Take snapshot images of Prefabs and GameObjects in Unity using Render Textures

example-snapshot.png

SnapshotCamera.cs

using UnityEditor;
using UnityEngine;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;

// Object rendering code based on Dave Carlile's "Create a GameObject Image Using Render Textures" post
// Link: http://crappycoding.com/2014/12/create-gameobject-image-using-render-textures/

/// <summary>
/// Takes snapshot images of prefabs and GameObject instances, and provides methods to save them as PNG files.
/// </summary>
public class SnapshotCamera : MonoBehaviour {
    // This disables the "never assigned" warning.
    // These fields will be assigned by the factory.
    #pragma warning disable 0649
    /// <summary>
    /// The Camera used internally by the SnapshotCamera.
    /// </summary>
    private Camera cam;
    /// <summary>
    /// The layer on which the SnapshotCamera takes snapshots.
    /// </summary>
    private int layer;
    #pragma warning restore 0649

    /// <summary>
    /// The default position offset applied to objects when none is specified.
    /// </summary>
    public Vector3 defaultPositionOffset = new Vector3(0, 0, 1);
    /// <summary>
    /// The default rotation applied to objects when none is specified.
    /// </summary>
    public Vector3 defaultRotation = new Vector3(345.8529f, 313.8297f, 14.28433f);
    /// <summary>
    /// The default scale applied to objects when none is specified.
    /// </summary>
    public Vector3 defaultScale = new Vector3(1, 1, 1);

    // This private constructor serves to ensure only the factory can produce new instances.
    private SnapshotCamera () { }

    /// <summary>
    /// Factory method which sets up and configures a new SnapshotCamera, then returns it.
    /// </summary>
    /// <param name="layer">The name of the layer on which to take snapshots.</param>
    /// <param name="name">The name that will be given to the new GameObject the SnapshotCamera will be attached to.</param>
    /// <returns>A new SnapshotCamera, ready for use.</returns>
    public static SnapshotCamera MakeSnapshotCamera (string layer, string name = "Snapshot Camera")
    {
        return MakeSnapshotCamera(LayerMask.NameToLayer(layer), name);
    }

    /// <summary>
    /// Factory method which sets up and configures a new SnapshotCamera, then returns it.
    /// </summary>
    /// <param name="layer">The layer number of the layer on which to take snapshots.</param>
    /// <param name="name">The name that will be given to the new GameObject the SnapshotCamera will be attached to.</param>
    /// <returns>A new SnapshotCamera, ready for use.</returns>
    public static SnapshotCamera MakeSnapshotCamera (int layer = 5, string name = "Snapshot Camera")
    {
        if (layer < 0 || layer > 31)
            throw new ArgumentOutOfRangeException("layer", "layer argument must specify a valid layer between 0 and 31");

        // Create a new GameObject to hold the camera
        GameObject snapshotCameraGO = new GameObject(name);
        // Add a Camera component to the GameObject
        Camera cam = snapshotCameraGO.AddComponent<Camera>();

        // Configure the Camera
        cam.cullingMask = 1 << layer;
        cam.orthographic = true;
        cam.orthographicSize = 1;
        cam.clearFlags = CameraClearFlags.SolidColor;
        cam.backgroundColor = Color.clear;
        cam.nearClipPlane = 0.1f;
        cam.enabled = false;
        
        // Add a SnapshotCamera component to the GameObject
        SnapshotCamera snapshotCamera = snapshotCameraGO.AddComponent<SnapshotCamera>();
        
        // Set the SnapshotCamera's cam and layer fields
        snapshotCamera.cam = cam;
        snapshotCamera.layer = layer;

