How to ignore one OnTrigger Collider in an Object? - visual-studio

I have 3(Three) BoxCollider2D components where 2(two) have OnTrigger checked in my Object and both have different functions. Due to having OnTrigger on both, the projectiles I am casting collide with the wrong collider and instead activate that function. Is there a way to ignore 1(one) OnTrigger collider?
I have already tried Layer-based collision detection and set up a layer. Unfortunately, the object now collides with the collider which eliminates the player on collision

However, there are several ways to solve this problem. All kinds of physics.checks as well as raycasts but this code helps you to ignore the obstacle collider.
public Collider2D playerCollider;
public Collider2D obstacleCollider;
public void Start() => Physics2D.IgnoreCollision(playerCollider, obstacleCollider);

I have a very simple script I use to handle collisions in my games.
It's very easy to setup because it makes everything drop and draggable, which is a much easier way to program.
Below is the script and below that is instructions on how to use. Note it is a layer based system, but you can select multiple layers.
[System.Serializable]
public class TriggerEvent : UnityEvent<Collider> { }
[System.Serializable]
public class CollisionEvent : UnityEvent<Collision>{ }
public class EnterEvent: MonoBehaviour
{
public TriggerEvent TriggerEnteredEvent;
public CollisionEvent CollisionEnteredEvent;
[SerializedField]private LayerMask validLayers;
// Initalize Event System
void Awake()
{
if (OnTriggerEnter == null)
{
TriggerEnteredEvent = new TriggerEvent();
}
if (OnCollisionEnter == null)
{
CollisionEnteredEvent = new CollisionEvent();
}
}
// Called if transform is a trigger
void OnTriggerEnter(Collider collider)
{
if (validLayers == (validLayers | 1 << collider.gameObject.layer))
{
TriggerEnteredEvent?.Invoke(collider);
}
}
// Called if transform is not a trigger
void OnCollisionEnter(Collision collision)
{
if (validLayers == (validLayers | 1 << collision.gameObject.layer))
{
CollisionEnteredEvent?.Invoke(collision);
}
}
}
This is how it would work, and in this example I will be "coding" it from the perspective of a Bullet.
Basically I want to check if I (The Bullet) hits either the terrain or an enemy then call the relevent funcitons in the Bullet class respectively.
Obviously if I hit an enemy I want to deal damage.
So this will be my example bullet class
public class Bullet : MonoBehaviour
{
public int BulletDamage = 10;
public int BulletSpeed = 5;
void FixedUpdate() => transform.position = Vector3.Lerp(transform.position, transform.position + transform.forward * speed * Time.deltaTime, 1f);
public void OnEnemyHit(Collision collision)
{
// Try to get the enemy script
Enemy enemy = collision.gameObject.transform.GetComponent<Enemy>();
if (enemy != null)
{
enemy.DealDamage(this.BulletDamage);
}
}
public void OnTerrainHit(Collision collision)
{
Destroy(this.gameObject);
}
}
Add the EnterEvent script to the bullet.
Add the Bullet Script to the bullet.
There will be a space on the Inspecter where you can add your events. It should have a Plus and Minus in the top right corner. Press the plus.
From the inspector drag the bullet in game GameObject to the open space provider.
In the dropdown to the right, click on it, look for the Bullet Script, and select the OnEnemyHit function from it.
Create another event, do the exact same, but this time select the OnTerrainHit funciton instead - now but would be called in the order you added them.
Just underneath the event system should be the be able to see a dropdown for the Layers. Select all the layers you want your bullet to interact with. In this case it will be the Enemy and Terrain.
Finally remember to setup your layers properly. Ensure the Enemy has an Enemy Layer, the Terrain has a Terrain Layer, Bullet bullet layer and Player has a Player Layer

