Time.captureDeltaTime

Description

Slows game playback time to allow screenshots to be saved between frames.

If this property has a non-zero value then frame update will occur at an interval of captureDeltaTime regardless of real time and the time required to render a frame. This is useful if you want to capture a movie where you need a constant frame rate and leave enough time between frames to save screen images.

using UnityEngine;
using System.Collections;

// Capture frames as a screenshot sequence. Images are
// stored as PNG files in a folder - these can be combined into
// a movie using image utility software (eg, QuickTime Pro).

public class ExampleClass : MonoBehaviour
{
    // The folder to contain our screenshots.
    // If the folder exists we will append numbers to create an empty folder.
    public string folder = "ScreenshotFolder";
    public int frameRate = 25;
    void Start()
    {
        // Set the playback framerate (real time will not relate to game time after this).
        Time.captureDeltaTime = 1.0f / frameRate;

        // Create the folder
        System.IO.Directory.CreateDirectory(folder);
    }

    void Update()
    {
        // Append filename to folder name (format is '0005 shot.png"')
        string name = string.Format("{0}/{1:D04} shot.png", folder, Time.frameCount);

        // Capture the screenshot to the specified file.
        ScreenCapture.CaptureScreenshot(name);
    }
}