[SOLVED] C# | Unity | Check if Terrain is flat enough

Hey Guys,
i wrote a method to check if a terrain is flat enough to place a building on it. The building should have an empty child called testPoints. The testPoints object also has 5 empty objects(one for each corner and one in the middle). Now I loop through all children of testPoints and raycast down. In the end I compare the highest RaycastHit and the lowest RaycastHit to see if the difference is acceptable.

Error:
The function always returns True. With the debugger I found out that the names of the Points change but the position always stays the same and the RaycastHit object is null the whole time. I also just see one Raycast, but they should be spread.

Check() method:

Code (CSharp):

1. using UnityEngine;
2.     public bool Check ()
3.     {
4.         float max = 0F;
5.         float min = 0F;
6.         RaycastHit hitInfo;
7.         foreach (Transform point in testPoints.transform) {
8.             Physics.Raycast (point.position, Vector3.down, out hitInfo, Mathf.Infinity, LayerMask.NameToLayer ("SolidGround"));
9.             Debug.DrawRay (point.position, new Vector3 (0, -10, 0), Color.red);
10.             if (hitInfo.point.y > max) {
11.                 max = hitInfo.point.y;
12.             } else if (hitInfo.point.y < min) {
13.                 min = hitInfo.point.y;
14.             }
15.         }
16.         return (max - min) < maxDifference;
17.     }
18.  

Sorry for bad English and
Thanks in advance!

 

nothing wrong on that front, nice first post

usually with 3d raycasts they're couched in an if so

Code (csharp):

1.  
2. if(Physics.Raycast(point.position, Vector3.down, out hitInfo, Mathf.Infinity, LayerMask.NameToLayer("SolidGround")))
3. {
4. // hitInfo isn't going to be null in here
5. }
6.  

first thought would be to check the layer on the terrain is set correctly...

this sounds very odd, I can't see anything wrong with the syntax, so assuming there are children it should iterate over them, what debug code did you use?

 

Thanks for the quick reply!

I fixed the problem with the same position(turns out I just spawned them and didn't move them to the corners ).
The terrain is on the right layer, I also added an if statement but it seems like the raycast isn't hitting anything.
Here's the new code:

Code (CSharp):

1. public bool Check ()
2.     {
3.         float max = 0F;
4.         float min = 0F;
5.         RaycastHit hitInfo;
6.         foreach (Transform point in testPoints.transform) {
7.             Debug.DrawRay (point.position, new Vector3 (0, -10, 0), Color.red);
8.             if (Physics.Raycast (point.position, Vector3.down, out hitInfo, Mathf.Infinity, LayerMask.NameToLayer ("SolidGround"))) {
9.                 if (hitInfo.point.y > max) {
10.                     max = hitInfo.point.y;
11.                 } else if (hitInfo.point.y < min) {
12.                     min = hitInfo.point.y;
13.                 }
14.             }
15.         }
16.         return (max - min) < maxDifference;
17.     }

 

Ok, got it working now, I changed 'LayerMask.NameToLayer' to 'LayerMask.GetMask' at line 8.