Rotating a Model in Away3D - actionscript-3

Here's what i want to do:
I want to load a model (most likely .3ds) into my .swf and be able to rotate it with the mouse.
This works fine at first glance, but there's problem, the rotations 'switch' over. Or to say it differently:
Imagine we have a model in the shape of a pipe.
If we drag the mouse to the right, the model rotates along its X-Axis to the left, mouse to the left, X-Axis rotation to the right, moving the mouse up, Y-Axis rotation downward, mouse down, Y-Axis rotation upward.
Now, lets say we turn the pipe to the right or left, until we face the (former) 'backside' of the pipe, and then we move the mouse down. The model will rotate downward instead of upward.
I hope you understand what i mean with this. I've been looking around for a good while now and never found a satisfying solution. There was talk about quaternions, but i can't grasp them.
Another suggestion i read somewhere is the following:
create a Matrix3D object, apply rotation on it, then multiply it with the desired Matrix3D of my 3d-Model.
I tried to do it, but the result stays the same, the directions of rotation switches depending on what side i'm facing.
private function update(e:Event):void
{
xCalc = (0.3*(stage.mouseX - lastMouseX));
yCalc = (0.3*(stage.mouseY - lastMouseY));
if(move)
{
var objTransform:Matrix3D = new Matrix3D();
objTransform.prependRotation(xCalc, Vector3D.Y_Axis, objC.pivotPoint);
objTransform.prependRotation(yCalc, Vector3D.X_Axis, objC.pivotPoint);
mesh.transform = multiply3DMatrices(mesh.transform, objTransform);
}
lastMouseX = stage.mouseX;
lastMouseY = stage.mouseY;
view.render();
}
multiply3DMatrices simply multiplies two 4x4 Matrices together.
objC is the ObjectContainer3D that holds my model. For some reason i cannot rotate it properly, unless i manipulate the rotationX/Y/Z properties.
mesh is the mesh inside of the Model (which is very simple, a single mesh).
Also, i'm aware that i could try another Framework for this (like papervision) but this project requires me to use Away3D.

Solved it by myself, the problem was that i created a new Matrix3D Object every time. The fixed code looks like this:
private function update(e:Event):void
{
...
if(move)
{
var objTransform:Matrix3D = mesh.transform;
objTransform.appendRotation(xCalc, Vector3D.Y_Axis, objC.pivotPoint);
objTransform.appendRotation(yCalc, Vector3D.X_Axis, objC.pivotPoint);
mesh.transform = objTransform;
}
...
}
And yes, the user bwroga was actually right, i should've used appendRotation instead of prependRotation, as well.

Related

flash actionscript 3.0 hide part of an image

I am working on a flash sound mixer application with multiple sound channels, and I am having trouble with the lights beside the volume knob.
Is there a way to hide just a part of an image?
On the image below, image-2 is on top of image-1 to create some kind of volume level indicator effect, and how much of image-2 is shown depends on the value of the volume.
image-url: http://s30.postimg.org/r3ow1g5bl/volume_lights_level.png
I've tried by just reducing the height of image-2, but it looks awful and distorted.
Is there something in flash that works closely the same as CSS's behavior.
example: I'll just make image-2 a background of a shape, and when I reduce the shape's height, the image-background does not get distorted or changes it's height as well.
By searching for solutions, I have come across the mask property, but I don't quite understand how it works, and most of the examples shown are images placed inside circles.
Is the mask property applicable in this situation?
I'm quite new to flash so I don't know a lot of things yet.
You can indeed use a mask.
How to programmatically create your mask
Put an occurrence of your image named myImage on the stage, and put over this occurrence a mask named myMask with the same dimensions. You can apply myMask mask to myImage using it's mask property like below:
Main Timeline
myImage.mask = myMask;
function mouseMoveHandler(e:MouseEvent):void {
myMask.height = myImage.y - e.stageY;
}
stage.addEventListener(MouseEvent.MOUSE_MOVE, mouseMoveHandler);
You have just to adapt this code to your animation, in the function where you click your button.
I got it working now, many THANKS #VC.One. heres how I did it.
Imported img-2 to stage, converted it into symbol(type:Movie Clip), assigned instance name: img2_mc.
I created a new layer for the mask, drawn a rectangle using rectangle tool, converted it also to symbol(type:Movie Clip), assigned instance name: mask_mc.
Then applied the mask to img2_mc.
/* the code */
img2_mc.mask = mask_mc;
function onEnterFrame(event:Event):void{
var volumeKnob_y = volSliderKnobOn.y + 12; // adjust it to the center of the knob
mask_mc.height = volumeKnob_y;
}

