A wizard to render a scene and create a cubemap image

CubeMapRenderer.cs

using UnityEngine;
using UnityEditor;
using System.IO;

public class CubeMapRenderer : ScriptableWizard {
    [SerializeField]
    Shader TransformShader;
    [SerializeField]
    Camera RenderCamera;
    [SerializeField]
    string Path = "Assets/NewCubemap.png";

    const int resolution = 2048;
    void OnWizardCreate()
    {
        if(RenderCamera==null)
            RenderCamera = Camera.main;
        Cubemap newcubemap = new Cubemap(resolution, TextureFormat.ARGB32, false);
        RenderCamera.RenderToCubemap(newcubemap);

        Material mat = new Material(TransformShader);
        RenderTexture newtexture = new RenderTexture(resolution * 2, resolution, 16, RenderTextureFormat.ARGB32);
        Graphics.Blit(newcubemap, newtexture, mat);
        DestroyImmediate(mat);

        SaveImage(newtexture, Path);
        DestroyImmediate(newcubemap);
        DestroyImmediate(newtexture);
    }

    void SaveImage(RenderTexture texture, string path){
        Texture2D savetexture = new Texture2D(texture.width, texture.height, TextureFormat.RGB24, false);

        var activeamp = RenderTexture.active;
        RenderTexture.active = texture;
        savetexture.ReadPixels(new Rect(0, 0, texture.width, texture.height), 0, 0);
        savetexture.Apply();
        RenderTexture.active = activeamp;

        byte[] data = savetexture.EncodeToPNG();
        File.WriteAllBytes(path, data);
        DestroyImmediate(savetexture);
    }

    [MenuItem("Window/Render2Cubemap")]
    static void ShowREnderWizard()
    {
        DisplayWizard<CubeMapRenderer>("cubemap renderer", "Render");
    }
}

TransformCube2D.shader

Shader "Custom/TransformCube2D"
{
    Properties
    {
        _MainTex("Texture", CUBE) = "white" {}
    }
        SubShader
    {
        Tags { "RenderType" = "Opaque" }
        LOD 100

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };

            samplerCUBE _MainTex;

            v2f vert(appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                return o;
            }

            fixed4 frag(v2f i) : SV_Target
            {
                i.uv.x *= UNITY_PI * 2;
                i.uv.y *= UNITY_PI;
                float3 vec;
                vec.x = sin(i.uv.y)*sin(i.uv.x);
                vec.y = -cos(i.uv.y);
                vec.z = sin(i.uv.y)*cos(i.uv.x);
                fixed4 col = texCUBE(_MainTex, vec);
                return col;
            }
            ENDCG
        }
    }
}