Away3D Forum RESOLVED: Camera view vector

Sorceror, Newbie
Posted: 22 September 2011 10:39 AM Total Posts: 3

I would like to have directional light on current camera position and with direction of current camera view vector. But I didn’t found any way how to obtain camera view vector of Away3D/Stage3D camera.
Is it possible to get direction or point on which is current camera looking to?
Thanks for any advice
Paul

John Brookes, Moderator
Posted: 22 September 2011 10:49 AM Total Posts: 732 [ # 1 ]

import away3d.core.math.Matrix3DUtils;
//renderloop
light.direction = Matrix3DUtils.getForward(view.camera);

Alejandro Santander, Administrator
Posted: 22 September 2011 03:35 PM Total Posts: 414 [ # 2 ]

Nice one John!

Sometimes I do this, light.transform = view.camera.transform.clone()
But yours I like more =)

Alex Bogartz, Sr. Member
Posted: 22 September 2011 04:14 PM Total Posts: 216 [ # 3 ]

Ok, I know this is probably an easy answer, but how do I get the opposite?

I can set the light to the left of the camera like so:

mainLight.direction = Matrix3DUtils.getRight(view.camera.transform);

But for “getLeft” (which doesn’t exist), I need to have the negative value of the vector. What’s the way to get that?

Choons, Sr. Member
Posted: 22 September 2011 04:27 PM Total Posts: 281 [ # 4 ]

doesn’t just changing the sign of each component reverse the vector direction?

80prozent, Sr. Member
Posted: 22 September 2011 04:29 PM Total Posts: 430 [ # 5 ]

since its a vector3d that is returned by the getRight method, you can use vector3d.negate(). never tried it, but in the adobe docs they say:

negate():void
Sets the current Vector3D object to its inverse.

Signature

sorry…i hope my actionscript is better than my english…

Alex Bogartz, Sr. Member
Posted: 22 September 2011 04:34 PM Total Posts: 216 [ # 6 ]

mainLight.direction = Matrix3DUtils.getRight(view.camera.transform);
mainLight.direction.negate();

Still makes the light appear from the left of the scene. That second line appears to have no effect.

John Brookes, Moderator
Posted: 22 September 2011 04:42 PM Total Posts: 732 [ # 7 ]

var dir:Vector3D = Matrix3DUtils.getRight(view.camera.transform);
dir.negate();
light.direction = dir;

Alex Bogartz, Sr. Member
Posted: 22 September 2011 04:55 PM Total Posts: 216 [ # 8 ]

Works!

Ok, so I think the reason the previous code didn’t work is that the setter for “direction” is like this:

public function set direction(value : Vector3D) : void
  {
   _direction = value;
   //lookAt(new Vector3D(x + _direction.x, y + _direction.y, z + _direction.z));
   if(!_tmpLookAt) _tmpLookAt = new Vector3D();
   _tmpLookAt.x = x + _direction.x;
   _tmpLookAt.y = y + _direction.y;
   _tmpLookAt.z = z + _direction.z;
   
   lookAt(_tmpLookAt);
  } 

It’s actually calling the lookAt for the light vector. And since lookAt isn’t a public function, you can’t call that on your own. Maybe it needs an applyDirection function so you could say:

light.direction.x*=1;
light.applyDirection(); 

For animating effects?

Sorceror, Newbie
Posted: 22 September 2011 07:27 PM Total Posts: 3 [ # 9 ]

Thanks a lot for all answers, this code works pretty well


light.direction = Matrix3DUtils.getForward(view.camera.viewProjection);

Paul

Alejandro Santander, Administrator
Posted: 22 September 2011 08:46 PM Total Posts: 414 [ # 10 ]

Lads, I added getters for forwardVector, rightVector, upVector, backVector,
leftVector and downVector in Object3D.as using the methods you suggested here. Everyone faces this problem often, so I figured it could be handy.

