I'm doing a platformer and I have colliders and rigid bodies in my hero and my enemies. I have also colliders on my platforms.
Everything works and moves nice, dudes move along the platforms, they jump and they catch each other.
I use the collider in my enemies to discover if the hero touches them and then deal damage to the hero. And when slashing I use "overlapCicle" to discover if the sword touched the enemies.
My problem is that with this setup my hero and my enemies can walk one in the top of others. Additionally if I disable the collider of an enemy (to make it invulnerable for a second after being hit) it will fall through the platform..
What's the best approach to this structure of colliders? I want everybody to walk over platforms. I want enemies colliders to detect the hero touching them and I want my sword (overlapcircle) to find enemies. And I want hero and enemies to be able to walk across each other, specially enemies.. they should not walk one over the others
Seems like you want the enemy and the player to be able to walk through each other, while being able to interact with each other.
In that case, you can create another physics layer for your interactions (attacking or vision detection), and set-up your Physics layers to ensure that the Player and Enemy do not collide, but their interaction layers can collide with the respective characters.
Like so:
Where PlayerTriggers and EnemyTriggers will be physics layer for interaction between the enemy/player.
This ensures that the enemy's vision/attack collider can hit the player, but the enemy itself can't do so. Vice versa.
To access the physics layer menu, go to Edit (Top left) and click on Project Settings.
You can read more about it in Unity's Doc.
Related
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
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.
I am making a 2D platformer type of game. In this platformer there are both the player and "enemies". The problem arises because: I need both enemies and players to collide with the ground so they don't fall through it. I need to detect when a player collides with an enemy so i can register damage. I need the player to be able to walk through an enemy. Having colliders on the feet is not an option because the player may interact with it. What is the best way to approach this kind of specific collision detection?
You can use the Layer Collision Matrix (Edit -> ProjectSettings -> Physics2D) to define exactly which layers can collide with which other layers.
So I would simply use two colliders on the player:
one is not a trigger so it can collide with the ground. Put this on a layer playerGround which collides with the ground layer.
the other one is a trigger and can collide with the enemy layer. Name it e.g. playerEnemy or something.
Since each GameObject can only have one layer your colliders would have to sit on different objects e.g. like
player (Rigidbody2D)
|--GroundCollider(layer: playerGround)
|--EnemyCollider(layer:playerEnemy, isTrigger)
The enemy layer can collide with both the ground and the playerEnemy.
This way both can walk on the ground. Player can walk through enemies but you can use OnTriggerEnter to detect the collisions with enemies.
Currently I'm making a racing game.
I move my cars with the Transform.translate class.
Now the thing I want for my cars is not to move through each other.
I attach colliders and a RigidBody to my player car and it's working.
But my problem is that each time my CPU cars and player car encounter with each other, my player car shows unrealistic behavior like moving out of the screen or throwing away.
I know this is part of the physics engine behavior but is there a way to make the RigidBody only do one job and make objects not to move through each other not to add other physics behavior?
Any ideas?
There are just few problems:
1.You don't move Rigidbody with transform.translate. When you do this, colliders will go through other colliders.
You move Rigidbody with Rigidbody.AddForce, Rigidbody.velocity and Rigidbody.MovePosition. By moving Rigidbody with these methods, collision should be functioning properly.
2.You are not even supposed to move the Rigidbody of the car.
Use WheelCollider. There are many online tutorials on how to set them up on the internet but Unity's documentation is fine too.
WheelCollider.motorTorque is used to move the car forward or backwards.
WheelCollider.steerAngle is used to steer the car.
WheelCollider.brakeTorque is used to brake the car.
If you need further help, you can find a fully working WheelCollider samples here.
I have a Unity project in which there is a 2D game world that consists of static colliders to make the geometry solid to the characters that inhabit it. The player is a dynamic collider (with a non-kinematic rigidbody). There's also an enemy character that is also a dynamic collider. Both characters walk over the floor and bump into walls like I'd expect them to.
What I want to achieve is that the player and enemy are not solid to each other, so they can move through each other. I achieved this by putting the enemy and the player on separate layers and setting the collision matrix so that these layers do not collide with each other. The problem I'm having now, however, is that I do want to detect whether or not the enemy and the player ran into each other. I added a trigger collider to the enemy character, it's on the enemy layer which means it doesn't detect collisions with the player.
I thought of making a sub-gameobject for the enemy, put it on the player's layer, add a rigidbody and trigger collider to it and use that to detect collisions between the player and the enemy, but it feels so convoluted that it leaves me wondering if there isn't a more elegant solution for this.
Edit (2020-05-26): Nowadays you can tell the engine to ignore collisions between two given objects. Kudos to Deepscorn for the comment. Will leave the rest of the answer unchanged, and read with that in mind.
Yes, you need to create a child GameObject, with a trigger collider, and put it in a layer that interacts with the player layer.
No, you don't need to add a Rigidbody to the new GameObject, the parent's rigidbody already makes it a dynamic collider, so you will get OnTrigger events.
As a side note, just to keep things organized, if you create a child of the enemy don't put it in the player layer. For example, in the future you might need to disable the player's layer collision with itself. Furthermore, if your player interacts this way with many objects, I'd put a single trigger on the player instead of the enemies, on a separate PlayerTrigger layer, just to keep things simple.
Isn't there a simpler way? Not really. You definitely need non-interaction between the player and enemy colliders, but some kind of interaction between them too. So one of them needs to span two layers, or the whole interaction would be described by a single bool. The physics engine processes lots of information in one go, so you can set all the layers and collisions you want, but during the physics loop you have no further control on what happens. You can't tell the engine to ignore collisions between just two objects. Having only 32 layers, and having them behave in the rigid way they do are actually heavy optimizations. If you are concerned about performance for creating another layer, disable interaction between layers you don't need, like the trigger layer and the floor and walls, or layers that don't even touch.
Your alternative is doing it all by code, which is even less elegant. A single child capsule on the player doesn't sound that bad now, doesn't it?