        // Return the SnapshotCamera
        return snapshotCamera;
    }

    #region PNG saving
    /// <summary>
    /// Sanitizes a filename string by replacing illegal characters with underscores.
    /// </summary>
    /// <param name="dirty">The unsanitized filename string.</param>
    /// <returns>A sanitized filename string with illegal characters replaced with underscores.</returns>
    private static string SanitizeFilename (string dirty)
    {
        string invalidFileNameChars = Regex.Escape(new string(Path.GetInvalidFileNameChars()));
        string invalidRegStr = string.Format(@"([{0}]*\.+$)|([{0}]+)", invalidFileNameChars);

        return Regex.Replace(dirty, invalidRegStr, "_");
    }

    /// <summary>
    /// Saves a byte array of PNG data as a PNG file.
    /// </summary>
    /// <param name="bytes">The PNG data to write to a file.</param>
    /// <param name="filename">The name of the file. This will be the current timestamp if not specified.</param>
    /// <param name="directory">The directory in which to save the file. This will be the game/Snapshots directory if not specified.</param>
    /// <returns>A FileInfo pointing to the created PNG file</returns>
    public static FileInfo SavePNG (byte[] bytes, string filename = "", string directory = "")
    {
        directory = directory != "" ? Directory.CreateDirectory(directory).FullName : Directory.CreateDirectory(Path.Combine(Application.dataPath, "../Snapshots")).FullName;
        filename = filename != "" ? SanitizeFilename(filename) + ".png" : System.DateTime.Now.ToString("yyyy-MM-dd-HH-mm-ss-ffff") + ".png";
        string filepath = Path.Combine(directory, filename);

        File.WriteAllBytes(filepath, bytes);

        return new FileInfo(filepath);
    }

    /// <summary>
    /// Saves a Texture2D as a PNG file.
    /// </summary>
    /// <param name="tex">The Texture2D to write to a file.</param>
    /// <param name="filename">The name of the file. This will be the current timestamp if not specified.</param>
    /// <param name="directory">The directory in which to save the file. This will be the game/Snapshots directory if not specified.</param>
    /// <returns>A FileInfo pointing to the created PNG file</returns>
    public static FileInfo SavePNG (Texture2D tex, string filename = "", string directory = "")
    {
        return SavePNG(tex.EncodeToPNG(), filename, directory);
    }
    #endregion

    #region Object preparation
    /// <summary>
    /// This stores the a state (layers, position, rotation, and scale) of a GameObject, and provides a method to restore it.
    /// </summary>
    private struct GameObjectStateSnapshot
    {
        private GameObject gameObject;
        private Vector3 position;
        private Quaternion rotation;
        private Vector3 scale;
        private Dictionary<GameObject, int> layers;

        /// <summary>
        /// Store the current state (layers, position, rotation, and scale) of a GameObject
        /// </summary>
        /// <param name="gameObject">The GameObject whose state to store.</param>
        public GameObjectStateSnapshot (GameObject gameObject)
        {
            this.gameObject = gameObject;
            this.position = gameObject.transform.position;
            this.rotation = gameObject.transform.rotation;
            this.scale = gameObject.transform.localScale;

            this.layers = new Dictionary<GameObject, int>();
            foreach (Transform t in gameObject.GetComponentsInChildren<Transform>(true))
            {
                this.layers.Add(t.gameObject, t.gameObject.layer);
            }
        }

        /// <summary>
        /// Restore the gameObject to the state stored in this GameObjectStateSnapshot.
        /// </summary>
        public void Restore ()
        {
            this.gameObject.transform.position = this.position;
            this.gameObject.transform.rotation = this.rotation;
            this.gameObject.transform.localScale = this.scale;

            foreach (KeyValuePair<GameObject, int> entry in this.layers)
            {
                entry.Key.layer = entry.Value;
            }
        }
    }

    /// <summary>
    /// Set the layers of the GameObject and all its children to the SnapshotCamera's snapshot layer so the SnapshotCamera can see it.
    /// </summary>
    /// <param name="gameObject">The GameObject apply the layer modifications to.</param>
    private void SetLayersRecursively (GameObject gameObject)
    {
        foreach (Transform transform in gameObject.GetComponentsInChildren<Transform>(true))
            transform.gameObject.layer = layer;
    }

