I have an animation with about 20 frames. I need to be able to access local transforms for each bone for a given animation frame. I know how to access the bone and its local transform (a sample of the code)
Transform root, spine1;
getChildFromName(gameObj, "Jnt_Root", out root);
getChildFromName(root, "Jnt_Spine1", out spine1);
spine1.localRotation = someValue;
All of this works fine, but I don't know the values I'm getting are from which animation frame? I assume its from frame 1 (can verify using debugger but that's not the point)
The questions is how to get and set these values for a specific frame? Thanks!
Something like this should work for getting the current transforms:
AnimationState state = animation["your_animation"];
state.enabled = true;
state.normalizedTime = (1.0f/totalAnimationTime) * specificFrame;
animation.Sample();
// get all transforms of this animation, extract your root and spine from here.
Transform[] transforms = animation.gameObject.GetComponentsInChildren<Transform>();
Or if you're trying to sample while the animation is running you could do something like:
if(animation["your_animation"].normalizedTime > 0.3 && animation["your_animation"].normalizedTime < 0.5) {
//... do something at this point in time. You'll have to figure out the frame
//from the time
}
Last I checked you can't explicitly extract a particular frame. But if you know the total length of your animation (time-wise), you can move the animation to that point with something like: (1.0f/totalAnimationTime) * specificFrame; (this assumes the keyframes are uniformly spaced.)
Once stored you should be able to modify the transforms directly but I've never tried.
Related
Skeletal animation issue (always plays default T-pose (keyframe 0) in (looped) animations using AnimationAction.play()).
Animations are imported from an .FBX file with a skeleton and animations using the FBXLoader.
I've trimmed the AnimationClip.tracks array() to remove the first keyframe(s), but it keeps including the base keyframe 0 T-pose during animations.
I tried emptying the AnimationClip.tracks array. If I then play() the associated AnimationAction, it still sets up some pose, suggesting the problem might not lie in the AnimationClip at all, but rather in parent Action/Mixer.
I've also tried offsetting the AnimationAction using "startAt(0.0333..)". But it still adds in the base pose during play().
//setup mixer for object
scene.mixer = new THREE.AnimationMixer( scene.obj );
// actions array (quick reference)
scene.actions = [];
for (i in scene.obj.animations) {
scene.actions.push(scene.mixer.clipAction(scene.obj.animations[ i ] ));
// offset keyframe 0 (doesnt work since it still uses the keyframe 0 "T-pose" when the animation has finished playing and optionally loops)
scene.actions[i].startAt(0.0334);
// tried trimming with subClip fn, but again it'll throw in the T-pose.
subClip(scene.actions[3].getClip(), 0.03333333432674409 /* 30 fps: skip first frame # 0.03333333432674408 */, 2);
// emptying the tracks array also doesnt work, since its still setting bones when I play/stop the AnimationAction.
scene.actions[3].getClip().tracks = [];
scene.actions[3].getClip().resetDuration();
}
function subClip(clip, start, end) {
for (i in clip.tracks) {
var track = clip.tracks[i];
// (we depend on internal behaviour of trim() which uses Array.slice,
// and doesn't modify the original array).
clip.tracks[i].trim(start, end);
// Once trim has been called, our track now has its own copies of
// times/values, and no shared data. It's now safe to modify in-place,
// which shift() does.
clip.tracks[i].shift(-start);
}
// after modifying (key)frames, reset duration to new length
clip.resetDuration();
}
I expect none of the keyframe 0 data to be used during animations. Especially on loop: they quite visibly stutter. (because of the jump in position + strange interpolation to the next pose).
Solved this by exporting all animations into one large model file instead of a seperate file for every animation. Afterwards you can manually cut them up into seperate clips and it'll work just fine.
I have a character made of up child objects that are animated using Unity3D's animation system.
While the player is walking, I can programmatically move the hand object up to catch a ball using the following code.
hand.position.y = ball.transform.position.y;
I need the hand object to go back to following the walk animation after it touches the ball, but instead it just stays at the exact position since it was set.
You want to use inverse kinematics and let Unity do the work of figuring out positioning for you. Here's a quick-and-dirty (untested) example for catching a ball (it's in C#, but it should be pretty similar for UnityScript):
// in a script on the same GameObject as your animation controller
bool isCatching;
Transform ball;
void OnAnimatorIK (int layer) {
if (isCatching) {
// set position and rotation weights for your catching hand
animator.SetIKPosition(AvatarIKGoal.RightHand, ball.position);
animator.SetIKRotation(AvatarIKGoal.RightHand, ball.rotation);
} else {
// return your position and rotation weights back to their defaults (probably 0f?)
}
}
You'll need to do some work (possibly raycasting or just checking distance and direction) to determine when to set the isCatching flag to true, and you'll want to play with the weights for position and rotation to make it look natural. The IK manual entry has more detailed information.
If I do:
actor.setOrigin(0, 0);
actor.setRotation(45);
actor.setOrigin(actor.getWidth() / 2, actor.getHeight() / 2);
It appears that on the last setOrigin call, the actor gets repositioned to the location it would've been if actor.setRotation(45) would have been called after its latest origin was set.
What do I do to make it so that the latest origin of the actor is only used for future "scale" and "rotation" actions?
