NormalSampling.java

private static Texture generateNormalMapTexture(int width, int height, Pixmap pm) {
        pixmap = new Pixmap(width, height, Pixmap.Format.RGBA8888);
        texture = new Texture(width, height, Pixmap.Format.RGBA8888);

        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                Vector3 currentVertex = new Vector3(x, getPixelWrap(x, y, width, height, pm), y);
                Vector3 pU = new Vector3(x + 1, getPixelWrap(x + 1, y, width, height, pm), y);
                Vector3 pV = new Vector3(x, getPixelWrap(x, y + 1, width, height, pm), y + 1);

                Vector3 dpU = negate(currentVertex.cpy().sub(pU));
                Vector3 dpV = currentVertex.cpy().sub(pV);

                Vector3 normal = dpU.cpy().crs(dpV).nor();

                Vector3 normalRGB = normal.cpy().scl(0.5f).add(0.5f);
                
                pixmap.drawPixel(x, y, new Color(normalRGB.x, normalRGB.z, normalRGB.y, 1).toIntBits());
            }
        }


        PixmapIO.writePNG(Gdx.files.getFileHandle("normalmap.png", Files.FileType.Local), pixmap);
        texture.setWrap(Texture.TextureWrap.ClampToEdge, Texture.TextureWrap.ClampToEdge);
        texture.draw(pixmap, 0, 0);
        return texture;
    }