ScreenshotSequence.cs

using UnityEngine;
using UnityEditor;
public class Screenshots : EditorWindow {
    bool groupEnabled;
    int lastCapturedFrame = -1;

    bool recording;

    public string folder = "Screenshots/Sequence";
    public int frameRate = 25;
    public int sizeMultiplier = 1;


    private string realFolder = "";


    // Add menu named "My Window" to the Window menu
    [MenuItem ("Window/Screenshot")]
    static void Init () {
        // Get existing open window or if none, make a new one:
        Screenshots window = (Screenshots)EditorWindow.GetWindow (typeof (Screenshots));
        window.Show();
    }

    void OnGUI () {

        if (GUILayout.Button("Single Screenshot"))
        {
            SingleScreenshot();
        }

        if(!EditorApplication.isPlaying && recording)
        {
            StopRecording();
        }

        if (recording)
        {
            if (GUILayout.Button("Stop Recording"))
            {
                StopRecording();
            }
        }
        else
        {
            if (GUILayout.Button("Start Recording"))
            {
                StartRecording();
            }
        }


        groupEnabled = EditorGUILayout.BeginToggleGroup ("Optional Settings", groupEnabled);
        folder = EditorGUILayout.TextField ("Folder name", folder);
        frameRate = EditorGUILayout.IntField ("Capture frame rate", frameRate);
        sizeMultiplier = EditorGUILayout.IntField ("Size Multiplier", sizeMultiplier);
        EditorGUILayout.EndToggleGroup ();

        if (realFolder != "")
        {
            if (GUILayout.Button("Open Last Folder"))
            {
                OpenInFileBrowser.Open(realFolder);
            }
        }

    }


    static void SingleScreenshot()
    {
        Application.CaptureScreenshot("Screenshots/" + System.DateTime.Now.ToString("s") + ".png", 2);

    }


    void StopRecording()
    {
        recording = false;
    }


    void StartRecording()
    {
        // Set the playback framerate!
        // (real time doesn't influence time anymore)
        Time.captureFramerate = frameRate;

        // Find a folder that doesn't exist yet by appending numbers!
        realFolder = folder;
        int count = 1;
        while (System.IO.Directory.Exists(realFolder))
        {
            realFolder = folder + count;
            count++;
        }
        // Create the folder
        System.IO.Directory.CreateDirectory(realFolder);

        recording = true;

        lastCapturedFrame = Time.frameCount;
    }

    void Update()
    {

        if (recording && Time.frameCount > lastCapturedFrame && EditorApplication.isPlaying && !EditorApplication.isPaused)
        {
            lastCapturedFrame = Time.frameCount;

            // name is "realFolder/shot 000005.png"
            var name = string.Format("{0}/shot {1:D06}.png", realFolder, Time.frameCount);

            // Capture the screenshot
            Application.CaptureScreenshot(name, sizeMultiplier);
        }
    }
}


public static class OpenInFileBrowser
{
    public static bool IsInMacOS
    {
        get
        {
            return UnityEngine.SystemInfo.operatingSystem.IndexOf("Mac OS") != -1;
        }
    }

    public static bool IsInWinOS
    {
        get
        {
            return UnityEngine.SystemInfo.operatingSystem.IndexOf("Windows") != -1;
        }
    }

    public static void Test()
    {
        Open(UnityEngine.Application.dataPath);
    }

    public static void OpenInMac(string path)
    {
        bool openInsidesOfFolder = false;

        // try mac
        string macPath = path.Replace("\\", "/"); // mac finder doesn't like backward slashes

        if ( System.IO.Directory.Exists(macPath) ) // if path requested is a folder, automatically open insides of that folder
        {
            openInsidesOfFolder = true;
        }

        if ( !macPath.StartsWith("\"") )
        {
            macPath = "\"" + macPath;
        }

        if ( !macPath.EndsWith("\"") )
        {
            macPath = macPath + "\"";
        }

        string arguments = (openInsidesOfFolder ? "" : "-R ") + macPath;

        try
        {
            System.Diagnostics.Process.Start("open", arguments);
        }
        catch ( System.ComponentModel.Win32Exception e )
        {
            // tried to open mac finder in windows
            // just silently skip error
            // we currently have no platform define for the current OS we are in, so we resort to this
            e.HelpLink = ""; // do anything with this variable to silence warning about not using it
        }
    }

    public static void OpenInWin(string path)
    {
        bool openInsidesOfFolder = false;

        // try windows
        string winPath = path.Replace("/", "\\"); // windows explorer doesn't like forward slashes

        if ( System.IO.Directory.Exists(winPath) ) // if path requested is a folder, automatically open insides of that folder
        {
            openInsidesOfFolder = true;
        }

        try
        {
            System.Diagnostics.Process.Start("explorer.exe", (openInsidesOfFolder ? "/root," : "/select,") + winPath);
        }
        catch ( System.ComponentModel.Win32Exception e )
        {
            // tried to open win explorer in mac
            // just silently skip error
            // we currently have no platform define for the current OS we are in, so we resort to this
            e.HelpLink = ""; // do anything with this variable to silence warning about not using it
        }
    }

    public static void Open(string path)
    {
        if ( IsInWinOS )
        {
            OpenInWin(path);
        }
        else if ( IsInMacOS )
        {
            OpenInMac(path);
        }
        else // couldn't determine OS
        {
            OpenInWin(path);
            OpenInMac(path);
        }
    }
}