What is the best way to use the bounds of the camera in-world effectively?

I've actually already tried something like that, it didn't really work. I -think- what I want is Screen.width, but I keep getting ridiculously high values for the tiling limits with that.

For an Orthographic camera, the values are correct for the world units it sees. To verify, do the following:

• Start a new scene

• $$anonymous$$ove the camera's 'y' position to 0. The camera should be at (0,0,10).

• Set the camera to Orthographic.

• Put a cube in the scene at the origin.

• Size the cube to (10,10,1).

• Set the Orthographic size to 5.

You will see the cube's height exactly fills the frame.

Screen.width and Screen.height is the size of the screen in pixels.

Can you post your tiling code?

     void buildGround () {
         GameObject groundBase = new GameObject("BackgroundGround");
         
         
         
     
 
         for (int y = 0;  y < gridY; y++) {
             for (int x = 0; x < gridX; x++) {
                 Vector3 pos = new Vector3(x, -y, 0) * spacing;
                 Quaternion rot = new Quaternion(0,90,90,0);
                 GameObject groundpiece =    Instantiate(groundBackground, pos, rot) as GameObject;
                 groundpiece.transform.parent = groundBase.transform;
                 
             }
         }
         Vector3 screenPoint = Camera.main.ScreenToWorldPoint(new Vector3(0, Screen.height, 10));
         groundBase.transform.position = screenPoint;
     }

Once I've got my screen width/height, the idea will be to use the size of groundBackground, and divide in order to get a tiling limit that fits within the screen area, effectively dynamically altering gridY / gridX

Some comments:

• You should not build a Quaternion directly. The values are are not degrees. You should do:

  Quaternion rot = new Quaternion.Euler(0,90,90);

• The rotation makes me think you are trying to tile a built in plane. Note their default size is 10 x 10.

• Nothing here is scaling the game object that you place.

• I don't understanding what you are doing with the last two lines.

Here is a bit of code that tiles a sphere across the visible area:

 using UnityEngine;
 using System.Collections;
 
 public class Bug20 : $$anonymous$$onoBehaviour {
     
     void Start() {
         TileWithSpheres (12,9);
     }
     
     void TileWithSpheres(int numX, int numY) {
         float verticalSeen    = Camera.main.orthographicSize * 2.0f;
         float horizontalSeen = verticalSeen * Screen.width / Screen.height;
         
         float gridX = horizontalSeen / numX;
         float gridY = verticalSeen / numY;
         
         Vector3 v3Pos = new Vector3(-gridX * (numX - 1) / 2.0f, -(gridY)*(numY - 1) / 2.0f, 0.0f);
         for (int i = 0; i < numY; i++) {
             for (int j = 0; j < numX; j++) {
                 GameObject go = GameObject.CreatePrimitive(PrimitiveType.Sphere);
                 go.transform.position = v3Pos;
                 go.transform.localScale = new Vector3(gridX, gridY, 1.0f);
                 v3Pos.x += gridX;
             }
             v3Pos.y += gridY;
             v3Pos.x = -gridX * (numX - 1) / 2.0f;
         }
     }
 }

Yes, I am creating a plane with tiled objects. The primitive is a custom four-vertex plane. I did not use the default on purpose. The last two lines ensure that it is always starting at the top-left edge of the visible area. I've fixed the .euler, thanks. Nothing is scaling because the object itself is scaled, although scaling it via code may be more effective. They need to be scaled in order to fit an area they can be 'knocked out' in, IE - clicked on and they vanish.