Related

how to destroy an object in unity

how to destroy an object in unity?
I know you have to type the command
Destroy();
but what I'm saying is that I don't know what to put between brackets.
I have tried many different ways:
public GameObject motor;
Destroy(motor);
but it does not work
using System.Collections;
using UnityEngine;
public class LogRotation : MonoBehaviour
{
[System.Serializable] //this will allow us to edit it in the editor
//a custom class representing a single rotation "element" of the log's rotation pattern
private class RotationElement
{
//to get rid of an obnoxious warning about these fields not being initialized
#pragma warning disable 0649
public float Speed;
public float Duration;
#pragma warning restore 0649
}
[SerializeField] //attribute making private fields editable in the Unity Editor
//the aforemention full rotation pattern of the log
private RotationElement[] rotationPattern;
//this will be set to the Wheel Joint 2D from the LogMotor object
private WheelJoint2D wheelJoint;
//something has to actually apply a force to the log through the Wheel Joint 2D
private JointMotor2D motor;
private void Awake()
{
//setting fields
wheelJoint = GetComponent<WheelJoint2D>();
motor = new JointMotor2D();
//starting an infinitely looping coroutine defined below right when this script loads (awakes)
StartCoroutine("PlayRotationPattern");
}
private IEnumerator PlayRotationPattern()
{
int rotationIndex = 0;
//infinite coroutine loop
while (true)
{
//working with physics, executing as if this was running in a FixedUpdate method
yield return new WaitForFixedUpdate();
motor.motorSpeed = rotationPattern[rotationIndex].Speed;
//hard coded 10000, feel free to experiment with other torques if you wish
motor.maxMotorTorque = 10000;
//set the updated motor to be the motor "sitting" on the Wheel Joint 2D
wheelJoint.motor = motor;
//let the motor do its thing for the specified duration
yield return new WaitForSecondsRealtime(rotationPattern[rotationIndex].Duration);
rotationIndex++;
//infinite loop through the rotationPattern
rotationIndex = rotationIndex < rotationPattern.Length ? rotationIndex : 0;
}
}
}
TLDR; Destroy(motor.gameObject), but it will not work if JointMotor2D doesn't inherit MonoBehaviour.
Destroy(obj) can be used to destroy a component too.You need reference it to the game-object to destroy it.
Destroy(GetComponent<RigidBody>()) would remove the RigidBody out of the game-object, rather than removing the object itself.
Destroy(motor.gameObject) should do the trick.
But upon seeing your code, it may not.As it seems like JointMotor2D isn't a MonoBehaviour, aka it doesn't exists in the game-world, hence you can't destroy it.
Depending on what your trying to destroy, you have to find a reference to it.
Simplest way is to reference it in the inspector. Or destroy itself if that is already the object you want to destroy:
// Drag-drop the object in the inspector
[SerializeField]
private GameObject toDestroyLater;
private void DestroyObject() {
Destroy(toDestroyLater);
// Destroys self
// (Aka, whatever game-object this script is attached to)
Destroy(this.gameObject);
}

Solid plane in Unity

So I created a plane to be my floor in my unity project. I also assigned that with a mesh collider and a box collider and set it with convex but not as trigger.
I then created an item with also a mesh and sphere collider and set it to use gravity, since I wanted the item to fall onto the floor. But when I start the game, it still falling past the floor.
I have tried to find a solution already in YT, here and other places, but the only ideas they give is assigning a collider. This doesn't work as for me.
I also tried to fill the colliders with materials but cannot assign anything with it.
I also tried to write a code, but this does not help either.
Does anyone have an idea how to solve it?
public class IsGrounded : MonoBehaviour
{
Vector3 velocity;
public float gravity = -9.81f;
public Transform groundCheck;
public float groundDistance = 0.4f;
public LayerMask groundMask;
bool isGrounded;
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
isGrounded = Physics.CheckSphere(groundCheck.position, groundDistance, groundMask);
if (isGrounded && velocity.y < 0)
{
velocity.y = -2f;
}
}
}
So finally, I manage to find the solution from a helpful yt video.
What I needed to change was to deactivate both, the floor and the items, the trigger event. Since Unity does not allow you to use without kinematic and convex, I just clicked on convex and nothing changes. Now, items will not fall down the plane (still can happen, like when I throw the item down, it will sometimes go through).

