I want to know how the Box Collider works in Unity. I have read all of the Unity documentation and PhysX documentation but there are not any detailed explanations as to exactly how they work (possibly because it's confidential IP).
How does a box collider know when it is intersecting/overlapping another box collider?
What metric is actually measured to know when a collision has taken place? Does it look to see if there is a point or vertex in the box collider is inside the volume of another collider? If so how does it know that a vertex is within the volume of another collider?
What are box colliders made from? Is it lots of small objects put together or is it one big object?
Thanks for your help in advance
Related
As you can see in the included video the player falls over the floortile till the outer edge of the floor. Instead it should stop at the inner edge of the tile so it looks like its standing ontop of the tile. Can anyone help? I cant find anything on the internet regarding my issue.
Im sorry if this is a easy fix. Im a beginner. This for a school project :)
Video: https://streamable.com/99jz2o
enter image description here
Photo of sprite standing on the wrong edge of the tile.
Edit: I went back to the tile palette and redrew the level. This time selecting the game object + bitmap again. Now it works. Probably the reason why it didn't work was that when I drew the level I had not added Tilemap Collider 2D and Composite Collider 2D. Now redrawing with those 2 components added it works as it should!
The problem is with your tile map collider. Instead of using this, set empty game objects as children of the objects that make up the . Then, add BoxCollider2Ds to each one, and add scale them to fit the map. If that doesn’t work, then it is either a problem with the rigidbody, or the box collider, make sure that all of the settings are set to default, then slowly change them back, and you will discover what is causing the problem. Then you can comment on this post what variable changed it.
Your issue is the Composite Collider. The docs specify that they
do not define an inherent shape. Instead, it merges the shapes of any
Box Collider 2D or Polygon Collider 2D that you set it up to use
When you attach a BoxCollider2D or PolygonCollider2D, there is a check box on them that specifies Used by Composite. When checking this box, other fields will disappear as they are now controlled by the CompositeCollider.
To use this collider, make a new object that will hold all your other colliders or make a few that hold sections of your map. Give this new parent object a CompositeCollider2D and give all the children BoxCollider2D or PolygonCollider2D. After this, make sure to check the box Used by Composite on the children Colliders.
Edit: Sorry just saw you were using a Tilemap. Just make the CompositeCollider a parent of your Tilemap while keeping the Used by Composite checked.
Edit 2: I am not too familiar with Tilemaps with Composite Colliders, but one other solution you can try before re-childing is changing the Geometry Type field on your CompositeCollider from Polygons to Outlines.
I am trying to hit a ball using a golf club. My golf club has three components (three game objects: handle, shaft and head as shown in the first attached image). Head gameobject's inspector can be seen in the another attached image.
To hit the golf ball, we need a collider. So I put a Capsule Collider at head game object. But I don't see any collider at head gameobject.
The head is shown in the last image.
Why I can't put Capsule Collider at the object?
EDIT:
Thanks for the reply.
I increased the radius but still the same.
I placed a Quad in the scene and put Mesh collider onto it (called AW52Collider). Please see in the
first image. We can see the collider clearly.
But I did the same thing to Club head, as it is also a game object I should be able to put a Mesh collider. But I don't see anything. Why?
Please see in the second image.
One more thing I don't understand is when I put AW52Collider inside Club Head object, I don't see AW52Collider also. Why? Please see in the third image.
Increase the size of your collider, those values do not look like you should see the gizmos at all. Best would be to reset the collider to its default values and then play with them until you are happy.
It is best practice to create a child object with colliders on it. The reason is the placement of the collider. The collider is always centered around the pivot point of a GameObject. But you probably want to move your collider freely or disable a group of colliders manually for testing (or optimization) purposes. Also consider that an object with multiple small colliders as child objects is considered one big collider (rigidbody wise). Source (Compound Colliders)
Just enable Gizmos button and you'll find your capsule collider.
See this picture to know exactly where to find it:
(It's in the toolbar below the Scene tab)
I'm having some troubles checking the "Is Trigger" option on a non-convex mesh collider.
I looked for an answer on the internet and found something like :
Unity 5 does not support that because the updated PhysX does not allow it.
(https://forum.unity3d.com/threads/how-to-enable-trigger-on-a-mesh-collider.347428/)
I was wondering if there was a solution now? Since the post is kind of outdated?
I hope you'll be able to help me :P
Thank you in advance,
Axel
A mesh collider can collide with a primitive collider (box, sphere, capsule) but there is no way to have two mesh colliders register a trigger or collision.
You'll need to use compound colliders to approximate the shape. IMO although it seems imprecise at first in practice you hardly notice if your collision area is slightly outside of your mesh. Performance wise multiple primitives (on anything other than mobile at least) are next to nothing so don't be afraid to use as many colliders as you need to approximate your shape.
I'm having a weird problem. I just downloaded an object model from the internet which is a garbage can, and I inserted it into Unity.
It seems to ave no collider! I also added Box Collider but again it does not work too, and I can go through the object!
Here's the image of project and the object with its components. Can you please tell me what's going on?
Hy,
The cube collider is useless.
Your mesh collider don't work because there is no mesh on your object.
The mesh must be on a child of this element.
Sorry for my bad english i'm french.
I'm quite new to UnityScript as my area of interest is python, however me and a friend are planning to create a small indie game and I need the skybox to change on collision in unity. I would prefer this to be done in javascript if at all possible. Please take a look at it and let me know whats wrong with it, as when run it makes no difference to the scene.
#pragma strict
var mat:Material;
function OnTriggerEnter(trigger: Collider){
RenderSettings.skybox=mat;
}
That is the entire script. Thank you for any help given
make sure that for your objects that collide... typically one must have a static collider (e.g. floor, wall) and the other a collider and rigidBody to hit it (e.g. player, car). Also check your physics settings to make sure the layers that the objects are in, can hit each other.
Make sure you have your script on the right object... collider or collidee ? try putting a script on both objects with a print in each.
Check here for more info
http://docs.unity3d.com/Documentation/Manual/Physics.html
What exactly to you mean by changing on collision? Skyboxes cannot be collided with. If you mean objects colliding other than the skybox, make sure that at least one of the collider's has "Is Trigger" checked in the inspector.