radians conversion because cos and sin use radians as parameters
position.x += cos(radians(directionAngle)) * speed;
position.y += sin(radians(directionAngle)) * speed;
ellipse(position.x, position.y, 20, 20);
}
void keyPressed() {
//add or subtract the angles when changing direction
if (keyCode == RIGHT)
directionAngle += 12;
if (keyCode == LEFT)
directionAngle -= 12;
}

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