According to this article is possible to solve collision problems with fast moving objects in unity.
If you have particle system firing 1 sphere particle (ball throw for example) with collider and gravity modifier. And another moving collider with rigidbody (baseball bat for example), is there any possibility to make these object to NOT going through when they will collide in "high speed"? You cannot set "collision detection" on particle.
For better understainding I am adding two screenshots bellow.
Feel free for asking any question.
Collider(wall) is not moving, particle will bounce
Collider(wall) is moving towards ball with speed of "swing", particle goes through
The problem is because your objects are moving at a speed that they go through the collider. Say your object would move 10 units a frame, and it was 1 unit away from the collider. If the collider was 5 units long, it wouldn’t stop the moving object. This is because the next update will push it too far ahead of the next object.
First, don’t use a particle system for this. Just use a Rigidbody, because it is easier to handle in these situations.
You could solve this by doing a sweep test. A sweep test checks for colliders, where the object is going. You could just stop it from moving at the point it hit.
Rigidbody rb;
void Start()
{
rb = GetComponent<Rigidbody>();
}
void Update()
{
Sweep();
}
void Sweep()
{
RaycastHit hit;
if (Physics.SweepTest(rb.velocity, out hit, rb.velocity.magnitude))
{
rb.velocity = rb.velocity.normalized * hit.distance;
}
}
Make sure this script is on your ‘baseball’, and add force somewhere in this script. Make sure that you are not using particle system, but you are using Rigidbody.
This was untested; let me know if it doesn’t work or you get an error.
Related
I made the endless movement of the object and its repulsion from the walls, but it does not always work correctly. At rounded corners (sometimes even at a straight wall), it just gets stuck and stops moving altogether, or moves slowly to the point where it stops moving. What can this be related to and how can it be fixed?
private void FixedUpdate() {
rb.velocity = direction * normalSpeed;
lastDirection = direction;
}
private void OnCollisionEnter2D(Collision2D collision) {
//Repulsion from objects.
direction = Vector3.Reflect(lastDirection.normalized, collision.GetContact(0).normal);
}
There is a small distance between the objects, but the circle seems to stick to the wall and moves with it until it collides with another collider:
Example
there are objects under the circle that also have colliders, but the collision between them is not considered, since they have the same layer (in the settings, I disabled the collision for objects on the same layer). What can be done to fix this error and what can it be related to?
The object in the general scale:
Example
I tried to increase the size of the wall collider, tried to change polygon collider to box collider, connect composite collider, changed the mechanics of the object movement (in these cases, the movement could work incorrectly), but the result was always the same - the jams (sticking to the wall) continued.
It is difficult to answer your question without having more information, but I can suggest if you are using physics to move your objects - utilize physic materials and remove code that changes direction manually in OnCollisionEnter. Using physic materials you can easily make your object bounce from colliders of your choice without losing velocity.
I wanted to make a shot with a particle system and if one of the particles collides with something, then the opponent should get damage. I use the trigger function because I want the particles to continue flying after colliding. And in case you are wondering why I don't use a raycast: if I work with a raycast, the opponent gets harm without the particles arriving.
My Code:
private void OnParticleTrigger()
{
if (!hitObjects.Contains(other.gameObject))
{
other.GetComponent<IDamageable>().GetDamage(PlayerScript.instance.damage);
hitObjects.Add(other.gameObject);
}
}
where I would like to have the opponent's collider later, I have already inserted "other"
Make the projectile a game object with a child particle system that gets triggered once the projectile hits a target
I have a problem with physics. It is my first time doing in 3D, so it may be just a beginner mistake.
I just wanted to create a simple player controller and make it so that it can not pass trough cubes.
The problem is that when going straight into the cube, part of the player is in the cube itself. When stop moving, it pushes me, so they are not intersecting (that makes sense).
I tried moving the player using .Transalte, .MovePosition and by changing the velocity of rigidbody itself. None of it change anything. The player can always move a part of him into the cube.
Any ideas how to solve this?
My player controller:
(The 2 lines commented out in Move() are just other ways to move the player.)
using UnityEngine;
public class PlayerController : MonoBehaviour
{
[SerializeField]
private float movementSpeed;
private Vector3 input;
private void Update()
{
GetInput();
}
private void FixedUpdate()
{
Move();
}
private void GetInput()
{
float inputHorizontal = Input.GetAxisRaw("Horizontal");
float intputVertical = Input.GetAxisRaw("Vertical");
input = Vector3.ClampMagnitude(new Vector3(inputHorizontal, 0, intputVertical), 1);
}
private void Move()
{
GetComponent<Rigidbody>().velocity += input * movementSpeed;
//GetComponent<Rigidbody>().MovePosition(GetComponent<Rigidbody>().position + input * movementSpeed * Time.deltaTime);
//transform.Translate(input * movementSpeed * Time.deltaTime, Space.World);
}
}
Player is standing still
Player is moving towards cube
Settings of the Game Objects itself
Now I think I understand your problem.