    /// <summary>
    /// Prepares an instantiated GameObject for taking a snapshot by setting its layers and applying the specified position offset, rotation, and scale to it.
    /// </summary>
    /// <param name="prefab">The instantiated GameObject to prepare.</param>
    /// <param name="positionOffset">The position offset relative to the SnapshotCamera to apply to the gameObject.</param>
    /// <param name="rotation">The rotation to apply to the gameObject.</param>
    /// <param name="scale">The scale to apply to the gameObject.</param>
    /// <returns>A GameObjectStateSnapshot containing the state of the gameObject prior to modifying its layers, position, rotation, and scale.</returns>
    private GameObjectStateSnapshot PrepareObject (GameObject gameObject, Vector3 positionOffset, Quaternion rotation, Vector3 scale)
    {
        GameObjectStateSnapshot goss = new GameObjectStateSnapshot(gameObject);

        gameObject.transform.position = transform.position + positionOffset;
        gameObject.transform.rotation = rotation;
        gameObject.transform.localScale = scale;
        SetLayersRecursively(gameObject);

        return goss;
    }

    /// <summary>
    /// Prepares a prefab for taking a snapshot by creating an instance, setting its layers and applying the specified position offset, rotation, and scale to it.
    /// </summary>
    /// <param name="prefab">The prefab to prepare.</param>
    /// <param name="positionOffset">The position offset relative to the SnapshotCamera to apply to the prefab.</param>
    /// <param name="rotation">The rotation to apply to the prefab.</param>
    /// <param name="scale">The scale to apply to the prefab.</param>
    /// <returns>A prefab instance ready for taking a snapshot.</returns>
    private GameObject PreparePrefab (GameObject prefab, Vector3 positionOffset, Quaternion rotation, Vector3 scale)
    {
        GameObject gameObject = GameObject.Instantiate(prefab, transform.position + positionOffset, rotation) as GameObject;
        gameObject.transform.localScale = scale;
        SetLayersRecursively(gameObject);

        return gameObject;
    }
    #endregion

    #region TakeObjectSnapshot
    /// <summary>
    /// Takes a snapshot of an instantiated GameObject and returns it as a Texture2D.
    /// 
    /// Uses a completely transparent background and
    /// applies the default position offset, rotation and scale to the gameObject while taking the snapshot, and restores them afterwards.
    /// </summary>
    /// <param name="gameObject">The instantiated GameObject to snapshot.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    public Texture2D TakeObjectSnapshot (GameObject gameObject, int width = 128, int height = 128)
    {
        return TakeObjectSnapshot(gameObject, Color.clear, defaultPositionOffset, Quaternion.Euler(defaultRotation), defaultScale, width, height);
    }

    /// <summary>
    /// Takes a snapshot of an instantiated GameObject and returns it as a Texture2D.
    /// 
    /// Applies the default position offset, rotation and scale to the gameObject while taking the snapshot, and restores them afterwards.
    /// </summary>
    /// <param name="gameObject">The instantiated GameObject to snapshot.</param>
    /// <param name="backgroundColor">The background color of the snapshot. Can be transparent.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    public Texture2D TakeObjectSnapshot (GameObject gameObject, Color backgroundColor, int width = 128, int height = 128)
    {
        return TakeObjectSnapshot (gameObject, backgroundColor, defaultPositionOffset, Quaternion.Euler(defaultRotation), defaultScale, width, height);
    }

    /// <summary>
    /// Takes a snapshot of an instantiated GameObject and returns it as a Texture2D.
    /// 
    /// Uses a completely transparent background.
    /// </summary>
    /// <param name="gameObject">The instantiated GameObject to snapshot.</param>
    /// <param name="positionOffset">The position offset relative to the SnapshotCamera that will be applied to the gameObject while taking the snapshot. Its position will be restored after taking the snapshot.</param>
    /// <param name="rotation">The rotation that will be applied to the gameObject while taking the snapshot. Its rotation will be restored after taking the snapshot.</param>
    /// <param name="scale">The scale that will be applied to the gameObject while taking the snapshot. Its scale will be restored after taking the snapshot.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    public Texture2D TakeObjectSnapshot (GameObject gameObject, Vector3 positionOffset, Quaternion rotation, Vector3 scale, int width = 128, int height = 128)
    {
        return TakeObjectSnapshot(gameObject, Color.clear, positionOffset, rotation, scale, width, height);
    }