Okay so i looked in the source code of libgdx, and i'll tell you the short answer.
Basically when you set the origin or the rotation, you just change a variable named "originx", "originy" and "rotation". So every call to setOrigin will overwrite the values set in previous calls.
And every time you draw the actor, it recalculates the bounds using the current variable.
To be clear, setOrigin looks like this :
public void setOrigin (float originX, float originY) {
this.originX = originX;
this.originY = originY;
}
So the precedent setOrigin is lost.
The reposition of the actor itself in your case does not change, but the position of the displayed sprite or texture will change.
It is calculated in this order:
Position -> Origin -> Scale -> Rotation
See: Sprite.java (method: "getVertices ()")
When you change the Origin point of an already rotated element, the point in the plane around which the rotation occurs changes and the sprite will be drawn in a different place (the actor's position in this case does not change).
I use Snap.svg to create a simple card game. I loaded drawed cards from file and moved them to specific location using matrix translate.
It's svg element now looks kinda like this:
<g id="card11" inkscape:label="#g3908" transform="matrix(1.5621,0,0,1.5621,625.1085,529.3716)" cardposition="4" style="visibility: visible;" class="card inhand hand-4 ofplayer1">...</g>
However, now I'm trying to animate them to a specific position (same for all cards) using this:
function animateTo(object, x, y, scaleX, scaleY, time) {
var matrix = object.transform().localMatrix;
var added = new Snap.Matrix();
added.translate(x, y);
added.scale(scaleX, scaleY);
added.add(matrix);
object.animate({transform: added}, time);
}
or something like this:
function animateTo(object, x, y, scaleX, scaleY, time) {
object.animate({transform: "t100,100"}, time);//this one I tried to use to understand how snap animations works
}
And here is my problem - when it animates, it allways first deletes the animation matrix of object and start animate from it's original location with blank matrix (where the object would be without transform attribute).
For example, when I tried:
var matrix = object.transform().localMatrix;
object.animate({transform: matrix}, time);
I expected it will do nothing, but my object blinks to the top left corner (blank matrix) and animates to position where it should stay.
What am I doing wrong? I need to animate that object from some matrix state to another (ideally the same one for every object). Is it somehow possible? Like I can specify start transform attribute somehow?
Thanks.
According to Ian's advice, I've used toTransformString:
object.animate({transform: matrix.toTransformString()}, time);
but of course, I had to use it in previous transformations too using
object.attr({transform: added.toTransformString()});//this
//object.transform(added);//instead of this
However, getting local matrix still works as expected. Animation now works and I can use matrix.translate() - to relative move the object or object.animate({transform: "t100,100"}, time).
I also can modify a,b,c,d,e,f attributes of the matrix directly. (or use transform: "T100,100")
It works!
Thanks!
G'day all,
In short, I'm using a for loop to create a bunch of identical sprites that I want to bounce around the screen. The problem is how do I write a collision detection process for the sprites. I have used the process of placing rectangles around sprites and using the .intersects method for rectangles but in that case I created each sprite separately and could identify each one uniquely. Now I have a bunch of sprites but no apparent way to pick one from another.
In detail, if I create an object called Bouncer.cs and give it the movement instructions in it's update() method then create a bunch of sprites using this in Game.cs:
for (int i = 1; i < 5; ++i)
{
Vector2 position = new Vector2(i * 50, i * 50);
Vector2 direction = new Vector2(i * 10, i * 10);
Vector2 velocity = new Vector2(10);
Components.Add(new Bouncer(this, position, direction, velocity, i));
}
base.Initialize();
I can draw a rectangle around each one using:
foreach (Bouncer component1 in Components)
{
Bouncer thing = (Bouncer)component1;
Rectangle thingRectangle;
thingRectangle = new Rectangle((int)thing.position.X, (int)thing.position.Y, thing.sprite.Width, thing.sprite.Height);
But now, how do I check for a collision? I can hardly use:
if (thingRectangle.Intersects(thingRectangle))
I should point out I'm a teacher by trade and play with coding to keep my brain from turning to mush. Recently I have been working with Python and with Python I could just put all the sprites into a list:
sprites[];
Then I could simply refer to each as sprite[1] or sprite[2] or whatever its index in the list is. Does XNA have something like this?
Please let me know if any more code needs to be posted.
Thanks,
Andrew.
One solution, which I use in my game engine, is to have a Logic code run inside the objects for every game Update, ie. every frame. It seems you already do this, according to the variable names, which indicate you run some physics code in the objects to update their positions.
You might also want to create the collision rectangle inside the Bouncer's constructor so it's more accessible and you make good use of object oriented programming, maybe even make it an accessor, so you can make it update every time you call it instead of manually updating the bounding/collision box. For example:
public Rectangle #BoundingBox {
get { return new Rectangle(_Position.X, _Position.Y, width, height); }
}
Whichever way works, but the collision checks can be run inside the Bouncer object. You can either make the reference list of the Bouncer objects static or pass it to the objects itself. The code for collisions is very simply:
foreach(Bouncer bouncer in Components) //Components can be a static List or you can pass it on in the constructor of the Bouncer object
{
if (bouncer.BoundingBox.Intersects(this.BoundingBox))
{
//they collided
}
}