HOWTO: Generate a procedural texture

In this tutorial, you will learn how to create a simple texture from C# script code.

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

Tutorial

1. Create a new C# script named TextureFromCode

2. Write the texture data generating code

• C#
• C++

public class TextureFromCode : Script
{
    private Texture _tempTexture;
    private MaterialInstance _tempMaterialInstance;

    public Material Material;
    public Model Model;

    public override unsafe void OnStart()
    {
        // Ensure that model asset is loaded
        if (Model.WaitForLoaded())
            return;

        // Create new texture asset
        var texture = Content.CreateVirtualAsset<Texture>();
        _tempTexture = texture;
        var initData = new TextureBase.InitData();
        initData.Width = 64;
        initData.Height = 64;
        initData.ArraySize = 1;
        initData.Format = PixelFormat.R8G8B8A8_UNorm;
        var data = new byte[initData.Width * initData.Height * PixelFormatExtensions.SizeInBytes(initData.Format)];
        fixed (byte* dataPtr = data)
        {
            // Generate pixels data (linear gradient)
            var colorsPtr = (Color32*)dataPtr;
            for (int y = 0; y < initData.Height; y++)
            {
                float t1 = (float)y / initData.Height;
                var c1 = Color32.Lerp(Color.Red, Color.Blue, t1);
                var c2 = Color32.Lerp(Color.Yellow, Color.Green, t1);
                for (int x = 0; x < initData.Width; x++)
                {
                    float t2 = (float)x / initData.Width;
                    colorsPtr[y * initData.Width + x] = Color32.Lerp(c1, c2, t2);
                }
            }
        }
        initData.Mips = new[]
        {
            // Initialize mip maps data container description
            new TextureBase.InitData.MipData
            {
                Data = data,
                RowPitch = data.Length / initData.Height,
                SlicePitch = data.Length
            },
        };
        if (texture.Init(ref initData))
            return;

        // Use a dynamic material instance with a texture to sample
        var material = Material.CreateVirtualInstance();
        _tempMaterialInstance = material;
        material.SetParameterValue("tex", texture);

        // Add a model actor and use the dynamic material for rendering
        var staticModel = Actor.GetOrAddChild<StaticModel>();
        staticModel.Model = Model;
        staticModel.SetMaterial(0, material);
    }

    public override void OnDestroy()
    {
        // Ensure to cleanup resources
        FlaxEngine.Object.Destroy(ref _tempTexture);
        FlaxEngine.Object.Destroy(ref _tempMaterialInstance);
    }
}

3. Create the material

Create a simple material that contains a public texture parameter named tex. It's used by the script to assign a texture to draw.

4. Link the material and model

Add created script TextureFromCode to an actor in your scene (or create a new one for it). Then select the actor and assign the model and created material (as shown in a picture below).

5. Test it out!

Press Play (or F5) and see the results!