Libgdx Animation using images from TextureAtlas gets incorrectly rotated - animation

In my TextureAtlas the Sprite's for my Animation are rotated 90 degrees.
When I draw my Animation it's still rotaed by 90 degrees. How can I fix that?
My code looks like that:
TextureAtlas spritesheet = new TextureAtlas(Gdx.files.internal("images/spritesheet/spritesheet.atlas"));
Array<AtlasRegion> CLOUD_ANIMATION_REGIONS = spritesheet.findRegions("cloud_animation");
Animation animation = new Animation(0.1f,ImageProvider.CLOUD_ANIMATION_REGIONS);
In the render method:
batch.draw(animation.getKeyFrame(elapsedTime, true), x, y);
The animation works perfectly fien but it's rotated by 90 degree like in the spritesheet.
I realize that if I have a Sprite I can call Sprite.draw(batch) and it will fix the rotation but I don't seem to be able to use that mechanism for Animation's?
EDIT:
Like Alexander said, this will do the trick:
batch.draw(textureRegion, x, y, 0, 0,textureRegion.getRegionWidth(), textureRegion.getRegionHeight(), 1, 1, 90);

Ok, here is untested code:
TextureRegion textureRegion = animation.getKeyFrame(elapsedTime, true);
if (textureRegion instanceof TextureAtlas.AtlasRegion && ((TextureAtlas.AtlasRegion) textureRegion).rotate)
{
batch.draw(textureRegion, x, y, 0, 0, textureRegion.getRegionWidth(), textureRegion.getRegionHeight(), 1, 1, 90, true);
}
else
{
batch.draw(textureRegion, x, y);
}
What I'm doing here: I check if atlas packer marked the region as rotated and then draw it rotated 90 angle clockwise to compensate original 90 angle counter-clockwise rotation. See AtlasRegion's javadoc and special version of draw method that can rotate TextureRegion.
EDITED: fix arguments based on Markus comment

Somehow you should be using AtlasSprite I think. That carries out the unrotate in its constructor. You dont want to be rotating every frame - thats some overhead. Also the AtlasSprite should take care of trimmed regions in the atlas : something thats very important to maximise a single atlas texture. Alas it doesnt seem very easy to use as it seems one needs a seperate sprite for each frame which seems massive overhead.

