HOWTO: Generate procedural models

Model

In this tutorial you will learn how to create a simple icosahedron mesh.

This sample uses the C# API method Content.CreateVirtualAsset to generate a procedural model resource which can be modified at runtime from code.

Mesh Accessor

When editing larger models or when perfoming real-time mesh editing use MeshAccessor that provides robust per-component access for vertex elements. It supports various data formats (including packed R10G10B10A2 and others) with automatic convertion between vector or scalar values.

Tutorial

1. Create new C# script ModelGenerator

2. Write a mesh data generating function

private void UpdateMesh(Mesh mesh)
{
    const float X = 0.525731112119133606f;
    const float Z = 0.850650808352039932f;
    const float N = 0.0f;
    var vertices = new[]
    {
        new Float3(-X, N, Z),
        new Float3(X, N, Z),
        new Float3(-X, N, -Z),
        new Float3(X, N, -Z),
        new Float3(N, Z, X),
        new Float3(N, Z, -X),
        new Float3(N, -Z, X),
        new Float3(N, -Z, -X),
        new Float3(Z, X, N),
        new Float3(-Z, X, N),
        new Float3(Z, -X, N),
        new Float3(-Z, -X, N)
    };
    var triangles = new[]
    {
        1, 4, 0, 4, 9, 0, 4, 5, 9, 8, 5, 4,
        1, 8, 4, 1, 10, 8, 10, 3, 8, 8, 3, 5,
        3, 2, 5, 3, 7, 2, 3, 10, 7, 10, 6, 7,
        6, 11, 7, 6, 0, 11, 6, 1, 0, 10, 1, 6,
        11, 0, 9, 2, 11, 9, 5, 2, 9, 11, 2, 7
    };
    mesh.UpdateMesh(vertices, triangles, vertices);
}

3. Create a model asset and model actor in the OnStart function

private Model _model;

public MaterialBase Material;

public override void OnStart()
{
    // Create dynamic model with a single LOD with one mesh
    _model = Content.CreateVirtualAsset<Model>();
    _model.SetupLODs(new[] { 1 });
    UpdateMesh(_model.LODs[0].Meshes[0]);

    // Create or reuse child model
    var childModel = Actor.GetOrAddChild<StaticModel>();
    childModel.Model = _model;
    childModel.LocalScale = new Float3(100);
    childModel.SetMaterial(0, Material);
}

public override void OnDestroy()
{
    FlaxEngine.Object.Destroy(ref _model);
}

Remember to dispose of all of the resources created at runtime to prevent memory leaks.

4. Add the script and set the material

Model

5. See the result

Model