Best way to "highlight" an object on mouse over

Questions & Answers
1

Lets say I have like 25 different objects in the scene which are always visible for the camera with quite complex colliders. I then want to highlight whatever object im hovering hover(with the mouse) by changing the texture or whatever. Which is the best way to do this?..I guess I could send out raycasts every frame and change the texture whenever it hits something, but that seems quite expensive?, is there any other way?

3

This will be attached to all the things that can be higlighted with hovering.

private Color startcolor;
void OnMouseEnter()
{
    startcolor = renderer.material.color;
    renderer.material.color = Color.yellow;
}
void OnMouseExit()
{
    renderer.material.color = startcolor;
}
4

Okay so your problem with OnMouseEnter and Exit is that you are setting yourself up to be confused if you are porting to a VR platform, or a platform that has a pointer controller. If you want to keep your project open ended and not only have it releasable for PC, you can do something like below:

Create a main game object that doesn’t get destroyed so that you have a scene manager object between scenes. Make a main game script, we will prtend it’s called “MainGameScript.cs” and it’s class name is ‘MainGameScript’ and put this inside of it, above it’s class:

[System.Serializable]
public class MainInput_Ray { 
public Ray ray = new Ray ();
public RaycastHit hit;
public bool hittingSomething { get; set; }
}

Then goes in your main game script’s start:

public MG_Ray mainInput_Ray;

Start() { 
    mainInput_Ray = new MainInput_Ray();
}

…and then this goes in your main game script’s update AFTER the scene is fully loaded and playing:

Update() { 
    mainInput_Ray.ray = MG_Camera.GetComponent<Camera> ().ScreenPointToRay (Input.mousePosition);
mainInput_Ray.hittingSomething = Physics.Raycast (mainInput_Ray.ray, out mainInput_Ray.hit, 1000);
}

Now in your object’s script you can go like:

private MainGameScript mainGameScript;

Start() { 
    mainGameScript = GameObject.Find("MainGameScript"); //gameobject find is okay if it's in your start method
   //make sure you set your main game script's script execution order to FIRST
}

Update() { 
    if (mainGameScript.mainInput_Ray.hittingSomething && (mainGameScript.mainInput_Ray.hit.transform == this.transform.parent.transform)) {
 
   }
}

Then throughout your entire project whenever you need to check if something is hit you do mainInput_Ray.hittingSomething == true???, check the results, throw an && in the if statement, just make sure the scene if fully loaded. Personally I have a state machine in my main game object that handles the loading screen, saving and loading of data and has a ‘SceneActive’ state I check against first.

Now if you have a VR controller you just have to replace this part:

        mainInput_Ray.ray = MG_Camera.GetComponent<Camera> ().ScreenPointToRay (Input.mousePosition);

This code is optimized just like OnMouseEnter, because you aren’t creating a new ray all together each and every frame, there is only one global ray you check against.

5

I’m updating the answer since a lot of links trace to this post despite it being depreciated.

private Color startcolor;
    void OnMouseEnter()
    {
        startcolor = GetComponent<Renderer>().material.color;
        GetComponent<Renderer>().material.color
= Color.red;
    }
    void OnMouseExit()
    {
        GetComponent<Renderer>().material.color
= startcolor;
    }
2

function OnMouseEnter?