Related

Three.js: change the pivot point of a sprite

I've created a 3D map and I'm labelling points on this map through Sprites. This in itself works fine, except for the positioning of the sprite labels.
Because I'm creating a map the camera can tilt from 0 to 90 degrees, while ideally the label always stays some distance directly above the item it is labelling on the screen. But unfortunately, as sprites are always centred around their origin and that overlaps the item, I have to move the sprite up on the Y world axis and with that the centre location of the sprite changes as the camera is tilted. This looks weird if the item looked at is off centre, and doesn't work too well when the camera is looking straight down.
No jsfiddle handy, but my application at http://leeft.eu/starcitizen/ should give a good impression of what it looks like.
The code of THREE.SpritePlugin suggests to me it should be possible to use "matrixWorld" to shift the sprite some distance up on the screen's Y axis while rendering, but I can't work out how to use that, nor am I entirely sure that's what I need to use in the first place.
Is it possible to shift the sprites up on the screen while rendering, or perhaps change their origin? Or is there maybe some other way I can achieve the same effect?
Three.js r.67
As suggested by WestLangley, I've created a workable solution by changing the sprite position based on the viewing angle though it took me hours to work out the few lines of code needed to get the math working. I've updated my application too, so see that for a live demo.
With the tilt angle phi and the heading angle theta as computed from the camera in OrbitControls.js the following code computes a sprite offset that does exactly what I want it to:
// Given:
// phi = tilt; 0 = top down view, 1.48 = 85 degrees (almost head on)
// theta = heading; 0 = north, < 0 looking east, > 0 looking west
// Compute an "opposite" angle; note the 'YXZ' axis order is important
var euler = new THREE.Euler( phi + Math.PI / 2, theta, 0, 'YXZ' );
// Labels are positioned 5.5 units up the Y axis relative to its parent
var spriteOffset = new THREE.Vector3( 0, -5.5, 0 );
// Rotate the offset vector to be opposite to the camera
spriteOffset.applyMatrix4( new THREE.Matrix4().makeRotationFromEuler( euler ) );
scene.traverse( function ( object ) {
if ( ( object instanceof THREE.Sprite ) && object.userData.isLabel ) {
object.position.copy( spriteOffset );
}
} );
Note for anyone using this code: that the sprite labels are children of the object group they're referring to, and this only sets a local offset from that parent object.
I had a similar problem, but with flat sprites; I put trees on a map and wanted them to rotate in such a way that they'd rotate around their base, rather than their center. To do that, i simply edited the image files of the trees to be twice as tall, with the bottom as just a transparency:
http://imgur.com/ogFxyFw
if you turn the first image into a sprite, it'll rotate around the tree's center when the camera rotates. The second tree will rotate around it's base when the camera rotates.
For your application, if you resize the textbox in such a way that the center of it would be coincide with the star; perhaps by adding a few newlines or editing the height of the sprite
This is very much a hack, but if you will only use sprites in this way, and could tolerate a global change to how sprites were rendered, you could change the following line in the compiled three.js script:
Find (ctrl+F) THREE.SpritePlugin = function, and you'll see:
this.init = function ( renderer ) {
_gl = renderer.context;
_renderer = renderer;
vertices = new Float32Array( [
- 0.5, - 0.5, 0, 0,
0.5, - 0.5, 1, 0,
0.5, 0.5, 1, 1,
- 0.5, 0.5, 0, 1
] );
I changed the definition of the array to the following:
var vertices = new Float32Array( [
- 0.5, - 0.0, 0, 0,
0.5, - 0.0, 1, 0,
0.5, 1.0, 1, 1,
- 0.5, 1.0, 0, 1
] );
And now all my sprites render with the rotation origin at the bottom.
If you use the minified version, search for THREE.SpritePlugin=function and move the cursor right until you find the Float32Array defined, and make the same changes there.
Note: this changes how things render only when using WebGL. For the canvas renderer you'll have to play a function called renderSprite() in the THREE.CanvasRenderer. I suspect playing with these lines will do it:
var dist = 0.5 * Math.sqrt( scaleX * scaleX + scaleY * scaleY ); // allow for rotated sprite
_elemBox.min.set( v1.x - dist, v1.y - dist );
_elemBox.max.set( v1.x + dist, v1.y + dist );
This function will also be a lot more difficult to find in the minified version, since renderSprite() is not an outward facing function, it'll likely be renamed to something obscure and small.
Note 2: I did try making these modifications with "polyfills" (or rather, redefining the SpritePlugin after Three is defined), but it caused major problems with things not being properly defined for some reason. Scoping is also an issue with the "polyfill" method.
Note 3: My version of three.js is r69. So there may be differences above.

Three.js plane facing away from camera aligned with viewport

I'm trying to have a plane face away from the camera with same orientation so it's aligned in the viewport.
I have a plane in front of the camera, perfectly aligned to the cameras viewport, and I want to flip it in front of the camera, along the objects Y axis, regardless of camera orientation.
The following will orient my plane to face at the camera and works for any orientation:
target.rotation.copy(camera.rotation);
The following will then flip the plane along the plane's Y axis:
target.rotation.y += Math.PI;
All good so far? Except when the camera rotation has a funky tilt to it, let's say it's looking up and to the left, tilted slightly to the right, the plane's flip is tilted, but not the same way as the camera, leaving me with a plane tilted either to the left or right...
I've tried several things such as:
target.rotation.z -= camera.rotation.z;
Nothing... Thanks for your help.
So the problem I was running into was when the camera was in negative z coordinates. This causes the flip on the Y axis to get messed up.
So basically you would do something like this:
var target = new THREE.Object3D();
//position
target.position.copy(s.camera.position);
target.position.add(THREE.Utils.cameraLookDir(s.camera).multiplyScalar(300));
//rotation
target.rotation.copy(s.camera.rotation);
target.rotation.y += PI;
target.rotation.z = -s.camera.rotation.z;
if (s.camera.position.z < 0) {
target.rotation.z = s.camera.rotation.z;
}
EDIT:
Add the following to appropriate spots in your program.
camera.rotation.eulerOrder = 'XZY';
target.rotation.eulerOrder = 'XZY';
Seems to solve previously encountered tilt issues! (see below)
RESOLVED:
Flipped planes tilted the wrong way in some instances, for example when in negative z coords and also the y rotation is not equal to 0, example: point in space hovering and looking at 0, 0, 0.
This is the solution I was looking for when I found this page (taken from this answer):
mesh.lookAt( camera.position );
The local z-axis of the mesh should then point toward the camera.