Flash Games: Make a world continuous, circular

I am writing now a flash game and I run into a an issue. I have a map for the game which is defined as a 2-D array, where each element represents a component of the map. The player is always in the center of the map.
The problem is when the player reaches one end of the map. Now it is empty space. I want that the player instead of seeing the empty space, to see another end of the map and in this way, the map will loo like it goes around.
So for example if the player goes to right he will eventually start seeing the the left side of the map and the world will look continuous.
Does anyone knows how to implement this functionality?
You could make the array 2 times and put the first one behind the second one again and than the second one behind the first etc etc..
It's done here with 2 pictures, just use the arrays instead:
//The speed of the scroll movement.
var scrollSpeed:uint = 2;
//This adds two instances of the movie clip onto the stage.
var s1:ScrollBg = new ScrollBg();
var s2:ScrollBg = new ScrollBg();
addChild(s1);
addChild(s2);
//This positions the second movieclip next to the first one.
s1.x = 0;
s2.x = s1.width;
//Adds an event listener to the stage.
stage.addEventListener(Event.ENTER_FRAME, moveScroll);
//This function moves both the images to left. If the first and second
//images goes pass the left stage boundary then it gets moved to
//the other side of the stage.
function moveScroll(e:Event):void{
s1.x -= scrollSpeed;
s2.x -= scrollSpeed;
if(s1.x < -s1.width){
s1.x = s1.width;
}else if(s2.x < -s2.width){
s2.x = s2.width;
}
}
You simply check if your player is about to get off the "right" or "left" edge of the map, and position him at the other edge. To draw a circular map, you can use the following technique: if you are about to draw a column of a number that exceeds the map's width, decrease that number by width and draw the column at resultant index; and if you are about to draw a column at index below zero, add width and draw the column at resultant index. If you are in troubles of making a hitcheck at continuous map's borders, you can employ the same trick to find neighbors. (The "circular array" is a pretty basic algorithmic problem, and is resolved in many ways already)
You have a few options here. You can do the pac-man style of just making your character pop up on the other side of the screen, but that would require you to abandon the cool bit of the character being in the middle at all times.
On to the real suggestions:
If you're not implementing your array as one solid object (i.e. making it draw individual collumns/rows at a time) then this is a no-brainer. Just have a function that returns the index of the next collumn/row, within certain bounds. Like, if your array is 40 elements wide, when it tries to draw element 41, subtract the size of the array, and make it draw element 1 instead.
If your array is one solid object (like if you drew it onto a stage object and are just manipulating that) and it's not very big, you could probably get away with drawing a total of four of them, and just having a new one cover up any whitespace that's about to appear. Like, as you approach the right edge of the first array, the second array moves to the right of it for a lawless transition.
If your array is a solid object and is very big, perhaps you could make eight buffer objects (one per edge and one per corner) that hold approximately half a screen's worth of the array. That way as you approach the right edge, you see the left edge, but then when you cross into the buffer zone, you could teleport the player to the corresponding position on the left of the array, which has the buffer for the right size. To the player, nothing has changed, but now they're on the other side of the world.