How to check which objects collide

i have an example : player object, obstacle_1 object and obstacle_2 object. How do I check which one player collides with? I mean I want to do script_1 for colliding player with obstacle_1 and do script_2 when player collides with obstacle_2. Example:
private void OnTriggerEnter2D(Collider2D collision)
{
//script 1 when this object(player) collides with obstacle_1;
//script 2 when this object(player) collides with obstacle_2;
}
It seems like you're asking how to differentiate between objects. There are many ways of doing so, and it's hard to say which will work best for you since you didn't give a lot of context. Here are some ideas:
One of the simplest ways would be comparing the object's names:
private void OnTriggerEnter2D(Collider2D collision)
{
if(collision.gameObject.name == "Obstacle_1"){
//React to obstacle 1
}
else if (collision.gameObject.name == "Obstacle_2"){
//React to obstacle 2
}
}
I really wouldn't encourage this though, since the name of the objects can be changed quite easily.
You could add Tags to obstacle_1 and obstacle_2, and compare tags, like:
private void OnTriggerEnter2D(Collider2D collision)
{
if(collision.gameObject.CompareTag("Obstacle 1")){
//React to obstacle 1
}
else if (collision.gameObject.CompareTag("Obstacle 2")){
//React to obstacle 2
}
}
This is a bit better, since changing tags is not as easy as changing names, but there's still room for spelling errors. Comparing strings is not very efficient either, especially if done frequently.
You could create different components for obstacle_1 (BouncyObstacle) and obstacle_2 (SpikeObstacle), and then have your player try to get these components, like:
private void OnTriggerEnter2D(Collider2D collision) {
if(collision.gameObject.TryGetComponent(out BouncyObstacle bouncyObs){
// React to bouncy obstacle
}
else if(collision.gameObject.TryGetComponent(out SpikeObstacle spikeObs)
{
//React to spike obstacle
}
}
This is a little bit better, but every time you want to add a new obstacle, you need to add an if to your player code.
Again, it's hard to say which solution would be best. From your snippet, it seems like the player class is responsible for reacting to the obstacles, and this means that every time you want to add a new obstacle, you need to open the player class and change the OnTriggerEnter method. Perhaps it would be better to move this responsibility to separate components. That way you'll be able to add as many obstacles you want without changing any of the previous classes you made. Something like:
public class BouncyObstacle : MonoBehaviour
{
void OnTriggerEnter2D(Collider2D other)
{
if(other.TryGetComponent(out Player player))
{
player.Bounce();
}
}
}
public class SpikeObstacle : MonoBehaviour
{
void OnTriggerEnter2D(Collider2D other)
{
if(other.TryGetComponent(out Player player))
{
player.Kill();
}
}
}
// etc..

How to cache TextureAtlas results?

When using a TextureAtlas to create a Sprite with the createSprite method, the LibGDX documentation says: This method uses string comparison to find the region and constructs a new sprite, so the result should be cached rather than calling this method multiple times.
How do I cache these results? Is it just a variable I create to store the created sprite? If so then how do I create different copies of the same sprite?
Each time you use the createSprite method, a new Sprite gets created. Usually you'd have one sprite per enemy for example. Let's say that you have a class Frog which is one of your enemies. It should look like this (pseudo-code):
public class Frog {
private Sprite sprite;
public Frog(TextureAtlas atlas) {
sprite = atlas.createSprite("frog");
}
public void update(float deltaTime) {
// update the sprite position
}
public void render(Batch batch) {
sprite.draw(batch);
}
}
Now each Frog would have its own Sprite. This is necessary, since all frogs can be in different places. The position will be configured via the Sprite. You will create the sprite just once in the constructor and all of those sprites share the same TextureRegion of the same TextureAtlas, which will result in a good performance, since there won't be many texture switches on the graphics card, when you render your frogs.