    /// <summary>
    /// Takes a snapshot of an instantiated GameObject and returns it as a Texture2D.
    /// </summary>
    /// <param name="gameObject">The instantiated GameObject to snapshot.</param>
    /// <param name="backgroundColor">The background color of the snapshot. Can be transparent.</param>
    /// <param name="positionOffset">The position offset relative to the SnapshotCamera that will be applied to the gameObject while taking the snapshot. Its position will be restored after taking the snapshot.</param>
    /// <param name="rotation">The rotation that will be applied to the gameObject while taking the snapshot. Its rotation will be restored after taking the snapshot.</param>
    /// <param name="scale">The scale that will be applied to the gameObject while taking the snapshot. Its scale will be restored after taking the snapshot.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    public Texture2D TakeObjectSnapshot (GameObject gameObject, Color backgroundColor, Vector3 positionOffset, Quaternion rotation, Vector3 scale, int width = 128, int height = 128)
    {
        if (gameObject == null)
            throw new ArgumentNullException("gameObject");
        else if (gameObject.scene.name == null)
            throw new ArgumentException("gameObject parameter must be an instantiated GameObject! If you want to use a prefab directly, use TakePrefabSnapshot instead.", "gameObject");

        // Prepare the gameObject and save its current state so we can restore it later
        GameObjectStateSnapshot previousState = PrepareObject(gameObject, positionOffset, rotation, scale);

        // Take a snapshot
        Texture2D snapshot = TakeSnapshot(backgroundColor, width, height);

        // Restore the gameObject to its previous state
        previousState.Restore();

        // Return the snapshot
        return snapshot;
    }
    #endregion

    #region TakePrefabSnapshot
    /// <summary>
    /// Takes a snapshot of a prefab and returns it as a Texture2D.
    /// 
    /// Uses a completely transparent background and
    /// applies the default position offset, rotation and scale to the prefab while taking the snapshot.
    /// </summary>
    /// <param name="prefab">The prefab to snapshot.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    public Texture2D TakePrefabSnapshot (GameObject prefab, int width = 128, int height = 128)
    {
        return TakePrefabSnapshot(prefab, Color.clear, defaultPositionOffset, Quaternion.Euler(defaultRotation), defaultScale, width, height);
    }

    /// <summary>
    /// Takes a snapshot of a prefab and returns it as a Texture2D.
    /// 
    /// Applies the default position offset, rotation and scale to the prefab while taking the snapshot.
    /// </summary>
    /// <param name="prefab">The prefab to snapshot.</param>
    /// <param name="backgroundColor">The background color of the snapshot. Can be transparent.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    public Texture2D TakePrefabSnapshot (GameObject prefab, Color backgroundColor, int width = 128, int height = 128)
    {
        return TakePrefabSnapshot(prefab, backgroundColor, defaultPositionOffset, Quaternion.Euler(defaultRotation), defaultScale, width, height);
    }

    /// <summary>
    /// Takes a snapshot of a prefab and returns it as a Texture2D.
    /// 
    /// Uses a completely transparent background.
    /// </summary>
    /// <param name="prefab">The prefab to snapshot.</param>
    /// <param name="positionOffset">The position offset relative to the SnapshotCamera that will be applied to the prefab while taking the snapshot.</param>
    /// <param name="rotation">The rotation that will be applied to the prefab while taking the snapshot.</param>
    /// <param name="scale">The scale that will be applied to the prefab while taking the snapshot.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    public Texture2D TakePrefabSnapshot (GameObject prefab, Vector3 positionOffset, Quaternion rotation, Vector3 scale, int width = 128, int height = 128)
    {
        return TakePrefabSnapshot(prefab, Color.clear, positionOffset, rotation, scale, width, height);
    }

    /// <summary>
    /// Takes a snapshot of a prefab and returns it as a Texture2D.
    /// </summary>
    /// <param name="prefab">The prefab to snapshot.</param>
    /// <param name="backgroundColor">The background color of the snapshot. Can be transparent.</param>
    /// <param name="positionOffset">The position offset relative to the SnapshotCamera that will be applied to the prefab while taking the snapshot.</param>
    /// <param name="rotation">The rotation that will be applied to the prefab while taking the snapshot.</param>
    /// <param name="scale">The scale that will be applied to the prefab while taking the snapshot.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    public Texture2D TakePrefabSnapshot (GameObject prefab, Color backgroundColor, Vector3 positionOffset, Quaternion rotation, Vector3 scale, int width = 128, int height = 128)
    {
        if (prefab == null)
            throw new ArgumentNullException("prefab");
        else if (prefab.scene.name != null)
            throw new ArgumentException("prefab parameter must be a prefab! If you want to use an instance, use TakeObjectSnapshot instead.", "prefab");

