Tag Archives: flash

globalToLocal() in 3D

By Zevan | August 30, 2009
CLICK HERE TO COPY
Actionscript:
  1. [SWF(frameRate=60, backgroundColor=0x000000, width=500, height=500)]
  2. stage.quality = "medium";
  3. var frame:Sprite = Sprite(addChild(new Sprite()));
  4. with (frame.graphics) beginFill(0xCCCCCC), drawRect(-200, -200, 400, 400), endFill();
  5. frame.x = stage.stageWidth / 2;
  6. frame.y = stage.stageHeight / 2;
  7. frame.z = 100;
  8.  
  9. var canvas:Shape = Shape(frame.addChild(new Shape()));
  10. var msk:Shape = Shape(frame.addChild(new Shape()));
  11. with (msk.graphics) beginFill(0x00FF00), drawRect(-200, -200, 400, 400), endFill();
  12. canvas.mask = msk
  13.  
  14. var txt:TextField = TextField(addChild(new TextField()));
  15. txt.defaultTextFormat = new TextFormat("_sans", 12);
  16. txt.x = txt.y = 10;
  17. txt.textColor = 0xFFFFFF, txt.autoSize="left", txt.text = "Draw on the 3D plane...";
  18.  
  19. stage.addEventListener(MouseEvent.MOUSE_DOWN, onDown);
  20. stage.addEventListener(MouseEvent.MOUSE_UP, onUp);
  21. function onDown(evt:MouseEvent):void{
  22.     canvas.graphics.lineStyle(4, 0x000000);
  23.     var pnt:Point = frame.globalToLocal(new Point(mouseX, mouseY));
  24.     canvas.graphics.moveTo(pnt.x, pnt.y);
  25.     addEventListener(Event.ENTER_FRAME, onDraw);
  26. }
  27. function onUp(evt:MouseEvent):void{
  28.     removeEventListener(Event.ENTER_FRAME, onDraw);
  29. }
  30.  
  31. var t:Number = 0;
  32. addEventListener(Event.ENTER_FRAME, onLoop);
  33. function onLoop(evt:Event):void {
  34.     frame.rotationY = 35 * Math.sin(t);
  35.     frame.rotationX = 35 * Math.cos(t);
  36.     t+=0.02;
  37. }
  38.  
  39. function onDraw(evt:Event):void {
  40.         var pnt:Point = frame.globalToLocal(new Point(mouseX, mouseY));
  41.     canvas.graphics.lineTo(pnt.x, pnt.y);
  42. }

This demo shows that globalToLocal() works with 3D - saving us the trouble of doing some extra math if we want to draw on 3D display objects...

Have a look at the swf....


Was made aware of this trick by watching a video that kevinSuttle sent me via twitter. The video is an interview with Chris Nuuja (one of the flash player engineers).

