Code to check if sprite is within screen bounds (3D UI)

[toyob]

Hi ArenMook,

I have to keep a lot of live UISprites during the game, and most of them are situated off-screen.

I am looking for a way to improve performance, by putting a script onto each UISprite containing object. Idea is to disable the UISprite when it's off-screen (completely) and re-enable when some portion of a sprite becomes visible within the screen bounds. (Maybe there is a way to do it through the parent panel? I haven't found)

I tried many solutions but none of them worked. Please help! I am dumb and looking forward to some working code. I know it's a piece of cake for you. Thanks.

This is what I currently have (doesn't work, sets Visible all times)

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class CheckSpriteVisibility : MonoBehaviour {
6.  
7.         public UISprite thisSprite;
8.        
9.         void Start () {
10.                
11.                 thisSprite = this.GetComponent<UISprite>();
12.                
13.                 cam = Camera.main;
14.                 planes = GeometryUtility.CalculateFrustumPlanes(cam);
15.                
16.         }
17.        
18.         public const bool t = true;
19.         public const bool f = false;
20.        
21.         public Bounds b;
22.        
23.         Camera cam;
24.         Plane[] planes;
25.        
26.         public bool Visible;
27.        
28.         void Update () {
29.                
30.                 b = NGUIMath.CalculateRelativeWidgetBounds(this.transform);
31.                
32.          if (GeometryUtility.TestPlanesAABB(planes, b))
33.                  Visible = true;
34.          else
35.                  Visible = false;
36.        
37.                
38.         }
39. }
40.  

[ArenMook]

NGUI has this built in with clipped panels (used for scroll views). Enable clipping on the panel and set the panel's dimensions to the entire screen's dimensions. That said, I don't really see what you will get out of this. Things that are off-screen don't do anything to affect the fillrate as the triangles get culled by the GPU.

Last but not least, the easiest thing to do is to handle it manually -- you know when you move something off-screen (usually an entire window = panel), when doing so you can just disable its game object until you need it. The free Starlink UI kit on the asset store has a window management system built-in that handles showing one window at a time and keeps track of navigation for things like "go back" functionality that you may also find useful.