i want to rotate 3D an Image called img1 in Flex. I want to rotate it around y axis 180 degree. I can do this by using 3D effect already built in Flex but i want to do a bit more different.
I want during rotating, there's another image called img2 appear on back of img1 (in default case, the image appear on the back is img1) and when rotating finish, the image will be img2.
How can i do this ?
Thank you.
If you need no perspective effect, it's quite easy to do. A rough implementation (not tested!):
// Event.ENTER_FRAME event listener
void on_enter_frame(event:Event):void
{
// m_angle is a member of the class/flex component where on_enter_frame is declared
// ANGLE_DELTA is just a constant
m_angle += ANGLE_DELTA;
// Angle clamping to the range [0, PI * 2)
m_angle %= Math.PI * 2;
if (m_angle < 0)
m_angle += Math.PI * 2;
// If we currently look at the front side...
if (m_angle < Math.PI)
{
img1.visible = true;
img2.visible = false;
img1.scaleX = Math.cos(m_angle);
}
else
{
img1.visible = false;
img2.visible = true;
// If you omit negation, the back-side image will be mirrored
img2.scaleX = -Math.cos(m_angle);
}
}
So every frame we increase the rotation angle, clamp it to the range [0, PI * 2). Then depending on the value of the rotation angle, we hide/show the pair of your images, and then perform x-scaling of the visible image.
Thank you, now i found a solution. Please check it here, it's very easy to do.
http://forums.adobe.com/thread/921258
Related
Three.js 76
I start to use Orthographic camera instead Perspective - has some troubles.
I use stemkoski's shader-glow for point animation in scene: he created some sphere and then use shader for it transparancy, i just add animation to it.
function animatePoints() {
var alphas;
var count;
var time;
let j = 0;
while ( animatedPoints[j] ) {
let threeGlow = animatedPoints[j];
let finishAnimation = threeGlow.meta.state.finishAnimation;
let itFinished = 0;
let pointGlowMat = threeGlow.material;
let pointGlowGeom = threeGlow.geometry;
// ########## make glow look at camera
pointGlowMat.uniforms.viewVector.value = new THREE.Vector3().subVectors( threeGlow.position, camera.position);
alphas = pointGlowGeom.attributes.alpha;
count = alphas.count;
time = 0.001* Date.now();
if ( finishAnimation ) {
....
} else {
....
}
alphas.needsUpdate = true;
j++;
}
}
Main goal - to make glow look at camera. When camera was perspective i use solution with subtracts two vectors - camera position and glow position, so it look like glow looking at camera.
pointGlowMat.uniforms.viewVector.value = new THREE.Vector3().subVectors( camera.position, threeGlow.position );
But now, when i use Orthographic camera this solution doesn't work correctly.
The problem is that now the glow should look not at camera position point, it should look at plane of the camera.
I make some pic scheme for that situation:look it, it very useful
So for each new glow (it's positions of course different) i must get new red vector, to make each glow look at orto cam.
Any ideas?
What you need to do to get the red vector in your image, is project vector sub on the vector representing the direction in which the camera is looking.
I think this is what you need:
pointGlowMat.uniforms.viewVector.value = new THREE.Vector3()
.subVectors( camera.position, threeGlow.position )
.projectOnVector( camera.getWorldDirection() );
One way to make an object "look at" an orthographic camera by using this pattern:
object.quaternion.copy( camera.quaternion );
The object's view direction will be perpendicular to the camera's projection plane.
This approach is appropriate if neither the object nor the camera have a rotated parent.
three.js r.84
Looking to animate the below SVG, which I have got working initially. However, I want it to 'draw' the second SVG in the opposite direction, WITH the dots i've defined.
Is there any way I can do this? Effectively drawing my shape from left to right with the dots.
Codepen: http://codepen.io/anon/pen/gFcAz
The normal dash offset animation trick really only works with solid lines.
This is the closest I managed to get using CSS animations.
http://jsfiddle.net/L4zCY/
Unfortunately the dashes crawl because you have no control over the step rate of the stroke-dashoffset. If you could make it step by 10 at a time, the dashes wouldn't move.
So I think the only way around it is to use Javascript.
var path = document.querySelectorAll("svg path").item(0);
animateDashedPath(path);
/*
* Animates the given path element.
* Assumes the path has a "5 5" dash array.
*/
function animateDashedPath(path)
{
var pathLength = path.getTotalLength();
var animationDuration = 2000;
var numSteps = Math.round(pathLength / (5+5) + 1);
var stepDuration = animationDuration / numSteps;
// Build the dash array so we don't have to do it manually
var dasharray = [];
while (numSteps-- > 0) {
dasharray.push(5);
dasharray.push(5);
}
dasharray.push(pathLength);
// Animation start conditions
path.setAttribute("stroke-dasharray", dasharray.join(" "));
path.setAttribute("stroke-dashoffset", -pathLength);
// We use an interval timer to do each step of the animation
var interval = setInterval(dashanim, stepDuration);
function dashanim() {
pathLength -= (5+5);
path.setAttribute("stroke-dashoffset", -pathLength);
if (pathLength <= 0) {
clearInterval(interval);
}
}
}
Demo here
Update
It looks like there is an issue with in FF. If you create the "right" number of dashes for the path length, it doesn't quite reach the end of the path. You need to add extra.
A version of the demo that works properly on FF is here
I have an sphere with divs using CSS3DRenderer. When I click to one of the divs I'd like to position/rotate the camera so the element displays in the center of the screen.