        // Prepare an instance of the prefab
        GameObject instance = PreparePrefab(prefab, positionOffset, rotation, scale);
        
        // Take a snapshot
        Texture2D snapshot = TakeSnapshot(backgroundColor, width, height);

        // Destroy the instance we created
        DestroyImmediate(instance);

        // Return the snapshot
        return snapshot;
    }
    #endregion

    /// <summary>
    /// Takes a snapshot of whatever is in front of the camera and within the camera's culling mask and returns it as a Texture2D.
    /// </summary>
    /// <param name="backgroundColor">The background color to apply to the camera before taking the snapshot.</param>
    /// <param name="width">The width of the snapshot image.</param>
    /// <param name="height">The height of the snapshot image.</param>
    /// <returns>A Texture2D containing the captured snapshot.</returns>
    private Texture2D TakeSnapshot(Color backgroundColor, int width, int height)
    {
        // Set the background color of the camera
        cam.backgroundColor = backgroundColor;

        // Get a temporary render texture and render the camera
        cam.targetTexture = RenderTexture.GetTemporary(width, height, 24);
        cam.Render();

        // Activate the temporary render texture
        RenderTexture previouslyActiveRenderTexture = RenderTexture.active;
        RenderTexture.active = cam.targetTexture;

        // Extract the image into a new texture without mipmaps
        Texture2D texture = new Texture2D(cam.targetTexture.width, cam.targetTexture.height, TextureFormat.ARGB32, false);
        texture.ReadPixels(new Rect(0, 0, cam.targetTexture.width, cam.targetTexture.height), 0, 0);
        texture.Apply(false);

        // Reactivate the previously active render texture
        RenderTexture.active = previouslyActiveRenderTexture;

        // Clean up after ourselves
        cam.targetTexture = null;
        RenderTexture.ReleaseTemporary(cam.targetTexture);

        // Return the texture
        return texture;
    }
}

snapshot-camera-demo.zip

haha, so many code comments

Can I use this commercially?

@davwen Sure! I forgot to add a license to the gist initially but consider it MIT licensed :)

Thanks for this ! Helped me out a lot on a school project

Hello, thanks for providing this example! Currently, if I take a picture of the prefab and set a resolution of like 1440x1080, I get a very small prefab in the center of the big picture. Is there a way to have it zoom in on the prefab?

Excellent, forked it for some customization 👯

Hey guy! How to use it?

Hi, thx for the code. For a 1x1x1 its really nice, but when i change one side to for example 5, it still takes a snapshot of a 1 x 1 x 1 cube. Somebody know why?

Hey guy! How to use it?

Any luck or hints? Quite the newbie at unity

Very simple Implementation to help others use this:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SnapshotItem : MonoBehaviour
{
    private SnapshotCamera snapshotCamera;
    public GameObject gameObjectToSnapshot;

    void Start()
    {
        snapshotCamera = SnapshotCamera.MakeSnapshotCamera(0);
        Texture2D snapshot = snapshotCamera.TakeObjectSnapshot(gameObjectToSnapshot);
        SnapshotCamera.SavePNG(snapshot);
    }
}

Hey guy! How to use it?

1. Unzip, copy contents in Assests folder to your project's folder "Snapshot" etc. You may need to adjust materials to use your Render Pipeline.
2. Open sample scene "Testscene" inside, you can add your own prefabs.. You may need to change Input to use new Input System, like this

// SnapshotCameraTest.cs
using UnityEngine.InputSystem;
update function:
if (Keyboard.current.spaceKey.wasPressedThisFrame)
//if (Input.GetKeyUp(KeyCode.Space))

3. Create a layer name it "SnapshotLayer", change Camera, the test cubes and your prefabs to this layer.
4. Run scene, take snapshot of test cube by hitting Space. Snapshots are saved in Project-folder/Snapshots.

Hope this helps

well done ty