Mesh deformation using 3d Perlin noise

Unity Engine
1

I wanted to play around with Perlin noise for a bit and tried to deform some with 3d Perlin noise but I doesn’t deform when run. I dont know surely I am overseeing something here but I dont know what.

Mesh GenerateMesh(float scale, float frequency)
    {
        Mesh _mesh = new Mesh();
        Vector3[] baseVertices;

        Mesh mesh = GetComponent<MeshFilter>().mesh;
        baseVertices = _mesh.vertices;
        Vector3[] vertices = new Vector3[baseVertices.Length];

        for (int i = 0; i < vertices.Length; i++)
        {
            Vector3 vertex = baseVertices[i];

            // Normalise the cube to make a quadsphere
            vertex = vertex.normalized;

            float fractalNoise = PerlinNoise.Perlin3D(vertex, frequency);

            vertex.x += fractalNoise * scale;
            vertex.y += fractalNoise * scale;
            vertex.z += fractalNoise * scale;

            vertices[i] = vertex;
        }

        _mesh.vertices = vertices;

        _mesh.RecalculateNormals();
        _mesh.RecalculateBounds();

        return _mesh;
    }

The Perlin noise code works I tested that so it has to so something with the actual deformation of the mesh.

2

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also put in Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

https://discussions.unity.com/t/839300/3

3

@Kurt-Dekker lets just say my big brain forgot to assign the mesh to the meshFilter :slight_smile: sorry to waste your time like that

1 Like