Posted in 3D, DisplayObject, Graphics, misc, motion | Also tagged , | 3 Comments

3D Key Controls

By Zevan | August 30, 2009
CLICK HERE TO COPY
Actionscript:
  1. [SWF(backgroundColor=0x000000, width=500, height=500)]
  2. var hsw:Number = stage.stageWidth / 2;
  3. var hsh:Number = stage.stageHeight / 2;
  4. var pointNum:int = 300;
  5. var points3D:Vector.<Number> = new Vector.<Number>();
  6. var points2D:Vector.<Number> = new Vector.<Number>();
  7. var uvts:Vector.<Number> = new Vector.<Number>();
  8. var sorted:Array = [];
  9. var pnt:Point = new Point();
  10. var m:Matrix3D = new Matrix3D();
  11. var v:Vector3D = new Vector3D();
  12. for (var i:int = 0; i<pointNum; i++){
  13.     v.x = 300;
  14.     v.y = v.z = 0;
  15.     m.identity();
  16.     m.appendRotation(Math.random()*360, Vector3D.X_AXIS);
  17.     m.appendRotation(Math.random()*360, Vector3D.Y_AXIS);
  18.     m.appendRotation(Math.random()*360, Vector3D.Z_AXIS);
  19.     v = m.transformVector(v);
  20.     points3D.push(v.x, v.y, v.z);
  21.     points2D.push(0,0);
  22.     uvts.push(0,0,0);
  23.     sorted.push(new Vector3D());
  24. }
  25. points3D.fixed = true;
  26. points2D.fixed = true;
  27. uvts.fixed = true;
  28. var p:PerspectiveProjection = new PerspectiveProjection();
  29. var proj:Matrix3D = p.toMatrix3D();
  30. var rx:Number = 0, ry:Number = 0;
  31. addEventListener(Event.ENTER_FRAME, onLoop);
  32. function onLoop(evt:Event):void {
  33.     var i:int, j:int;
  34.     m.identity();
  35.     if (key[Keyboard.RIGHT]){
  36.         rx+=3
  37.     }else
  38.     if (key[Keyboard.LEFT]){
  39.         rx-=3
  40.     }else
  41.     if (key[Keyboard.UP]){
  42.         ry-=3
  43.     }else
  44.     if (key[Keyboard.DOWN]){
  45.         ry+=3
  46.     }
  47.     m.appendRotation(rx, Vector3D.Y_AXIS);
  48.     m.appendRotation(ry, Vector3D.X_AXIS);
  49.     m.appendTranslation(0, 0, 1000);
  50.     m.append(proj);
  51.     Utils3D.projectVectors(m, points3D, points2D, uvts);
  52.     for (i = 0, j = 0; i<points2D.length; i+=2, j++){
  53.         sorted[j].x = points2D[i] + hsw;
  54.         sorted[j].y = points2D[i + 1] + hsh;
  55.         sorted[j].z = uvts[j * 3 + 2];
  56.     }
  57.     sorted.sortOn("z", Array.NUMERIC);
  58.     graphics.clear();
  59.     graphics.lineStyle(2, 0x000000, 0.1);
  60.     for(i = 0; i<sorted.length; i++){
  61.         var zpos:Number = sorted[i].z * 12000;
  62.         var c:int = zpos * 14;
  63.         c = (c> 255) ? 255 : c;
  64.         graphics.beginFill(100<<16 | 100 <<8 |c);
  65.         graphics.drawCircle(sorted[i].x, sorted[i].y,zpos);
  66.         graphics.endFill();
  67.     }
  68. }
  69.  
  70. // permanently applies the matrix to the points3D vector
  71. function applyTransform():void{
  72.     m.identity();
  73.     m.appendRotation(rx, Vector3D.Y_AXIS);
  74.     m.appendRotation(ry, Vector3D.X_AXIS);
  75.     var temp:Vector.<Number> = new Vector.<Number>();
  76.     m.transformVectors(points3D, temp);
  77.     points3D = temp;
  78.     points3D.fixed = true;
  79.     rx = 0, ry = 0;
  80. }
  81.  
  82. // basic key setup
  83. var key:Object = new Object();
  84. stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyPressed);
  85. stage.addEventListener(KeyboardEvent.KEY_UP, onKeyReleased);
  86. function onKeyPressed(evt:KeyboardEvent):void {
  87.     key[evt.keyCode] = true;
  88.     key.keyCode = evt.keyCode;
  89. }
  90. function onKeyReleased(evt:KeyboardEvent):void {
  91.   applyTransform();
  92.   key[evt.keyCode] = false;
  93. }

In response to Thomas Francis's question, this snippet takes the Simple z-sorting snippet and shows how one might go about adding some basic key controls to it. It works by permanently applying x and y rotation transformations to the set of 3D points every time a key is released.

Check out the swf...

If you need to be able to rotate on both the x and y axis at the same time - and just need more flexibility... one way to do it would be to use quaternions - which may be tricky - but there are plenty of examples out there in java, processing and C/C++ just waiting to be ported (been on the todo list for some time actually).

Haven't been posting every day because I've been out of the country and away from my computer... have a backlog of snippets that need to be cleaned up and put in the pipeline...

