Resolved Is there a way to call the function of the object hit by RayCast without using GetComponent?

hello

I want to fire a RayCast on the screen and run a script on the hit object.

But the way I thought was to keep calling GetComponent with Update.
Calling GetComponent repeatedly is not good for optimization, so I want to use another method.
-
So it seems that OnMouseOver can also be used for 3D objects, so I tried that too, but it didn't seem to work,
so I gave up.


Is there a way to call the script attached to the hit object without using GetCompent?

Code (CSharp):

1.     private RaycastHit hit;
2.     private float maxDistance = 300f;
3.  
4.     private void Update()
5.     {
6.         if (Physics.Raycast(transform.position, transform.forward, out hit, maxDistance))
7.         {
8.             if (hit.collider.GetComponent<ValueInfo>())
9.             {
10.                 hit.collider.GetComponent<ValueInfo>().OnValue();//I don't want GetCompent to be called on Update......
11.             }
12.         }
13.     }

 

One script running

GetComponent<T>

maybe once per frame isn't going to affect performance. Always use the profiler to determine where your performance issues are.

Also don't forget

TryGetComponent(out T)

exists.

The monobehaviour callbacks only work with the old input system. With the new system you need to use the Event system interfaces like these: https://docs.unity3d.com/Packages/c...Engine.EventSystems.IPointerEnterHandler.html

Otherwise, via raycasts, you will have to use

GetComponent<T>

. That's just a fundamental principle of Unity.

 

In practice, GetComponent is WAY less of a hit than other searches like FindObjects. Even if it's not optimized, you're doing, what, 2 to 20 Type.Equals() calls, and you're done. If you know you'll need to do it often, move the types you want to GetComponent higher in the object's component list.

 

thank you
You are truly an angel!


I used IPointerEnterHandler
Then, I added the [Physics Raycaster] component to the Camera, and masked the Layer with the Canvas.

so it works fine
Thank you very much.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.EventSystems;
5.  
6. public class MouseOverInfo : MonoBehaviour, IPointerEnterHandler
7. {
8.     public void OnPointerEnter(PointerEventData pointerEventData)
9.     {
10.         Debug.Log("Name:"+gameObject.name);
11.     }
12. }
13.  

 

OnPointerEnter will still rely un an underlying GetComponent<IPointerEnterHandler>() after a raycast (done by the engine internally). So you're not going to be gaining any performance.

 

Agreed.

And depending on the system, it's probably better to be happening all in once place (ergo, one system raycasting each frame) rather than written across a bunch of components.

 

I didn't know that OnPointerEnter also checks with GetComponent.

It would be easier to proceed by checking with TryGetComponent(out T) in the existing code.

Thanks for letting me know how to do it.

 

How else would it know that it hit an IPointerEventHandler?
A Raycast is always done against colliders, so its result will always be a collider. Anything after that will involve GetComponent and/or casting.

 

I tried to use TryGetComponent(out T) in the if statement part of this code

Code (CSharp):

1.     private RaycastHit hit;
2.     private float maxDistance = 300f;
3.     private void Update()
4.     {
5.         if (Physics.Raycast(transform.position, transform.forward, out hit, maxDistance))
6.         {
7.             if (hit.collider.GetComponent<ValueInfo>())//change here
8.             {
9.                 hit.collider.GetComponent<ValueInfo>().OnValue();
10.             }
11.         }
12.     }

OnPointerEnter also depends on GetComponent<IPointerEnterHandler>(), so
I understood that the degree of optimization of the method of writing code to determine by Raycast in Update() and the method of using OnPointerEnter is similar.

 

And? Did it not work?

It'd just look like this:

Code (CSharp):

1. if (hit.collider.TryGetComponent(out ValueInfo valueInfo))
2. {
3.     valueInfo.OnValue();
4. }

It also most likely doesn't matter. Don't speculate on potential performance issues. 99.99% chance it won't ever be an issue.

The only real concern here is an design/architectural one.

 

one (messy) alternative:
caching the getcomponent for object(s) at start or at first raycast detection,
into some dictionary/hashset, by object name or so (if set to uniques)..

 

Code (CSharp):

1.     private RaycastHit hit;
2.     private Ray ray;
3.  
4.     private void Update()
5.     {
6.         ray = Camera.main.ScreenPointToRay(Input.mousePosition);
7.  
8.         if (Physics.Raycast(ray, out hit))
9.         {
10.             if (hit.collider.TryGetComponent(out MeshInfo meshInfo))
11.             {
12.                 meshInfo.PlayValue();
13.             }
14.         }
15.     }

I wrote hit.collider.TryGetComponent and it works fine.

thank you!

 

i think a fair balance between optimization and cleanliness could be to cache only the last collider detected and its corresponding component. This avoids most of the unnecesary computations (i.e. mouse remaining on the same collider for a while).

As mentioned, check the profiler to understand if and what to optimize.

 

I got exactly into same problem I hit a gameObject with a raycast.
Then I need to run the script withing the object but all I have is just the gameObject reference or name...
To run the script in this gameObject I need to use getComponent.
I have many possible objects being hit with the raycast, so I could possibly build an array of the script references, but then I need to search trough them to see which one got hit by name...
At least if I can extract the object index in the array from this raycast I could maybe build an array of the scripts, but for this I still need to get the script...

Using sendMessage is I think slower than getComponent...
I think in this situation the fastest solution will be to use the getComponent.

I think maybe to avoid the getComponent there would have to be an update to the raycastHit to contain a custom data...

 

You should never have to search for anything by name. RaycastAll for all the results, run down the collection and TryGetComponent on each element and call the necessary method. This method could be composed via an interface too. You can use LayerMasks to ensure you're iterating through the smallest number of objects.

Don't speculate on what is more performant. Use the profiler if you have a performance issue.