[Solved, sorta] How to use UnityWebRequest to read local .jpg?

Hey! Sorry I've been pretty irritated lately because of work. And sorry for the huge wall of text as well.

I've been putting aside this project for a month, and now it doesn't work after updating Unity.
I use panoramic shader to put a 360 stereo pic to the skybox. I try using UnityWebRequest:

Code (CSharp):

1. path="C:/test/file.jpg"
2. StartCoroutine(GetText());
3. skybox.SetTexture("_Tex", t);
4.  
5. IEnumerator GetText()
6.         {
7.             using (UnityWebRequest uwr = UnityWebRequestTexture.GetTexture(path))
8.             {
9.                 yield return uwr.SendWebRequest();
10.  
11.                 if (uwr.isNetworkError || uwr.isHttpError)
12.                 {
13.                     Debug.Log(uwr.error);
14.                 }
15.                 else
16.                 {
17.                     // Get downloaded asset bundle
18.                     t = DownloadHandlerTexture.GetContent(uwr);
19.                 }
20.             }
21.         }

BTW I started using WWW because I need to use my script on videos as well, and storing it as url was the best option, and I also want to use the script on android, thus other methods didn't seem efficient. If there is a better way to read .jpgs, I would look after it and see how it works and if it would be good for me.


EDITED because I made progress, tho no progress with UnityWebRequest.

EDIT2: I don't like UWR.

 

UPDATE: I got it working with WWW and the built in panoramic shader.

So my question would be how to make it work with UnityWebRequest, because it did nothing for me... When I use it like WWW it says it's unfinished, and the way it was in the documentation does not work.

Working code:

Code (CSharp):

1. byte[] fileData;
2. WWW reader;
3. reader = new WWW(path);
4. fileData = reader.bytes;
5. t.LoadImage(fileData);
6. skybox.SetTexture("_MainTex", t);

 

I think the problem is this:

Code (CSharp):

1. path="C:/test/file.jpg"

if you are downloading something from the web you have a prefix

http://

or

https://

. If you "download" something from your file system, you also need a prefix:

file://

So, probably it works if you change the line to:

Code (CSharp):

1. path="file://C:/test/file.jpg"

PS: I would not go for WWW and use the UnityWebRequest. There is a reason why unity changed it. And I think the reason is, that the WWW class can cause a memory leak, since it may never be disposed.

PPS: I am not 100% sure but I think you cannot use a Texture2D for a skybox. You need a Cubemap instead.

 

Sadly still doesn't work with file:// added to path.

Texture2D is what panoramic shader skybox material uses, and it works when I use WWW, so that shouldn't be the problem.
EDIT: Yeah, the shader I use is spherical and uses Texture2D. I didn't find anything else that could work the way I want it to. So the only problem is that I can't grasp how to use UnityWebRequest. I only need it because of android (if I get it to work finally), and because or the video player. It's much better to just give it an url, and I found that I could only do it via WWW, so I should be able to do it with UnityWebRequest now.

Also is there a line that can make UnityWebRequest wait, or do I need to use the method above (and in the documentation) every time?

BTW thanks for the response. While it would be logical I didn't think of putting a prefix to the path.

 

I tried file:// I tried file:///, I tried creating a Uri and it still doesn't work. Can anyone share a working code using UnityWebRequest to load a local .jpg? I have no idea what I'm missing.

 

This is code from a project where I use it:

Code (CSharp):

1.             using (UnityWebRequest loader = UnityWebRequestTexture.GetTexture("file://" + FilePath))
2.             {
3.                 yield return loader.SendWebRequest();
4.  
5.                 if (string.IsNullOrEmpty(loader.error))
6.                 {
7.                     _texture = DownloadHandlerTexture.GetContent(loader);
8.                 }
9.                 else
10.                 {
11.                     this.LogErrorFormat("Error loading Texture '{0}': {1}", loader.uri, loader.error);
12.                 }
13.             }

looks pretty much the same as yours.

 

This is so stupid. I had to put the texture change in the if. And it's slow. Is there a way to speed up UnityWebRequest? With WWW it was around a second to load only one .jpg. With UWR it takes 3. That isn't acceptable IMO.

