1 reply to this topic

[Stimpy83]

Hi,

i'm having a really big problem to understand the pointAt function from stage3d. I think that pointAt does the same like lookAt in OpenGL - But i don't get it right.

Target:

I need a simple Camera with a target, like a target camera in 3D Max or Blender... something like this:


And my Code is - So i understand the function:

[source lang="java"]view.identity();target.x = position.x;target.y = position.y;target.z = 0;view.appendTranslation( -position.x, -position.y, -position.z);view.pointAt( target, at, up); view.invert();// at = 0,1,0// up = 0,0,1// Because Z is my UpVector[/source]

So - When i move the camera i don't have a target camera - my map rotates and fly away I really don't understand the parameters for pointAt - Can somebody explain me how pointAt works? The Adobe Docu don't say many....

Big Thanks and sry for my bad english

[DLabz]

[source lang="jscript"]package{ import flash.display.Graphics; import flash.display.Sprite; import flash.events.Event; import flash.geom.Matrix3D; import flash.geom.Point; import flash.geom.Vector3D; /** * ... * @author Petrovic Veljko <designlabz@gmail.com> */ public class Main extends Sprite { public var target:Sprite = new Sprite(); public var cam:Matrix3D = new Matrix3D(); public var view:Sprite = new Sprite(); public function Main():void { var g:Graphics; //draw top face var up:Sprite = new Sprite(); g = up.graphics; g.beginFill(0x7878FF,.5); g.drawRect( -200, -200, 400, 400); //draw bottom face var dn:Sprite = new Sprite(); g = dn.graphics; g.beginFill(0xFF00FF,.8); g.drawRect( -200, -200, 400, 400); g.endFill(); //draw arrow pointing up on screen (Y-) g.lineStyle(2); g.moveTo(-200, 0); g.lineTo(0, 200); g.lineTo(200, 0); //draw axes g = view.graphics; // X g.lineStyle(2, 0xff0000); g.moveTo(-500, -1000); g.lineTo( -500, 1000); g.moveTo(0, -1000); g.lineTo(0, 1000); g.moveTo(500, -1000); g.lineTo( 500, 1000); // Y g.lineStyle(2, 0x00FF00); g.moveTo( -1000, -500); g.lineTo(1000, -500); g.moveTo( -1000, 0); g.lineTo(1000, 0); g.moveTo( -1000, 500); g.lineTo(1000, 500); //add faces to 3D object dn.z = -200; target.addChild(dn); up.z = 200; target.addChild(up); //add object to view view.addChild(target); if (stage) init(); else addEventListener(Event.ADDED_TO_STAGE, init); } private function init(e:Event = null):void { removeEventListener(Event.ADDED_TO_STAGE, init); addEventListener(Event.ENTER_FRAME, tock); //activate 3D mode on view view.transform.matrix3D = new Matrix3D(); view.transform.matrix3D.identity(); //add view to stage addChild(view); } private function tock(e:Event = null):void { //get mouse offset from the center var o:Point = new Point(); o.x = (stage.stageWidth / 2 - mouseX); o.y = (stage.stageHeight / 2 - mouseY); //move cam cam.position = new Vector3D(5* -o.x, 5* o.y, 1000); cam.pointAt( new Vector3D( 0, 0, 0), //point in world space to look at Vector3D.Z_AXIS, //side of 3D objec facing up in world space Vector3D.Y_AXIS //where should our arrow point ); //reset view view.transform.matrix3D.identity(); //cam view.transform.matrix3D.append(cam); view.transform.matrix3D.invert(); //center view view.transform.matrix3D.appendTranslation(stage.stageWidth / 2, stage.stageHeight / 2, 1); } }}[/source]

Edited by DLabz, 08 October 2012 - 03:06 PM.