Create Bump by Code

News & General Discussion
1

Hi all
How to create bump form a texture by code?(Not use Editor and UnityEditor Clases).

2

The algorithm for this has been discussed in the forums a while ago. The source texture has to be marked as “Read/Write Enabled”. For huge textures this algorithm will take a fair amount of time.

public static Texture2D GenerateNormalMap(Texture2D source, float strength)
{
    Texture2D result;

    float xLeft, xRight;
    float yUp, yDown;
    float xDelta, yDelta;

    result = new Texture2D(source.width, source.height, TextureFormat.ARGB32, true);

    for (int by = 0; by < result.height; by++)
    for (int bx = 0; bx < result.width;  bx++)
    {
        xLeft  = source.GetPixel(bx - 1, by).grayscale * strength;
        xRight = source.GetPixel(bx + 1, by).grayscale * strength;
        yUp    = source.GetPixel(bx, by - 1).grayscale * strength;
        yDown  = source.GetPixel(bx, by + 1).grayscale * strength;
        xDelta = ((xLeft - xRight) + 1) * 0.5f;
        yDelta = ((yUp - yDown) + 1) * 0.5f;
        result.SetPixel(bx, by, new Color(xDelta, yDelta, 1, yDelta));
    }

    result.Apply();

    return result;
}

Using the “Pixel32” methods instead of “Pixel” will be quite a bit faster as it uses the byte based Color32 structure that uses only 48 bit compared to the 432 bit of the Color structure.

3

Thanks a lot.