How to get location of mouse in JavaFX?

I am a beginner in java(fx).
How do you get the mouse location in x and y in JavaFX? I tried using AWT's MouseInfo(also imported it), but it's not working. I also saw the code for it in Ensembles(that dragging the ball-window in "advanced stage", that's what I need to do, drag my undecorated JavaFX stage), but it also doesn't work. I am using FXML with controller, and I guess that's the main problem. Should I switch back to the single-file simple JavaFX? I know FXML is better for laying out the UI, but I can't get many of such codes to work. Or do I need some other sort of code for my controller? Please give proper codes with comments wherever possible.
If you need a bit of my code to inspect, feel free to ask.
There are a few items in your question - I'll tackle them one at a time.
How do you get the mouse location in x and y in JavaFX?
Add a mouse event handler to the appropriate JavaFX component that you want to track the mouse location in. A JavaFX mouse event will report multiple different kinds of co-ordinates. The x and y co-ordinates are relative to the top left corner of the node whose location is being monitored. The sceneX and sceneY co-ordinates are relative to the scene's top left 0,0 co-ordinates. The screenX and screenY co-ordinates are relative to the top left 0,0 co-ordinates of the current screen.
These co-ordinates are documented in the MouseEvent documentation. There is extra information in understanding co-ordinate systems in the Node and Scene documentation.
import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.event.*;
import javafx.scene.*;
import javafx.scene.control.*;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.VBox;
import javafx.stage.*;
public class MouseLocationReporter extends Application {
private static final String OUTSIDE_TEXT = "Outside Label";
public static void main(String[] args) { launch(args); }
#Override public void start(final Stage stage) {
final Label reporter = new Label(OUTSIDE_TEXT);
Label monitored = createMonitoredLabel(reporter);
VBox layout = new VBox(10);
layout.setStyle("-fx-background-color: cornsilk; -fx-padding: 10px;");
layout.getChildren().setAll(
monitored,
reporter
);
layout.setPrefWidth(500);
stage.setScene(
new Scene(layout)
);
stage.show();
}
private Label createMonitoredLabel(final Label reporter) {
final Label monitored = new Label("Mouse Location Monitor");
monitored.setStyle("-fx-background-color: forestgreen; -fx-text-fill: white; -fx-font-size: 20px;");
monitored.setOnMouseMoved(new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent event) {
String msg =
"(x: " + event.getX() + ", y: " + event.getY() + ") -- " +
"(sceneX: " + event.getSceneX() + ", sceneY: " + event.getSceneY() + ") -- " +
"(screenX: " + event.getScreenX()+ ", screenY: " + event.getScreenY() + ")";
reporter.setText(msg);
}
});
monitored.setOnMouseExited(new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent event) {
reporter.setText(OUTSIDE_TEXT);
}
});
return monitored;
}
}
I tried using AWT's MouseInfo(also imported it), but it's not working.
Don't do this. Mixing different graphical toolkits (for example Swing/AWT and JavaFX) is an advanced topic. In general, if you are writing a JavaFX application, avoid importing anything from the java.awt namespace and the javax.swing namespace. You only really need to use those if you have a large, existing Swing based application or framework that you need to inter-operate with your JavaFX application. In this case, you don't have that situation.
I also saw the code for it in Ensembles(that dragging the ball-window in "advanced stage", that's what I need to do, drag my undecorated JavaFX stage), but it also doesn't work.
I tried the Ensemble Advanced Stage sample and dragging that stage around worked for me.
Another sample for dragging an undecorated stage in JavaFX is in the answer to How to draw a clock with JavaFX 2? which has associated sample code. The method used to make the undecorated stage draggable for the clock sample is:
