Convert matcap to cubemap (Unity 5.0)

gistfile1.cs

using UnityEngine;
using UnityEditor;

public class MatcapToCubemap : ScriptableWizard {
	public Texture matcap;
	public float emissionScale = 1f;
	public int size = 256;

	void OnWizardUpdate () {
		this.isValid = this.matcap != null;
	}

	void OnWizardCreate () {
		var sphere = GameObject.CreatePrimitive (PrimitiveType.Sphere);
		sphere.transform.position = new Vector3 (
			Random.Range (1000, 2000),
			Random.Range (1000, 2000),
			Random.Range (1000, 2000));

		var meshFilter = sphere.GetComponent<MeshFilter> ();
		var mesh = Object.Instantiate (meshFilter.sharedMesh);
		var normals = mesh.normals;
		var uv = mesh.uv;
		for (int i = 0; i < normals.Length; ++i) {
			var n = normals[i];
			normals[i] = -n;
			uv[i] = new Vector2 (n.x + 1f, n.y + 1f) * 0.5f;
		}
		mesh.normals = normals;
		mesh.uv = uv;
		var triangles = mesh.triangles;
		for (int i = 0; i < triangles.Length; i+=3) {
			var a = triangles[i];
			var b = triangles[i + 1];
			triangles[i] = b;
			triangles[i + 1] = a;
		}
		mesh.triangles = triangles;
		meshFilter.mesh = mesh;

		var shader = Shader.Find ("Standard");
		var mat = new Material (shader);
		mat.color = Color.black;
		mat.SetTexture ("_EmissionMap", matcap);
		mat.SetColor ("_EmissionColor", Color.white);
		mat.SetFloat ("_EmissionScaleUI", this.emissionScale);
		mat.shaderKeywords = new string[] {"_EMISSION"};
		var meshRenderer = sphere.GetComponent<MeshRenderer> ();
		meshRenderer.material = mat;

		var cubemap = new Cubemap (this.size, TextureFormat.ARGB32, false);
		var camera = sphere.AddComponent<Camera> ();
		camera.nearClipPlane = 0.01f;
		camera.farClipPlane = 10f;
		camera.RenderToCubemap (cubemap);
		DestroyImmediate (sphere);

		var tex2d = new Texture2D (this.size, this.size * 6, TextureFormat.ARGB32, false);
		var faceList = new CubemapFace[] {
			CubemapFace.NegativeZ,
			CubemapFace.PositiveZ,
			CubemapFace.NegativeY,
			CubemapFace.PositiveY,
			CubemapFace.NegativeX,
			CubemapFace.PositiveX,
		};
		for (int i = 0; i < 6; ++i) {
			var pixels = cubemap.GetPixels (faceList[i]);
			System.Array.Reverse (pixels);
			for (int j = 0; j < this.size; ++j) {
				System.Array.Reverse (pixels, j * this.size, this.size);
			}
			tex2d.SetPixels (0, i * this.size, this.size, this.size, pixels);
		}
		tex2d.Apply ();

		var data = tex2d.EncodeToPNG ();
		if (data != null) {
			var path = EditorUtility.SaveFilePanelInProject (
				"Save", "cubemap.png", "png", "Save the cubemap texture.");
			System.IO.File.WriteAllBytes (path, data);
			MatcapToCubemapAssetPostprocessor.cubmapPath = path;
			AssetDatabase.ImportAsset (path);
		}
	}

	[MenuItem ("Assets/Render cubemap from matcap")]
	static void RenderCubemap () {
		var wizard = ScriptableWizard.DisplayWizard <MatcapToCubemap> ("Render cubemap from matcap", "Render!");
		var texture = Selection.activeObject as Texture;
		if (texture != null) {
			wizard.matcap = texture;
			wizard.isValid = true;
		}
	}
}

public class MatcapToCubemapAssetPostprocessor : AssetPostprocessor {
	static public string cubmapPath;
	void OnPreprocessTexture () {
		if (this.assetPath == cubmapPath) {
			var textureImporter = this.assetImporter as TextureImporter;
			textureImporter.textureType = TextureImporterType.Cubemap;
			textureImporter.anisoLevel = 0;
			textureImporter.generateCubemap = TextureImporterGenerateCubemap.AutoCubemap;
			cubmapPath = null;
		}
	}
}