How can I check if there is a collision? - events

In my game, I have a ball and ground. The ball is falling and collides with the ground.
But how can I check if the ball has collided? I've added a script to the ball, and got the following code:
void OnCollisionEnter (Collision collisionInfo)
{
print ("collision!");
Destroy(this);
}
Problem is that nothing happens, am I using the wrong event? Ultimately I would want to trigger an animation.

Your code would work if you were using 3d colliders. However, since you're using 2d, there's a separate event called OnCollisionEnter2D, so just change your event to this:
void OnCollisionEnter2D (Collision2D collisionInfo)
{
print ("collision!");
Destroy(this);
}

Related

Slowly move a circle in PIXIJS

I have a circle with PIXI and I need that when the touch is fulfilled another object said circle returns to its original position, but it happens that I do not know any function or method for the movement to be appreciable, all I have achieved is that it disappear and appear in its initial position. How did the transition happen?
Just add the movement into rendering loop
I use PIXI.tickerTicker() for loop
let ticker = new PIXI.ticker.Ticker();
the rendering loop in your situation should be
function loop(){
renderer.render(stageContainer);
yourCircle.position.x += moveSpeed; //your question
if(resetCirclePosition)
yourCircle.position.x = defaultPos;
}
and then to start ticker use
ticker.add(loop);
ticker.start();
Look at ticker documentation http://pixijs.download/dev/docs/PIXI.ticker.Ticker.html

Unity3D: How to "chain" animations without resetting?

I imported a cube mesh that contains four smaller sub-cubes.
The mesh also contains an animation that pushes the smaller cubes out of the big one. When this is done, one of the small cubes "splits" again (it's not really splitting - it just pushes four children out again).
I'd like to trigger these animations when the user clicks on the big cube.The animation was initially exported as one clip but I cut it in half so that I can either trigger the first or the second split.
I attached a Box Collider to the big cube to be able to get an OnMouseDown event and from there I pass an int parameter to my AnimationController that starts the appropriate animation:
public class ClickToAnimate : MonoBehaviour {
private Animator _animator;
private int _clicks = 1;
void Start()
{
_animator = GetComponent<Animator>();
}
void OnMouseDown()
{
_animator.SetInteger("Clicks", _clicks);
if (_clicks == 3)
{
_clicks = 1;
}
else
{
_clicks++;
}
}
}
The state switching works fine but when I transition from FirstSplit to SecondSplit, the first animation is reverted so that the four medium cubes are driven back in the big cube before the second animation is played.
I tried enabling "Apply Root Motion" but that doesn't help (probably because the big cube is never actually moving?). So how can I "chain" these animations without resetting them in each step? Are my general ideas regarding the AnimationController and animation splitting correct to handle this and what am I missing?

How to give control back to animation in Unity3D once altering objects location

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.

Unity 3D Spinning a gameobject

I am trying to spin a 3D Gameobject in unity. It is actually a cylinder with just a texture of a poker chip on it. I want to spin it 360 degrees once it has collided with a raycast. It is working just fine in the Unity emulator, however, on the device itself the chip comes to a stop after its spin and then continues to spin in an endless loop. Here is a snippet of the code in question. Thank you for any help in advance.
// Spin the chip
if (Animate) {
if (Speed > 0 && Chip.tag.Contains("Chip")) {
Chip.transform.Rotate(0, Speed*Time.deltaTime, 0);
Speed -= 3;
Debug.Log(Speed);
}
else {
// Reset
Animate = false;
Speed = 360;
Chip.transform.localRotation = Quaternion.Euler(0.0,0.0,0.0);
}
}
To summorize this the best I can the gameobject Chip is assigned when it collides on raycast as such
// Set the chip
Chip = hit.transform;
Everything is done in the update function. Once the raycast hits it calls a betting function then after the betting is calculated it changes the Boolean Animate to true causing the spinning of the chip.
Something is setting Animate = true in some other code, hard to tell whats going on without seeing the rest of it.
Put some debug next to every spot where Animate is set to true, you should see something else setting it, only possible explanation as to why it continues to spin.
Another option is to use the Animation tool and instead of rotating, you just play the animation which performs the rotation for you.
Edit: Chances are its around the touch code, cause when you debug in the editor your using key strokes. A gotcha I've experienced a few times.
James Gramosli is correct in that some other code is triggering the animation again and it is most likely your touch code. It is a common problem when moving between editor and a touch-enabled device. You can determine if this is the case by using the UnityRemote to verify the control flow of your code.
That said, I would change your code to the following which removes the spin code from the Update loop that runs every frame. It is a small optimization, but primarily it cleans up the architecture and makes it more modular and a little neater.
It is not clear from your code snippet, but I will assume you are using UnityScript.
In your script that handles the touch code when you click on the chip, insert this line:
hit.transform.SendMessage("Spin", hit.transform, SendMessageOptions.DontRequireReceiver);
Put this code in a separate script called "SpinChip" and then add the script to your chip object.
var StartSpeed = 360.0;
var Deceleration = 3.0;
function Spin()
{
if (Animating)
{
print("Chip is already spinning, not starting another animation");
return;
}
/*
This code isn't necessary if this exists in a separate script and is only ever attached to the clickable chip
if (!gameObject.tag.Contains("Chip"))
{
print("That wasn't a chip you clicked");
return;
}
*/
print("Chip has been told to spin");
StartCoroutine(SpinningAnimation);
}
function SpinningAnimation()
{
print("Chip spin start");
transform.localRotation = Quaternion.identity;
Speed = StartSpeed;
Animating = true;
while (Speed > 0)
{
transform.Rotate(0, Speed*Time.deltaTime, 0);
Speed -= Deceleration;
yield; // wait one frame
}
print("Chip has completed the spin");
Animating = false;
}
What this code does is create a co-routine that runs once per update loop when activated that will spin the chip for you, and is independent of your actual button clicking code.
var rotSpeed: float = 60; // degrees per second
function Update(){
transform.Rotate(0, rotSpeed * Time.deltaTime, 0, Space.World);
}
Here is a code that rotates your game object, you can use it just with a vector 3 :transform.Rotate(x, y, z); or with Space transform.Rotate(x, y, z, Space.World);
rotSpeed is the rotation speed.
In your update function . The Bool variable Animate may becoming true . This may be reason your cylinder continues to rotate.
Other Solution is : You can create an animation of your cylinder and then take a stopwatch . So that after sometime you can stop you animation using the time of stopwatch

XNA: Identifying identical sprites created with for loop

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
}
}

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