/** makes a stage draggable using a given node */
public static void makeDraggable(final Stage stage, final Node byNode) {
final Delta dragDelta = new Delta();
byNode.setOnMousePressed(new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent mouseEvent) {
// record a delta distance for the drag and drop operation.
dragDelta.x = stage.getX() - mouseEvent.getScreenX();
dragDelta.y = stage.getY() - mouseEvent.getScreenY();
byNode.setCursor(Cursor.MOVE);
}
});
byNode.setOnMouseReleased(new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent mouseEvent) {
byNode.setCursor(Cursor.HAND);
}
});
byNode.setOnMouseDragged(new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent mouseEvent) {
stage.setX(mouseEvent.getScreenX() + dragDelta.x);
stage.setY(mouseEvent.getScreenY() + dragDelta.y);
}
});
byNode.setOnMouseEntered(new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent mouseEvent) {
if (!mouseEvent.isPrimaryButtonDown()) {
byNode.setCursor(Cursor.HAND);
}
}
});
byNode.setOnMouseExited(new EventHandler<MouseEvent>() {
#Override public void handle(MouseEvent mouseEvent) {
if (!mouseEvent.isPrimaryButtonDown()) {
byNode.setCursor(Cursor.DEFAULT);
}
}
});
}
I am using FXML with controller, and I guess that's the main problem. Should I switch back to the single-file simple JavaFX? I know FXML is better for laying out the UI, but I can't get many of such codes to work.
Lack of understanding and familiarity with the underlying JavaFX APIs is probably your main problem rather than use of FXML. However the additional complexity fxml implies together with the lighter documentation and samples for it on the web may be contributing to your hardships. If use of FXML is making it difficult for you to understand how to get some JavaFX functions to work, I advise to stop using FXML for now. Code the logic by hand using the Java APIs and refer to the Oracle JavaFX tutorials and the Ensemble sample code when you encounter things which are difficult for you.
Once you are comfortable coding directly to the JavaFX API, switch back to using FXML for larger projects which contain many GUI elements. The FXML elements and attributes themselves are built almost completely upon reflection of the standard JavaFX APIs. So, if you understand the core JavaFX APIs, you also understand almost everything about FXML.
Please do not post follow up comments to this answer (as this answer is long enough as it is). If you have new questions, create a new question (one question per question).
What about using Robot for that purpose ?
http://docs.oracle.com/javase/1.5.0/docs/api/java/awt/Robot.html
Using Robots, it is different from posting event to AWT event queue. Events are generated in the native event queue. Actually, with Robot.mouseMove you will not only set mouse position and not only get position.
For getting mouse position, you may stick to MouseInfo
import java.awt.MouseInfo;
// get the mouse's position
Point p = MouseInfo.getPointerInfo().getLocation();
It's not working: are you with Mac ? Which is your version of JavaFX ? seems to be issues corrected for FX8. For mac only, you may use
com.sun.glass.ui.Robot robot =
com.sun.glass.ui.Application.GetApplication().createRobot();
// getPosition of the mouse in Mac
int x = robot.getMouseX();
int y = robot.getMouseY();
JavaFx 8 WindowEvent doesn't provide the (x,y) location of the mouse, unfortunately. I solved this (and it works fine) by using the AWT MouseInfo like this:
Tooltip t = new Tooltip();
Tooltip.install(yournode, t);
t.setOnShowing(ev -> {// called just prior to being shown
Point mouse = java.awt.MouseInfo.getPointerInfo().getLocation();
Point2D local = yournode.screenToLocal(mouse.x, mouse.y);
// my app-specific code to get the chart's yaxis value
// then set the text as I want
double pitch = yaxis.getValueForDisplay(local.getY()).doubleValue();
double freq = AudioUtil.pitch2frequency(pitch);
t.setText(String.format("Pitch %.1f: %.1f Hz %.1f samples", pitch, freq, audio.rate / freq));
});

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