# Question for PeasyCam: Auto positioning

**URL:** <https://discourse.processing.org/t/question-for-peasycam-auto-positioning/23867>\
**Category:** Libraries\
**Created:** [September 15, 2020, 9:38am UTC](https://discourse.processing.org/t/question-for-peasycam-auto-positioning/23867 "2020-09-15T09:38:56Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Chrisir](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/chrisir/32/45_2.png) [@Chrisir](https://discourse.processing.org/u/Chrisir)\
**Post date:** [September 15, 2020, 9:38am UTC](https://discourse.processing.org/t/question-for-peasycam-auto-positioning/23867/1 "2020-09-15T09:38:56Z")

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Hello all,

I have a question to Peasycam

I‘d like to zoom and pan the cam during an animation to the area where something happens. Think of an animation of a game of chess where the board is so big that the camera wanders smoothly from move to move (with lerp/easing).

I have screenX, screenY and also 3D coordinates

All help appreciated

Warm regards

Chrisir

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**Author:** ![raron](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/raron/32/13651_2.png) [@raron](https://discourse.processing.org/u/raron)\
**Post date:** [September 15, 2020, 4:08pm UTC](https://discourse.processing.org/t/question-for-peasycam-auto-positioning/23867/2 "2020-09-15T16:08:35Z")

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Hi @Chrisir

This doesn’t work, so I’m not sure how helpful it is.

There’s no available set position method (that I know), but the camera getState() and setState() methods can get and set its position, rotation etc (You probably know about this). Unfortunately, getting the position from this isn’t easy (at least I don’t know how). [https://github.com/jdf/peasycam](https://github.com/jdf/peasycam)

My thought was to make a clone (ish) of this state object, and maybe use that to set position. But no luck so far. (It’s serializable. I wonder if it’s possible to save/load from disk, but that would be a bit stupid. Haven’t tried that. But maybe some other way?).

Basically copied this: [https://github.com/jdf/peasycam/blob/master/src/peasy/CameraState.java](https://github.com/jdf/peasycam/blob/master/src/peasy/CameraState.java)  
And added some other bits to get it to run. Very hacky.

Peasycam lookAt() also reacts a bit strange.

Here’s what I got so far. Maybe some others (that actually know what they are doing 😛 ) have better ideas.