Posted in 3D, Graphics, Vector, keys | Also tagged , | 3 Comments

Simple z-sorting

By Zevan | August 28, 2009
CLICK HERE TO COPY
Actionscript:
  1. [SWF(backgroundColor=0x444444, width=500, height=500)]
  2. var hsw:Number = stage.stageWidth / 2;
  3. var hsh:Number = stage.stageHeight / 2;
  4.  
  5. var pointNum:int = 200;
  6. var points3D:Vector.<Number> = new Vector.<Number>();
  7. var points2D:Vector.<Number> = new Vector.<Number>();
  8. var uvts:Vector.<Number> = new Vector.<Number>();
  9. var sorted:Array = [];
  10.  
  11. var pnt:Point = new Point();
  12. var m:Matrix3D = new Matrix3D();
  13. var v:Vector3D = new Vector3D();
  14. for (var i:int = 0; i<pointNum; i++){
  15.     v.x = Math.random()*400-200;
  16.     m.identity();
  17.     m.appendRotation(Math.random()*360, Vector3D.X_AXIS);
  18.     m.appendRotation(Math.random()*360, Vector3D.Y_AXIS);
  19.     m.appendRotation(Math.random()*360, Vector3D.Z_AXIS);
  20.     v = m.transformVector(v);
  21.     points3D.push(v.x, v.y, v.z);
  22.     points2D.push(0,0);
  23.     uvts.push(0,0,0);
  24.     sorted.push(new Vector3D());
  25. }
  26. points3D.fixed = true;
  27. points2D.fixed = true;
  28. uvts.fixed = true;
  29.  
  30. var p:PerspectiveProjection = new PerspectiveProjection();
  31. var proj:Matrix3D = p.toMatrix3D();
  32.  
  33. var dx:Number = 0, dy:Number = 0;
  34. addEventListener(Event.ENTER_FRAME, onLoop);
  35. function onLoop(evt:Event):void {
  36.     var i:int, j:int;
  37.     dx += (mouseX - dx) / 4;
  38.     dy += (mouseY - dy) / 4;
  39.     m.identity();
  40.     m.appendRotation(dx, Vector3D.Y_AXIS);
  41.     m.appendRotation(dy, Vector3D.X_AXIS);
  42.     m.appendTranslation(0, 0, 1000);
  43.     m.append(proj);
  44.    
  45.     Utils3D.projectVectors(m, points3D, points2D, uvts);
  46.    
  47.     for (i = 0, j = 0; i<points2D.length; i+=2, j++){
  48.         sorted[j].x = points2D[i] + hsw;
  49.         sorted[j].y = points2D[i + 1] + hsh;
  50.         sorted[j].z = uvts[j * 3 + 2];
  51.     }
  52.     sorted.sortOn("z", Array.NUMERIC);
  53.    
  54.     graphics.clear();
  55.     for(i = 0; i<sorted.length; i++){
  56.         var zpos:Number = sorted[i].z * 12000;
  57.         var c:int = zpos * 14;
  58.         graphics.beginFill(c <<16 | c <<8 | c);
  59.         graphics.drawCircle(sorted[i].x, sorted[i].y,zpos);
  60.         graphics.endFill();
  61.     }
  62. }

Here is an easy way to do z-sorting on a cluster of circles.


Have a look at the swf over at wonderfl...

Posted in 3D, Graphics, Vector, sortOn | Also tagged , | 5 Comments

BitmapData Static

By Zevan | August 24, 2009
CLICK HERE TO COPY
Actionscript:
  1. var canvas:BitmapData = new BitmapData(500,500,false, 0x000000);
  2. addChild(new Bitmap(canvas));
  3.  
  4. var pix:Vector.<uint> = new Vector.<uint>(canvas.width * canvas.height, true);
  5.  
  6. addEventListener(Event.ENTER_FRAME, onLoop);
  7. function onLoop(evt:Event):void {
  8.     canvas.lock();
  9.     var i:int = pix.length;
  10.     while(--i> -1){
  11.         var c:uint = uint(Math.random() * 255);
  12.         pix[i] = c <<16 | c <<8 | c;
  13.     }
  14.     canvas.setVector(canvas.rect, pix);
  15.     canvas.unlock();
  16. }

This is an easy way to fill a BitmapData Object up with a bunch of TV-style static....

This post is meant to serve as filler while I work to get a good solid SIMPLE fp10, drawing api z-sorting example going... There seem to be 3 main ways of doing z-sorting all of which don't seem right to me for some reason... they all work... but I have a gut feeling there is a faster way... The winner so far (unexpectedly) is using Array.sortOn

Posted in BitmapData, Vector, misc | Also tagged , | 6 Comments