Raycast passing through box collider when trigger is enabled for object - unity3d

I'm setting up footstep sounds in a 3rd person game. All works fine, except getting water collision to work correctly. I setup a simple box collider where the top of the box is on the surface of the water and the bottom of the box is below the terrain and water. However, when I set the collider to a trigger the player passes through the collider (correct) but the raycast also skips the collider and hits the next object which is the terrain (raycast is checked on in settings to collide with triggers..). of course if i turn off the trigger the player walks on the box collider, which is not what I want. The transfer.position is the in chest of the player model. the water comes up to the model's waist. Any help is appreciated. Thanks.
void Update () {
RaycastHit hit;
if (Physics.Raycast(transform.position, Vector3.down, out hit))
{
Debug.Log(hit.collider.tag);
}
}

Ideas to try:
1) Check Edit->Project Settings->Physics, make sure Raycasts Hit Triggers is checked (looks like you already did, thumbs up).
2) Make sure that your trigger is not on the Ignore Raycast layer.
3) Make your trigger thicker/wider.
4) Give your Raycast call an explicit layer mask and make sure your trigger is on that layer.
5) Make sure your trigger component is actually enabled when the call goes through.
6) Try the other *cast methods... Collider.Raycast, Physics.Spherecast, etc.
7) Solve it a different way, like using another Collider specifically for this purpose on your character object, and using OnTriggerEnter or collision events.
8) I vaguely recall having a similar problem a long time ago, and the solution involved putting a dummy RigidBody on the trigger object... something about Triggers getting filtered out in certain cases when no RigidBody is attached.
Hope that helps!

Related

In Unity 2D, how do I achieve Non-trigger collsion that doesn't "physically" move the rigidbodies?

I have a bullet game object and an enemy game object.
I want to have the ability of getting the collision point/contact, which's why I think I need the collider of the bullet to not be a trigger collider - this way, I want to have the bullet bounce off the enemy. At times, the bullet will need to bounce off of rectangular objects (not a problem), but I also want the bullet to bounce off of elliptic objects (the problem).
I want the bullet not to "physically" push the enemy, which is why, intuitively, I should set the bullet's collider to be a trigger collider.
When the bullet's collider is a trigger collider, I seemingly don't have a way to implement the bouncing.
But when the collider's not a trigger collider, it pushes the enemy object.
There's no code errors, but I think the code hasn't got anything to do with the problem.
I suspect the problem may have something to do with the Physics Collision Matrix.
EDIT
It seems that raycasting would be the solution to the problem, as Leoverload proposed. My problem became a different problem now, so I'll close off this thread, and open a new one.
Thanks for the help, #Leoverload ! :D
For the position of the hit it's very easy. You must have 2 colliders and 2 Rigidbody and then you can simply add a
Void OnTriggerEnter2D(Collision Coll) and inside it check for the tag : if(coll.compareTag("surface")) and inside you can get the position with collision.transform.position.
The collision matrix on the Physics menu only allows to remove Collision between certain layers, it's useful if you want the enemies not to push eachother!
If you don't want the player pushed you can change the collider to trigger, and destroy the bullet just after the collision with the same method as before with a void OnTriggerEnter2D and the compareTag. In this way it will look like it touches the enemy and explode, but it won't actually touch anything. If you want to add knockback to the player then you could do a simple AddForce based on the direction of the bullet and the work is done!
If you want to avoid the bullet to move walls you can set walls to static and it should work fine

Unity Making a prefab collide with surroundings, but not other objects of the same prefab

The picture below is my simulation, and the problem im facing is that they wont collide they way i want to.
I made them move randomly and i want this behavior.
The green balls are supposed to "bounce" off the outer grey walls, so collide with them (simulate physics)
The green balls are NOT supposed to bounce of each other, but only do triggerevents (so i know when they are on top of each other)
How do i do this. I have looked at multiple tutorials and i simply dont know what to do. As far as i understand, to make a collision, one of the objects has to have a rigidbody on, and the other a normal collider?
I have to tried to follow this overview. The balls are from the same prefab, so to get a trigger for them i have to pick either
static trigger collider, rigidbody collider trigger, or kinematic rigidbody trigger collider (as seem from the overview).
BUT if i pick any of those i cant get a collision with the walls? Do i have to do the wall collisions myself?
What you can do is make all the walls static colliders, and make a script on all the balls that check whether they hit a wall or a ball. and do actions that way.
Or
Make the walls check for a collision with the ball and add a force to the negative direction that they came from or something.(up to you how you want the balls to behave)
for example :
OnTriggerEnter(collision other)
if(other.transform.tag == Ball)
//Run Some Code here
// for example
BallRb other.GetComponent<RigidBody>();
BalRb.addForce //add the force that you want.