Code (CSharp):

1. IEnumerator GetText()
2.         {
3.             using (UnityWebRequest uwr = UnityWebRequestTexture.GetTexture(path))
4.             {
5.                 yield return uwr.SendWebRequest();
6.  
7.                 if (uwr.isNetworkError || uwr.isHttpError)
8.                 {
9.                     Debug.Log(uwr.error);
10.                 }
11.                 else
12.                 {
13.                     // Get downloaded asset bundle
14.                     t = DownloadHandlerTexture.GetContent(uwr);
15.                     skybox.SetTexture("_MainTex", t);
16.                 }
17.             }
18.         }

I don't like this code at all. I'm really angry how it works now. I get that WWW wasn't great and stuff, but it was acceptable to use. This is outrageous how it looks, and how inefficient it is to load local files with it.

 

Thanks, yeah it's pretty much the same. Even in your code, just to test, I had to put the texture change within the if. And it still takes 2-3 seconds to load just one image. Pretty inefficient, expecially compared to WWW. Can you suggest a better way to load .jpgs?
EDIT: I need a way to load .jpgs that work on Oculus Go as well. I couldn't load .jps there yet, but I'd like to.

EDIT: Another problem is that the script doesn't wait for the dowload to finish (even tho there doesn't have to be any download), thus if I wanna load more pics it takes forever and I can't see the pics, only if I change it after it has finished, manually as of yet.

 

If it takes 2-3 seconds to load, you either have a very slow machine or a huge texture.
In my application I do it like this:
I download the texture from the internet and save it to disk, then dispose the texture. This takes usually less than a second (on mobile).
Later, when I need the texture I load it from disk. Loading it is barely noticeable.

Maybe you have some other problem in your code. Can you show more of the surrounding logic?

 

I really don't get how this works, and don't get why it works this way.

I made a test script, so this is the only code it has. The .jpg is ~4000*4000, 47,3 MB because it's bad quality only for testing. But I'll share the whole code just to be safe:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.Networking;
5. using System;
6.  
7. public class teszt : MonoBehaviour
8. {
9.     private string path;
10.     public Material skybox;
11.     // Start is called before the first frame update
12.     void Start()
13.     {
14.         path = "file:///C:/TEST/test.jpg";
15.         Texture2D t;
16.         t = new Texture2D(2, 2);
17.      
18.         StartCoroutine(GetText());
19.         skybox.SetTexture("_MainTex", t);//This one does nothing
20.  
21.         // Update is called once per frame
22.         void Update()
23.         {
24.  
25.         }
26.         IEnumerator GetText()
27.         {
28.             using (UnityWebRequest uwr = UnityWebRequestTexture.GetTexture(path))
29.             {
30.                 yield return uwr.SendWebRequest();
31.                 if (string.IsNullOrEmpty(uwr.error))
32.                 {
33.                     // Get downloaded asset bundle
34.                     t = DownloadHandlerTexture.GetContent(uwr);
35.                     skybox.SetTexture("_MainTex", t);
36.                     //if I change texture here it works
37.                 }
38.                 else
39.                 {
40.                     Debug.Log(uwr.error);
41.                 }
42.              
43.             }
44.         }
45.     }
46. }

I use latest Unity, 2018.3.5, thus I get a S***load of warnings for using WWW.

So does anyone know why my code is slow?

EDIT: PC isn't a problem, 16GB ram, 1070 TI, processor also pretty nice. I can share the whole specs, but the point is, the computer isn't slow.

 

About why it doesn't work outside of the method:
You are assigning it right after starting the coroutine. At this point the coroutine is idling at the

yield return

statement. In other words: The texture has not yet been loaded because the loading of the texture is not synchronous. So you need to set the texture either after loading and assigning it or you make a callback parameter which is invoked at that point and put the logic in that callback method.

However: 47 MB is a lot it is about 2/3rd of the size a BMP would have with that resolution. The Images I was referring to where less than 2 MB.
Maybe you play a bit with compression to get smaller image sizes. Is the quality acceptable if you compress it via TinyPNG?
Edit: Sorry, just realized that TinyPNG has a maximum image file size which is much too low for you (even if you would pay).

 

I'll be using lot bigger pictures later on. Think about a few hundred MB.

With WWW the same thing was instant, so I guess I shouldn't use URW at all, doesn't seem optimal for the task.

Does this work on android devices? This was the first method I used, but later decided WWW would be better, but URW and WWW seems to be out of the question, so I'll stick with this for the time being, thanks.

 

There is a huge time difference, dunno why. Anyway I'm starting to hate UWR and I won't use it. Hope I won't need to.

