Procedural Terrain Height map can't be applied to Terrain data

Unity Engine
1

I’ve been trying to create procedural terrain for a game. I keep getting the error: “ArgumentException: X or Y base out of bounds. Setting up to 4096x4096 while map size is 33x33” when setting my generated height map to the terraindata. Anyone know a fix for this?

    void GenerateTerrainData()
    {
        terrain.terrainData.heightmapResolution = resolution;
        terrain.terrainData.baseMapResolution = resolution;

        terrain.terrainData.size = new Vector3(length, height, width);
        terrain.terrainData.SetHeights(0, 0, GenerateHeights());
    }

    float[,] GenerateHeights()
    {
        float[,] heights = new float[length * resolution, width * resolution];
        Debug.Log("heights[" + heights.GetLength(0) + "," + heights.GetLength(1) + "]");

        for (int x = 0; x < length; x++)
        {
            for (int y = 0; y < width; y++)
            {
                switch (heightType)
                {
                    default:
                    case HeightType.perlin:
                        heights[x, y] = GeneratePerlinHeight(x);
                        break;

                    case HeightType.multiFreqPerlin:
                        heights[x, y] = GenerateMultiFreqPerlinHeight(x, y);
                        break;

                    case HeightType.multiFreqNoise:
                        heights[x, y] = GenerateMulitFreqNoiseHeight(x);
                        break;
                }
             
            }
        }

        return heights;
    }
2

You’re trying to apply a bigger heightmap than the current heightmap resolution of the terrain. The fault is in the 12th line.

float[,] heights = new float[length * resolution, width * resolution];

Lets say length = 10 and width = 10 and the terrain resolution is 33x33. In that case you’d be applying a 330x330 resolution heightmap onto a 33x33 terrain’s heightmap via SetHeights(0, 0, GenerateHeights()), hence the error being out of bounds.

Also Unity only supports 2^n + 1 heightmap resolutions going from 33x33 to 4097x4097. In the line 3rd line:

terrain.terrainData.heightmapResolution = resolution;

make sure that the resolution follows the previous formula

3

So if I understand you, the heightmap resolution has to be the same as the length and the width? Is there any way to make terrain in the shape of a rectangle, not a square?

4

You can make the terrain into a rectangle via changing the terrain size, however, the resolution of the heightmap will always be the same for Z and X axis. If you’re looking to stretch the heightmap data and not just the size of the terrain, you could probably do so by changing your GenerateMultiFreqPerlinHeight(x, y) inputs into something like GenerateMultiFreqPerlinHeight(x * multiplier, y) which should stretch the X axis heightmap data more if multiplier > 1 and shrink if multiplier < 1.

5

I was only looking to change the terrain base shape, so editing the terrain data size worked. Thanks for the help!