Rotating GUI.Box Causes Clipping

I am attempting to rotate 2 different GUI Boxes's on the Z Axis. Each box will have a different Z axis value. The following image shows how I am trying to make them appear(I made the following image in photoshop):
My Problem: I am unable to rotate my boxes on the Z axis without clipping occurring. I can successfully rotate my panels on the x and y axis but not the Z without clipping occurring. Also can I have 2 boxes with a different z rotation using GUI.Matrix (I've read in other questions that this isn't possible)?
This is what happens:
Any ideas how I can achieve the rotation that is shown in my first image?
void OnGUI() {
Matrix4x4 guiMatrixOrig = GUI.matrix;
GUI.matrix = Matrix4x4.TRS(Vector3.zero, Quaternion.Euler(0, 45, 0), new Vector3(1.0f, 1.0f, 1.0f));
GUI.Box (new Rect (10,10,400, 400), "Loader Menu");
GUI.matrix = guiMatrixOrig;
}
This has been asked a while ago but.. if anyone else trys to do something alike he should try to use the GUIUtility.RotateAroundPivot function., moving multiple Boxes without clipping should work that way.

The transform property in CGPathAddEllipseInRect

I am using CGPathAddEllipseInRect to draw a circle and then using that in CAKeyframeAnimation. My issue is that the animation always starts in the same spot. I thought that I could do the following with a CGAffineTransform to make it start in a different point:
CGAffineTransform temp = CGAffineTransformMakeRotation(M_PI / 2);
CGPathAddEllipseInRect(animationPath , &temp, rect);
I do not know what this is doing. When it runs, I don't even see this portion of the animation. It is doing something offscreen. Any help understanding this would be great.
The rotation happens around the origin (0,0) by default, but you want to rotate around the center of the circle, so you have to do additional transformations:
float midX = CGRectGetMidX(rect);
float midY = CGRectGetMidY(rect);
CGAffineTransform t =
CGAffineTransformConcat(
CGAffineTransformConcat(
CGAffineTransformMakeTranslation(-midX, -midY),
CGAffineTransformMakeRotation(angle)),
CGAffineTransformMakeTranslation(midX, midY));
CGPathAddEllipseInRect(animationPath, &t, rect);
Essentially, this chains three transformations: First, the circle is moved to the origin (0,0), then the rotation is applied and afterwards it is moved back to its original position. I've made a little visualization to illustrate the effect:
I chose a square instead of a circle and 45° instead of 90° to make the rotation easier to see, but the principle is the same.

Correct calculations of floats in OpenGL ES

I'm making a game in 3D. Everything is correct in my code, although I'm confused about one thing.
When I setting up my perspective (gluPerspective) I set it to zNear = 0.1f and zFar = 100.0f. So far so good. Now, I also wanna move things just in the x or y direction via glTranslate.... But, the origo starts in the absolute centrum of my screen. Like I have zFar and zNear, why isn't that properly to the x and y coordinates? Now it is like if I move my sprite -2.0f to left on x-axis and make glTranslate... to handle that, it almost out of screen. And the z-axis is not behave like that. That's make it a lot more difficult to handle calculations in all directions. It's quite hard to add an unique float value to an object and for now I just add these randomly to just make them stay inside screen.
So, I have problem calculate corrects value to each object. Have I missed something? Should I change or thinkig of something? The reason that this is important is because I need to know the absolute left and right of my screen to make these calculations.
This is my onSurfaceChanged:
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
GLU.gluPerspective(gl, 45.0f, (float)width / (float)height,
0.1f, 100.0f);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
}
Thanks in advance!
When you use gluPerspective you are transforming your coordinates from 3D world space into 2D screen space, using a matrix which looks at (0,0,0) by default (i.e. x= 0, y = 0 is in the center of the screen). When you set your object coordinates you are doing it in world space, NOT screen space.
If you want to effectively do 2D graphics (where things are given coordinates respective to their position on the screen you want to use gluOrtho2D instead.

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