For testing. Left-click saves camera state, right-click restores it. There’s also WASD + RF (up/down). Panning (middle mouse button) seems to have disappeared.

```auto
/** PeasyCam get set position test 
*/

import peasy.*;
import peasy.org.apache.commons.math.geometry.Rotation;
//import peasy.org.apache.commons.math.geometry.RotationOrder;
import peasy.org.apache.commons.math.geometry.Vector3D;
import java.io.Serializable;

PShape shpSphere;
int moveFB, moveLR, moveUD; // used with WASD + R/F and cam.lookAt() method.

// Attempt at making a "clone" of PeasyCam's CameraState
// to set position via its Vector3D
Rotation rot = new Rotation(new Vector3D(0,0,1), new Vector3D(0,1,0)); // dummy/temp rotation
Vector3D vec3D = new Vector3D(0,0,0); // temp Vector3D
clonedCameraState myCamState = new clonedCameraState(rot, vec3D, 100);

PeasyCam cam;
CameraState savedState;

float cx, cy, cz;

void setup()
{
  size(400,400,P3D);
  avoidClipping();
 
  sphereDetail(10);
  shpSphere = createShape(SPHERE, 20);
  shpSphere.setStroke(color(0,0,128));
  shpSphere.setFill(color(0));
  
  cam = new PeasyCam(this, 0, 0, 0, 200);
  savedState = cam.getState();
}

void draw()
{ 
  background(0);

  cam.lookAt(cx, cy, cz);
  
  shape(shpSphere);

  cam.beginHUD();
  float[] cpos = cam.getPosition();

  text("Cam pos : " + cpos[0] + ", " + cpos[1] + ", " + cpos[2], 20,20);
  //text("Camera state: " + savedState, 20, 40);
  //text("myCamera state: " + myCamState, 20, 60);
  cam.endHUD();
}

void avoidClipping() {
  perspective(PI/3.0, (float) width/height, 1, 1000000);
}

void mouseClicked() {
  if (mouseButton == LEFT) {
    println();
    println("Left clicked");
    savedState = cam.getState(); 
    println(savedState);

    //myCamState = cam.getState(); // doesn't work
    //myCamState = (clonedCameraState) savedState; // doesn't work
    println(myCamState);
  }
  
  if (mouseButton == RIGHT) {
    println();
    println("Right clicked");
    println(savedState);
    cam.setState(savedState);
  }
}

void keyPressed() {
    
  if (key == 'w') moveFB = -100;
  if (key == 's') moveFB = 100;
  if (key != 'w' && key != 's') moveFB = 0;
  if (key == 'a') moveLR = -100;
  if (key == 'd') moveLR = 100;
  if (key != 'a' && key != 'd') moveLR = 0;
  if (key == 'r') moveUD = -100;
  if (key == 'f') moveUD = 100;
  if (key != 'r' && key != 'f') moveUD = 0;

  cx += moveLR;
  cy += moveUD;
  cz += moveFB;
  
  println(key);
}

void keyReleased() {
  moveLR = 0;
  moveUD = 0;
  moveFB = 0;
}

public class clonedCameraState implements Serializable {
	private static final long serialVersionUID = 1L; // Needs to be the same as PeasyCam's ID
	final Rotation rotation;
	final Vector3D center;
	final double distance;
  
  final Vector3D LOOK = Vector3D.plusK;
  final Vector3D UP = Vector3D.plusJ;

	public clonedCameraState(final Rotation rotation, final Vector3D center,
			final double distance) {
		this.rotation = rotation;
		this.center = center;
		this.distance = distance;
	}

	public void apply(final PApplet a) {
		if (a.recorder != null) {
			apply(a.recorder);
		}
		apply(a.g);
	}
	public void apply(final PGraphics g) {
		apply(g, center, rotation, distance);
	}

	void apply(final PGraphics g, final Vector3D center, final Rotation rotation,
			final double distance) {
		final Vector3D pos = rotation.applyTo(LOOK).scalarMultiply(distance).add(center);
		final Vector3D rup = rotation.applyTo(UP);
		g.camera((float)pos.getX(), (float)pos.getY(), (float)pos.getZ(), //
				(float)center.getX(), (float)center.getY(), (float)center.getZ(), //
				(float)rup.getX(), (float)rup.getY(), (float)rup.getZ());
	}

}

```

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<div class="post-metadata">

**Author:** ![Gus\_Fermin](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/gus_fermin/32/5851_2.png) [@Gus\_Fermin](https://discourse.processing.org/u/Gus_Fermin)\
**Post date:** [May 26, 2022, 4:55am UTC](https://discourse.processing.org/t/question-for-peasycam-auto-positioning/23867/3 "2022-05-26T04:55:19Z")

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Hi there…

Reading here found this other post that I think you should see, because of its relation to your post. I found it yesterday looking for a way to save the `cam.setState` so that I was able to return to that exact camera view while writing. I tried to print to the console  
`cam.setState` and I got this output, changing between keystrokes.

state1 = peasy.CameraState@127eec75  
state1 = peasy.CameraState@419b289a  
state1 = peasy.CameraState@3a64d831  
state1 = peasy.CameraState@4d23537d

Is this output what you refer to as “serialized” ? sort of like when you try to see the actual position / location? in an array… I was expecting some coordinates (x, y, z) of the position of the camera in that 3D space…  
Have not used it yet. Will install manually as I do not see it in the Contribution Manager. The states get saved to a JSON file. Excited to try it  
🙂

FPVCam by @LuisFerreira

> [@First Person View Cam (FPVCam)](https://discourse.processing.org/t/first-person-view-cam-fpvcam/22816):
>
> Hello everyone, I spent some time searching for ways or libraries to move a camera with the WASD keys but i could never find something, until now… I didn’t want to reinvent the wheel, and since Peasycam is one of the most popular camera libraries that exists, i tried to add more functionality to it, and named it First Person View Cam (FPSVCam) And it works! Most of the time… there’s still a bug with the movement when the look-at direction is almost parallel with an axis. Would someone accept t…