Snap Terrain to Building/Structure

Hi,

I would like my terrain to snap to buildings placed on it. I got the basics, but I cannot get it to work correctly. Sometimes the results go into the right direction, however often they are far off.

In a nutshell I use the transform position as a reference height and then interpolate between the lower vectors of the bounding volume. The code for terraforming itself can be found on the forums already, but I will post it to show where I am standing currently.

         float distance = Vector3.Distance (start, end);
         float segmentSize = 0.2f;
         int tiles = Mathf.CeilToInt (distance / segmentSize);
         
         for (int t = 0; t < tiles; t++) {
             
             Vector3 tempPosition = Vector3.Lerp (start, end, t / (tiles-1));
         
             Terrain tempTerrain = GetTerrainTile(tempPosition);
             // get the normalized position of this game object relative to the terrain
             Vector3 tempCoord = (tempPosition - tempTerrain.gameObject.transform.position);
             Vector3 tempCoordNormalized = new Vector3(0,0,0);
             tempCoordNormalized.x = tempCoord.x / tempTerrain.terrainData.size.x;
             tempCoordNormalized.y = tempCoord.y / tempTerrain.terrainData.size.y;
             tempCoordNormalized.z = tempCoord.z / tempTerrain.terrainData.size.z;
              
             // get the position of the terrain heightmap where this game object is
             posXInTerrain = (int)(tempCoordNormalized.x * tempTerrain.terrainData.heightmapWidth);
             posYInTerrain = (int)(tempCoordNormalized.z * tempTerrain.terrainData.heightmapWidth);
             
             // we set an offset so that all the raising terrain is under this game object
             int size = 1;
             float desiredHeight = height/tempTerrain.terrainData.heightmapScale.y;
              
             // get the heights of the terrain under this game object
             float[,] heights = tempTerrain.terrainData.GetHeights (posXInTerrain, posYInTerrain, size, size);
             // we set each sample of the terrain in the size to the desired height
             for (int i=0; i<size; i++)
                 for (int j=0; j<size; j++)
                     heights [i, j] = desiredHeight;
             
             // set the new height
             tempTerrain.terrainData.SetHeights (posXInTerrain, posYInTerrain, heights);
         }

Any help or hint would be appreciated.