Unity composite collider 2d - Collission detection with onTriggerEnter or Raycast

I have found other people asking for this on the internet but I haven´t found a solution. I have a 2d game using tilemaps and composite collider. But when I add a composite collider I can´t use ontriggerenter or raycasts to detect the ground. So I have completely removed the ability to jump because there is no way of knowing if the player is on the ground or not, resulting in the ability to jump again before landing. Has anyone found a way around this?
There shouldn't be any issues with your approach. Without code examples all I can give you is some general pointers:
OnTriggerEnter
Use OnTriggerEnter2D(Collider2D col) to detect Trigger enters in a 2D environment.
OnTriggerExit2D for leaving, OnTriggerStay2D for every frame you're still colliding with other colliders.
Don't forget that one of the objects need to have a Rigidbody2D (if you don't want to use physics, select "Kinematic" in the dropdown and check the "Use Full Kinematic Contacts". For improved collision detection, change the Collision dropdown to "Continuous".
Raycast
When using Raycasts you need to, either start the raycast from a position that doesn't include your own hitboxes, or make sure the raycast ignore its own layer.
// Raycast down ignoring Player layer
int layerMask =~ LayerMask.GetMask("Player");
RaycastHit2D hit = Physics2D.Raycast(transform.position,
Vector2.down,
layerMask: layerMask);

Using triggers attached to enemy to make enemy jump in a 2.5d platformer

so I've got an enemy in my 2.5d platformer, that I already got to follow the player around, now I want him to jump over small obstacles, and honestly, I have no idea how to. My enemy is a sphere with rigidbody and a box collider scaled 2x in X axis, effectively making it 2 times wider than the sphere. I want this box collider to be a trigger and for it to launch a AddForce.
Where do I put the code for the trigger - if I put it in void update() wouldn't it apply force until the sphere is above the obstacle? I only want it to apply the force once.
Also, what would the code for the trigger look like?
So far I only got figured out how to find the rigidbody by getcomponent and apply force to it, and I watched a video on triggers, but it didn't really help :/
Use OnTriggerEnter method like this:
void OnTriggerEnter(Collider other)
{
if (other.tag == "IMakeEnemyJumpBeforeAnObstacle")
{
// add force here
}
}
Note: this code should be in your enemy script. Plus use IMakeEnemyJumpBeforeAnObstacle tag on the trigger object which will be placed right before the obstacle. And make sure both the enemy and the other object have property IsTrigger checked from inspector.
Learn More
Hope this helps

Raytracing not responding correctly

So I'm new to Unity and I'm sure I'm missing an easy step, but after looking online for a while for some reason I can't find the solution.
I have two objects on the screen, player and enemy. Both have Rigidbody2D, and Box Collider 2D attached. On Box Collider 2D I have clicked is triggered On Rigidbody2D for both I have clicked Is Kinematic. On player I have a simple movement script. On the enemy object I have this:
void Update () {
RaycastHit2D hit = Physics2D.Raycast(transform.localPosition,transform.right,Mathf.Infinity);
Debug.DrawRay(transform.localPosition,transform.right);
if (hit)
Debug.Log(hit.collider);
}
Now for some reason when I move player over the object if (hit)
is true, but if I move the player anywhere on the right side it is not true. What would be the reason for this? Thanks.
First of all you don't need Rigidbody for raycast detection, only colliders. Second, Physics2D.Raycast uses world position, not local, so replace "transform.localPosition" with "transform.position", this messes it up a lot if the transform is child of something. Take in mind that you are sending raycast from the right side of your transform, so maybe it's not hitting anything and values you are getting are actually correct.