The collider is a geometric shape that is checked but the outcome wont take place until the collision has actually taken place, this means, one geometric shape being inside the other. By this I mean, that what you are experiencing is the normal behaviour of the collision. If both elemnts are rigid bodies, both will move and your problem wont be perceivable, but if your cube is not a rigid body or is kinematic, will stand still in the same position, and depending on the other object speed, its normal that an invasion/superposition of the elements is perceivable, because that is the frame were the collision took place, and were your element needs to be moved back because it has collided.
Consider that if the speed is high enough, and the position from one frame to another varies enough, the collision might not even take place, because the geometric parts do not interfere between frames, as the position variation might be bigger than the bounds of the collider itself. The collision check at the end of the day, is dicrete, and not continuous (even you can set it as continuous to be as frecuent as possible).
To solve or improve that, you can adjust the speeds to avoid that being perceivable + adjust your collider to make it react before the graphic superposition occurs. This means making the capsule or the cube collider bigger than the graphic element itself. You can even calculate , to make it as bigger as much as your your speed * Time.deltaTime result or speed * FixedTimeStep result, depending on your safety distance needs. I think one of those should be the safety distance you need to take into account before the graphic collision occurs.
Another thing you can do is tight more the times physics calculations are done.
https://docs.unity3d.com/Manual/class-TimeManager.html
But need to be careful with this as this can be a performance devourer and need to be handled with care. You can make some trials with that and check your problem can improve.
Hope that helps
You can increase the scale of your player's collider from the Collider component attached to it. You can check how big the collider is from the editor scene view.
Edit: The issue might be that your movement or collision code is called in Update instead of FixedUpdate. When working with rigidbodies, you want to call the physics calculations inside FixedUpdate.
remove rigidbody from the cube, you can click on 'Gizmos' in the top right of the editor and make sure the colliders are at the edges of the objects.
I am a beginner and trying to make penalty shooter Game in unity.. I have just setup the scene and just trying to shoot the ball towards the goal post.
When i shoot the ball it goes toward the goal but does not come down, because i am shooting it through the script and its gravity is off and kinematic is on.
Currently i have the following script:
void Start () {
startTime = Time.time;
rb.GetComponent<Rigidbody>();
}
void Update () {
transform.position -= fakevel * Time.deltaTime;
transform.position += fakeGravity * Time.deltaTime;
fakevel *= 0.999f ;
}
void OnTriggerEnter( Collider other ) {
fakevel = new Vector3(0.01f, 0, 0) * 2000f;
fakeGravity = new Vector3 (0 ,0.01f, 0)* 200f;
y = -45.68312f;
}
}
I have tried enabling the gravity and disabling the kinematic at some specific position but i does so the gravity just pull it down at that position and it does not look realistic. Some screen shoots are attached.
Please help me in setting trajectory of the ball and stopping it when it collides with the goalpost,
I would suggest you use a non-kinematic rigidbody on your ball and add a force to it when you shoot it: GetComponent<Rigidbody>().AddForce(forceVector3, ForceMode.Impulse) (this is just an example, you should avoid calling GetComponent on a frequent basis, you are better off calling it for the rigidbody component once on Start and store it in a private variable)
This way Unity's physics engine can handle gravity and the balls' velocity over time. To modify the trajectory you can play around with the properties of the balls' rigidbody component.
If you want to have more control over the velocity, you can also set the rigidbody's velocity directly in the FixedUpdate() (which is called right before each physics update). When doing so, you have to consider that velocity is measured in m/s and the physics engine handles sub-steps for you (I am assuming that FixedUpdate() is called more than once per second), meaning you do not have to multiply your velocity with some delta time (but I am not 100% sure about this right now).
Seeing how it does work, just doesn't give the effect you want, you can either spend several hours fine tuning it, or like xyLe_ stated, use the built in physics. Using the built-in physics isn't a bad thing, you just gotta be smart with it. You can add a bouncy physics material also, which will help give the ball a well, ball feel.
So im creating a simple game and one component of the game is a greendot following the outside of the level. I got this working using a raycast in the middle which rotates and gives the position of collision the the gameobject.
game overview
The problem is that the speed is inconsistant at the moment since the distance between two collisions can be further distance if i have a slope. I also have the feeling that there should be a easier way to get the same result. What are your thoughts?
public class FollowPath : MonoBehaviour {
Vector3 collisionPos;
public GameObject greenDot;
void Update ()
{
RaycastHit2D hit = Physics2D.Raycast(transform.position, transform.up);
transform.Rotate(0.0f, 0.0f, 3);
if (hit.collider != null)
{
collisionPos = hit.point;
}
greenDot.transform.position = collisionPos;
}
}
I'm not sure if you will like this answer, as it suggests a complete departure from the way you were trying to do it.
A simple way to do this, would be to give your moving dot GameObject a Rigidbody2D component, AND a CircleCollider component.
Then, make your walls, and add to each an EdgeCollider component.
You'll probably also want to add a PhysicsMaterial2d to each GameObject with a Collider and set the friction and bounciness values for each.
Once this is setup, you can apply an initial force to the rigid body ball to get it moving, and it will bounce off the walls just like a ball does, using the Unity physics engine. No code would be needed in you update functions.