localToGlobal/globalToLocal AS3 confusion

I want to move a display object from one container to another, but have it appear in the same place on screen.
I thought I'd understood this years ago, but the following does not work:
function moveToNewContainer(obj:DisplayObject, newParent:DisplayObjectContainer):void {
var pos:Point = new Point(obj.x, obj.y);
var currentParent:DisplayObjectContainer = obj.parent;
pos = currentParent.localToGlobal(pos);
currentParent.removeChild(obj);
newParent.addChild(obj);
pos = newParent.globalToLocal(pos);
obj.x = pos.x;
obj.y = pos.y;
}
This doesn't position the object in the same place as I would have expected.
Does anyone know what I am doing wrong, please?
Thanks,
James
Using localToGlobal/globalToLocal and setting the x and y properties like you showed calculates the correct position for the object in its new parent, but does not adjust for other aspects of the transformation such as scaling or rotation. In other words, the object's registration point will indeed remain in the same place, but the object may be rotated, scaled, or sheared differently.
The solution to your problem will need to take into account the transform.concatenatedMatrix properties of the old and new parents--you'll need to multiply the object's transformation matrix by one and then by the inverse of the other, or something along those lines. Leave a comment if you need help working out the math.
There is nothing wrong with your code, provided that both containers have no transformations applied. If your clips are scaled, rotated, etc.. you need to handle that in addition to the coordinate space transformations that localToGlobal and globalToLocal do.
You have to check if your containers are actually placed on stage. If your new container isn't added as a child to stage, function globalToLocal fails, just because it doesnt know how to correctly calculate that data.

Why does this ActionScript Flip cause a blur on my website?

I'm using a flip mechanism to navigate through my site (flip file & demo). The problem is, once it's flipped the content been displayed good just like I want it, but there's some offset from the flipped (right) parts en the solid left part (visible when you look closely). Also the right part is now a little blurred (which is the disturbing part of my issue). This all caused by the flip (I think the rotationY is causing the problem).
When I click a button I do the following:
flip=new Flip(currentPage,nextPage,richting);
content.addChild(flip);
currentPage=nextPage;
nextPage = new MovieClip();
there is a fix for it, consider the following:
// store original matrix
var origMatrix:Matrix = box.transform.matrix;
// set initial position
box.rotationY = -180;
// start animation
TweenLite.to(box, 1, {rotationY:0, onComplete:cleanBlur})
// execute after animation complete
function cleanBlur():void {
box.transform.matrix = origMatrix;
}
maybe you can find better results using other 3d library.
EDIT: sorry the "box" object, I was testing in flash, but box would be any of your pages to flip. Just apply the same logic.
Matteo at Flash & Math has an excellent solution for this. He actually found that when you bring an object into native 3D space it expands the object by one pixel in both the width and height. This can be counteracted by scaling your object back and then setting it's z to 0 which will scale it back up. Now the object is ready to play with without the blur.
http://www.flashandmath.com/flashcs4/blursol/index.html
adding: This fixes the scale issue, but not the blurriness. You will still need to use the matrix transformation fix posted above.

Deleting a shape via code

Pretty basic question here, but its still got me a little confused..
I have an object(navigation menu bar) that I want to change the colors on with code, so in an updateColor function, I get the bounds of the object (which is a drawing shape contained in a movieclip) and redraw a new shape on top of it with the new color, but I've noticed that the last shape still exists behind this redraw.
I tried using obj.graphics.clear(); before the redraw but that didn't get rid of the original shape. Is there another command that I'm overlooking?
Unless you drew the object you wish to remove within the same graphics object, clearing won't work. You need to remove the DisplayObject.
Depending on the number of children you can do:
obj.removeChildAt(0);
This also removes movieclips / buttons you placed on the stage manually.
If you have a reference to the DisplayObject you wish to remove you can simply do
obj.removeChild(backgroundClip);
Note that you can also change the color of a DisplayObject directly:
import flash.geom.ColorTransform;
...
public var test:MovieClip; //instance on stage
...
var cf:ColorTransform = test.transform.colorTransform;
cf.color = 0xff0000;
test.transform.colorTransform = cf;
while(this.numChildren)
{
this.removeChildAt(0);
}
Will clear child object on this MovieClip,
if it's clearing too much, then put the shape drawing in a subclip, and clear the subclip.