private void GenerateNormalsMap(Texture2D horizontals, Texture2D verticals)
{
// Create the asset if not existing yet
if (OutputTexture == null)
{
OutputTexture = new Texture2D(Mathf.Max(horizontals.width, verticals.width), Mathf.Max(horizontals.height, verticals.height), TextureFormat.RGBA32, false);
}
// Actual map generation
Color[] outputPixels = new Color[OutputTexture.width * OutputTexture.height];
float uNormalized = 0.0f, vNormalized = 0.0f;
Color ch, cv;
float r, g, b;
Vector2 xyNormal;
Vector3 normal;
for (int v = 0; v < OutputTexture.height; ++v)
{
vNormalized = (float)v / OutputTexture.height;
for (int u = 0; u < OutputTexture.width; ++u)
{
uNormalized = (float)u / OutputTexture.width;
ch = horizontals.GetPixelBilinear(uNormalized, vNormalized);
r = ch.r * 2.0f - 1.0f;
cv = verticals.GetPixelBilinear(uNormalized, vNormalized);
g = cv.g * 2.0f - 1.0f;
xyNormal = Vector2.ClampMagnitude(new Vector2(r, g), 0.999f);
r = xyNormal.x;
g = xyNormal.y;
b = (float)Math.Sqrt(1.0f - (double)(r * r) - (double)(g * g)); // z = sqrt (1 - x^2 - y^2)
normal = new Vector3(r, g, b).normalized;
outputPixels[u + v * OutputTexture.width] = new Color(normal.x * 0.5f + 0.5f, normal.y * 0.5f + 0.5f, normal.z * 0.5f + 0.5f, 1.0f);
}
}
OutputTexture.SetPixels(outputPixels);
OutputTexture.Apply();
File.WriteAllBytes(Path.GetDirectoryName(Application.dataPath) + "/Assets/SpriteNormals.png", OutputTexture.EncodeToPNG());
AssetDatabase.ImportAsset("Assets/SpriteNormals.png");
OutputTexture = AssetDatabase.LoadMainAssetAtPath("Assets/SpriteNormals.png") as Texture2D;
}
}