I've tried several examples and I've read other answers but still I cant get it to work.
At the moment it moves the camera but the sphere gets repositioned in different places
What I'm trying to do is the following:
Gets the HTML element's class. Then loop through an array of THREE.CSS3DObject to get its position, then use that to position the camera.
function moveCamera(element) {
for ( var i = 0; i < objects.length; i ++ ) {
var object = objects[ i ];
if(object.element.className == element.className) {
position = object.position;
rotation = object.rotation;
found = true;
break;
}
}
if (found) {
camera.rotation = rotation;
render();
found = false;
} }
What I'm I doing wrong?
Here's the example http://jsfiddle.net/37R22/1/
Thanks
You were close. You just have to move the camera to the right place.
camera.rotation.copy( rotation );
camera.position.copy( position ).multiplyScalar( 4 );
Updated fiddles: http://jsfiddle.net/37R22/2/ or http://jsfiddle.net/37R22/3/
Be careful about going behind-the-back of TrackballControls and modifying the camera properties yourself. This appears to work, however.
three.js r.65
In a drag+drop situation using Flex, I am trying to get the object center aligned to the point of drop- somehow, irrespective of the adjustments to height and width, it is always positioning drop point to left top.
here is the code..
imageX = SkinnableContainer(event.currentTarget).mouseX;
imageY = SkinnableContainer(event.currentTarget).mouseY;
// Error checks if imageX/imageY dont satisfy certain conditions- move to a default position
// img.width and img.height are both defined and traced to be 10- idea to center image to drop point
Image(event.dragInitiator).x = imageX-(img.width)/2;
Image(event.dragInitiator).y = imageY-(img.height)/2
The last 2 lines don't seem to have any effect. Any ideas why-must be something straightforward, that I am missing...
You can use the following snippet:
private function on_drag_start(event:MouseEvent):void
{
var drag_source:DragSource = new DragSource();
var drag_initiator:UIComponent = event.currentTarget as UIComponent;
var thumbnail:Image = new Image();
// Thumbnail initialization code goes here
var offset:Point = this.localToGlobal(new Point(0, 0));
offset.x -= event.stageX;
offset.y -= event.stageY;
DragManager.doDrag(drag_initiator, drag_source, event, thumbnail, offset.x + thumbnail.width / 2, offset.y + thumbnail.height / 2, 1.0);
}
Here is one important detail. The snippet uses stage coordinate system.
If you use event.localX and event.localY, this approach will fail in some cases. For example, you click-and-drag a movie clip. If you use localX and localY instead of stage coordinates, localX and localY will define coordinates in currently clicked part of the movie clip, not in the whole movie clip.
Use the xOffset and yOffset properties in the doDrag method of DragManager.
Look here for an example.
Ok, so I've been trying to get this concept to work for the day now and have had zero luck. I am not so good with math, so any help will be appreciated. I am trying to rotate a centered container from it's center. The problem with this code is when I use the rotatePicture method, it doesn't rotate from the center, instead it rotates from the box's top-left corner. Here's the code...
import mx.effects.Rotate;
private function init():void
{
calculateCoordinates();
}
private function rotateBox():void
{
var m:Matrix = myBox.transform.matrix;
var centerX:Number = myBox.width / 2;
var centerY:Number = myBox.height / 2;
var centerPoint:Point = new Point(centerX, centerY);
var transformPoint:Point= m.transformPoint(centerPoint);
m.translate(-transformPoint.x, -transformPoint.y);
m.rotate(90 * Math.PI / 180);
m.translate(transformPoint.x, transformPoint.y);
myBox.transform.matrix = m;
this.callLater(calculateCoordinates);
//calculateCoordinates();
}
private function calculateCoordinates():void
{
var x : Number = (myBox.parent.width - myBox.width) / 2;
x = x < 0 ? 0 : x;
var y : Number = (myBox.parent.height - myBox.height) / 2;
y = y < 0 ? 0 : y;
myBox.move(x, y);
}
Ok, this was a bit tricky and i'm working out a couple of details, but in case anyone had a similar issue, I found the general answer. Just took a movie break to refresh the brain...
I had to place a variable for how many turns the canvas had rotated which was easy since I was restricting the degrees to only 90. Then I place in a switch statement that tested the turns variable and recalculated the (x,y) coordinates based off of the turns. Since I knew that the Rotate class would create a cooler effect and end with the same result, I ended up using that instead.
Cheers!
I don't know what your background is, but in my experience this is a classic case of "out-thinking yourself".
You've written quite a bit of code to do something that is actually native to the Flash display API's.
Since you seem to be using Flex I'll just tell you that the simple way to achieve this is to dynamically reposition your display clip contents so that the center of your contents is at the 0,0 point of your clip.
This gets harder the more content you have, but if you just have something like an image or a button or what have you, it's really easy to just calculate the height and width, then divide by 2 and subtract.
Then the rotation property will work just fine.
In Flash it's even easier because you can just make a new clip, bind your class to the clip, and place all yours contents in the Flash authoring tool positioned properly for rotation to work as expected.
Yeah, what Back2Dos said.
Personally, I'd wrap the container in another sprite, position it so its center is at (0,0) in that sprites coordinate space, and then just rotate the sprite ... it's simple and robust ...
I'd like to use <s:Rotate> to rotate center. Hope useful to you.