peter nitsch.net

Apr 25, 2007

Leveraging existing 2D code in Papervision3D

It's truly a testament to Papervision3D's ease-of-use that developers can leverage existing routines from previous 2D projects by simply modifying Movieclip references to DisplayObject3D. I put this little demo together with a set of stacked Mistubishi logos reacting to some slinky physics I built for a 2D AS2 project.

Here's an excerpt from the frame code that reproduces the slinky effect. You'll probably recognize this as a fairly conventional method of producing the same result in 2D. The only major difference are the references to Decoration3D which is just a class I built to extend DisplayObject3D.

PLAIN TEXT

Actionscript:

//Spin the stack around slowly
__rootNode.rotationY += 1;
for( var i:Number = 0; i<__bubbleArray.length; i++){
var currentBubble:Decoration3D = __bubbleArray[i]; //Decoration3D extends DisplayObject3D
if( i == 0 ){
//Case of first logo in the stack
var dx:Number = currentBubble.x - __container.mouseX;
var dy:Number = currentBubble.y - __container.mouseY;
var angle:Number = Math.atan2(dy, dx);
var targetX : Number = __container.mouseX + Math.cos(angle) * __springLengthValue;
var targetY : Number = __container.mouseY + Math.sin(angle) * __springLengthValue;
} else {
//Case of every logo following the first
var lastBubble:Decoration3D = __bubbleArray[i-1]; //Decoration3D extends DisplayObject3D
var dx:Number = currentBubble.x - lastBubble.x;
var dy:Number = currentBubble.y - lastBubble.y;
var angle:Number = Math.atan2(dy, dx);
var targetX : Number = lastBubble.x + Math.cos(angle) * __springLengthValue;
var targetY : Number = lastBubble.y + Math.sin(angle) * __springLengthValue;
}
currentBubble.vx += ( targetX - currentBubble.x ) * __springValue;
currentBubble.vy += ( targetY - currentBubble.y ) * __springValue;
currentBubble.vy += __gravityValue;
currentBubble.vx *= __frictionValue;
currentBubble.vy *= __frictionValue;
currentBubble.x += currentBubble.vx;
currentBubble.y += currentBubble.vy;
currentBubble.rotationZ = currentBubble.vx * __frictionValue;
__scene.renderCamera( __camera );
}