Please sync to the latest github source. You can do things like:

var director:Vector3D = cube.downVector;
director.scaleBy(500);
sphere.position = cube.position.add(director); 

RESOLVED: Camera view vector Software: Away3D 4.x

Sorceror, Newbie Posted: 22 September 2011 10:39 AM Total Posts: 3 I would like to have directional light on current camera position and with direction of current camera view vector. But I didn’t found any way how to obtain camera view vector of Away3D/Stage3D camera. Is it possible to get direction or point on which is current camera looking to? Thanks for any advice Paul
John Brookes, Moderator Posted: 22 September 2011 10:49 AM Total Posts: 732 [ # 1 ] import away3d.core.math.Matrix3DUtils; //renderloop light.direction = Matrix3DUtils.getForward(view.camera);
Alejandro Santander, Administrator Posted: 22 September 2011 03:35 PM Total Posts: 414 [ # 2 ] Nice one John! Sometimes I do this, light.transform = view.camera.transform.clone() But yours I like more =)
Alex Bogartz, Sr. Member Posted: 22 September 2011 04:14 PM Total Posts: 216 [ # 3 ] Ok, I know this is probably an easy answer, but how do I get the opposite? I can set the light to the left of the camera like so: mainLight.direction = Matrix3DUtils.getRight(view.camera.transform); But for “getLeft” (which doesn’t exist), I need to have the negative value of the vector. What’s the way to get that?
Choons, Sr. Member Posted: 22 September 2011 04:27 PM Total Posts: 281 [ # 4 ] doesn’t just changing the sign of each component reverse the vector direction?
80prozent, Sr. Member Posted: 22 September 2011 04:29 PM Total Posts: 430 [ # 5 ] since its a vector3d that is returned by the getRight method, you can use vector3d.negate(). never tried it, but in the adobe docs they say: negate():void Sets the current Vector3D object to its inverse. Signature sorry…i hope my actionscript is better than my english…
Alex Bogartz, Sr. Member Posted: 22 September 2011 04:34 PM Total Posts: 216 [ # 6 ] mainLight.direction = Matrix3DUtils.getRight(view.camera.transform); mainLight.direction.negate(); Still makes the light appear from the left of the scene. That second line appears to have no effect.
John Brookes, Moderator Posted: 22 September 2011 04:42 PM Total Posts: 732 [ # 7 ] var dir:Vector3D = Matrix3DUtils.getRight(view.camera.transform); dir.negate(); light.direction = dir;
Alex Bogartz, Sr. Member Posted: 22 September 2011 04:55 PM Total Posts: 216 [ # 8 ] Works! Ok, so I think the reason the previous code didn’t work is that the setter for “direction” is like this: `public function set direction(value : Vector3D) : void { _direction = value; //lookAt(new Vector3D(x + _direction.x, y + _direction.y, z + _direction.z)); if(!_tmpLookAt) _tmpLookAt = new Vector3D(); _tmpLookAt.x = x + _direction.x; _tmpLookAt.y = y + _direction.y; _tmpLookAt.z = z + _direction.z; lookAt(_tmpLookAt); }` It’s actually calling the lookAt for the light vector. And since lookAt isn’t a public function, you can’t call that on your own. Maybe it needs an applyDirection function so you could say: `light.direction.x*=1; light.applyDirection();` For animating effects?
Sorceror, Newbie Posted: 22 September 2011 07:27 PM Total Posts: 3 [ # 9 ] Thanks a lot for all answers, this code works pretty well `light.direction = Matrix3DUtils.getForward(view.camera.viewProjection);` Paul
Alejandro Santander, Administrator Posted: 22 September 2011 08:46 PM Total Posts: 414 [ # 10 ] Lads, I added getters for forwardVector, rightVector, upVector, backVector, leftVector and downVector in Object3D.as using the methods you suggested here. Everyone faces this problem often, so I figured it could be handy. Please sync to the latest github source. You can do things like: `var director:Vector3D = cube.downVector; director.scaleBy(500); sphere.position = cube.position.add(director);`

RESOLVED: Camera view vector

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