Unity 2D How to get Object that is being overlapped - c#

I have blocks in a scene and I move a block with the mouse. Each block has a BoxCollider2D attached. I am trying to figure out which block it is that I bumped into. I can't use Rigidbody to detect collisions as I don't want any physics applied. I know how to detect if the object I am moving is overlapping a point but I don't know how to get the object that I am overlapping?

You don't need physics/rigidbody to use colliders; just set the colliders as triggers and use the OnTrigger method.

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Unity3D Rigidbodies acts like objects is elastic and falling inside eachother

I was making a game about stacking objects on top of eachother but when I spawn a new object above it falls inside in other object and behaves like elastic material.
I didn't specify any Physics Material to the Rigidbody, It's just a vanilla Rigidbody component.
Here is a gif about my problem
You might have forgotten to add a Box collider to the cube prefab.
Make sure that the collision detection method on the rigidbody is set to either continuous or continuous dynamic. Make sure there's a collider as well.

Making an object move through another and keep going?

I am currently making a sidescrolling game in Unity 2D where an enemy rises up, and then dives down to the player, but then keeps going until it is off screen, like how this image shows. 1 I can get the enemy to collide with the player but I can't make it keeping in that direction until off screen. How would I be able to do this?
You have to make your collider to trigger (it's a checkbox on your collider)
That means your object will not be affected by physics when it touch another collider, but it can calls functions.
You have to replace OnCollisionEnter/OnCollisionEnter2D, etc by OnTriggerEnter/OnTriggerEnter2D, etc.
Be careful, the parameter of the function may change too (Collision/Collider).

Unity Rigidbody has velocity but not moving

I have a game in Unity where cubes are repeatedly moved past the camera. I move the cube using a script where I set its Rigidbody's velocity each update. Once it moves out of view my script instantiates a new cube on the other side which begins the process again.
Recently I've found that it works fine for a random amount of cubes before, seemingly randomly, a cube is instantiated that does not move. Using the inspector I can see that this object has velocity. If I move it even a small amount using the editor it starts to move as normal.
Has anyone seen something like this before?
I'm fairly certain the problem was related to the fact I was trying to directly modify the velocity( The physics engine decided the object was at rest and stopped it moving. ). By setting the object to be kinematic and modifying its position in my code I solved the problem.
May be you are changing the velocity of your gameObject when it goes through a specific coordinate (in an if statement for example), unity is not very accurate sometimes with coordinates so it may be happening that the condition is never met. Change that condition and add a margin range to solve this error.

How to make my button change on collision

Hey I am trying to make my sprite button go from green to red and backwards when my player collides with it. I have a boxcollider2d as is trigger, and a script
script : https://gyazo.com/ec64a2bca5b23526c6949bf18cb50a0d
I think this is some of it but I dont get anything at all when colliding with the button can anyone enlighten me on this problem would be very appreciated.
Thanks in advance
It is important to distinguish the difference between Colliders and Triggers.
Colliders are used by the Physics system in order to make it so object do not penetrate or overlap each other. Triggers on the other hand are made so that you can check for overlapping areas, an example is a Ring in Sonic. Sonic collects the rings but they do not stop him from passing, think of these as triggers. If they were colliders sonic would jump into them and bounce off.
In Unity the process for creating a trigger is the same for creating a collider, with 1 additional step, and that is marking a check box.
As such it is also important to know which functions you should use in each case.
OnCollision... For Colliders, (Or Colliders not marked as triggers)
OnTrigger... for Triggers, (Marking a collider in unity as a trigger makes it a trigger.)
To just add a bit more detail, It is also important to use the correct collider types for the correct dimensions of the game, 2d Colliders/Triggers do not interact with 3d Colliders/Triggers. More so physics components: 2d Rigidbodies do not works with 3d colliders, and 3d rigidbodies do not work with 2d colliders/triggers.
As such there are functions for each 2d, 3d, collision, and trigger.
Another important factor is to ensure if you want to use these functions atleast one of the objects have to have a rigidbody of the correct type(2d or 3d).
As such the problem you were running into was using OnCollisionEnter2D for a "collider" that was marked as a trigger, in this case OnCollisionEnter2D is not called, but OnTriggerEnter2D is called.

How to animate rigidbody objects in Unity

I'm creating a game in which I need to move an object straight up, and when it hits another object they are connected with joint. That's why I need to have rigidbodies attached to both of them. The problem is that when I use animation to do this, collision is not detected, and unity tends to crash. Is there any proper way of "animating" rigidbody objects? Or maybe I should choose a different approach?
Set Rigidbody.isKinematic to true on the rigid bodies just before animating them. This will allow you to move (animate) the rigid bodies by changing the transform.position and other properties while allowing collisions with other non-kinematic bodies(rigid bodies with isKinematic set to false) and joint constraints to work properly. When the animation has completed and you want the bodies to be affected by physics again, set isKinematic to false.
Refer to the documentation for isKinematic for more information and a ragdoll example.

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