 

WWW is deprecated, so yeah you will have to use UWR eventually.
Besides what the Unity rep tells you here is, is that WWW actually calls UWR for you... so either way you're calling UWR directly or WWW does it for you... there shouldn't be a performance difference.

 

If I understand it correctly, the way WWW is implemented now is like this:

Code (CSharp):

1. using (UnityWebRequest uwr = UnityWebRequest.Get(path))
2. {
3.     yield return uwr.SendWebRequest();
4.     if (string.IsNullOrEmpty(uwr.error))
5.     {
6.         t.LoadImage(uwr.downloadHandler.data);
7.     }
8.     else
9.     {
10.         Debug.Log(uwr.error);
11.     }
12. }

maybe you can try this and check if it is faster.
Would be nice if you could measure the time by using a System.Diagnostics.Stopwatch which you start when entering the coroutine method and stop (and log) at the end of the method. Then do that for both approaches and share the results. I would be very interested

 

I did that, here's the conclusion:
UWR method, like in documentation: ~00:00:02.6000000, or ~00:00:01.5000000, or sometimes ~ 00:00:03.0000000 or even 00:00:04.5000000 happened.
WWW method, like I did at the beginning: ~00:00:01.5000000 consistently.
Your method also acts like the UWR method from the documentation, sometimes WWW speed, sometimes slow, but always below 00:00:03.0000000.
Readbytes is just a tiny bit faster than WWW was.

It's not always slower, but inconsistency is even worse than low speed. Seems readbytes is best, but WWW was more than acceptable. UWR seems to be unacceptable from this small experiment. I don't wanna know what would've happened with 300MB files.

 

It can't be faster, yet it is. It may be because the patch screwed something up, and UWR isn't working as intended. Erratic behaviour is never intended, so my guess is that this shouldn't be the case. Yet it is. I ran the program, I got the times, and the program doesn't lie. Doesn't matter how it should be on paper, because I don't use the code on paper, I use it in the program. You don't have to explain. I don't just make this up. It is what it is, I accept it, you should too.

Or you can even conduct your own tests, and maybe even figure out why it happens. I wrote a fresh code, this is the only thing running, so you should get the same results.

 

Code (CSharp):

1. System.Diagnostics.Stopwatch tiem = new System.Diagnostics.Stopwatch();
2. tiem.Start();
3. tiem.Stop();
4. Debug.Log(tiem.Elapsed);

I did just how it was asked by Hosnkobf. Start when entering coroutine, stop when leaving coroutine. For WWW just before creating the WWW, and right after loading the image. Same with file.ReadAllBytes. The problem isn't with speed, there were times when it was the same. Inconsistency is what bugs me, there shouldn't be any. Thus I'll forget UWR even exists, there are a lot more things I don't like about them, so I'll just listen to my gut and never use it. Doesn't matter how good it is, doesn't matter what I'll be doing.

I got my results, I know I'll only be using ReadAllBytes for this. For videos I'll use Uri. I hope that's compatible with video player url source, but that's a test for later. And I hope it'll work on Oculus Go.

EDIT: Also I didn't just run it once. I run it like 20-30 times to get different results. WWW and ReadAllBytes were consistent, always same speed. I made sure I can form an opinion against UWR.

 

Code (CSharp):

1. using System.Collections;
2. using UnityEngine;
3. using UnityEngine.Networking;
4. using System.IO;
5.  
6. public class test : MonoBehaviour
7. {
8.     private string path;
9.     void Start()
10.     {
11.         path = "file:///C:/test/test.jpg";
12.         Texture2D t;
13.         t = new Texture2D(2, 2);
14.  
15.  
16.         System.Diagnostics.Stopwatch tiem = new System.Diagnostics.Stopwatch();
17.         tiem.Start();
18.         StartCoroutine(GetText());
19.  
20.         System.Diagnostics.Stopwatch tiemb = new System.Diagnostics.Stopwatch();
21.         tiemb.Start();
22.         byte[] fileData;
23.         WWW reader;
24.         reader = new WWW(path);
25.         fileData = reader.bytes;
26.         t.LoadImage(fileData);
27.         tiemb.Stop();
28.         Debug.Log("WWW"+tiemb.Elapsed);
29.  
30.         System.Diagnostics.Stopwatch tiemc = new System.Diagnostics.Stopwatch();
31.         tiemc.Start();
32.         StartCoroutine(GT2());
33.  
34.  
35.         System.Diagnostics.Stopwatch tiemd = new System.Diagnostics.Stopwatch();
36.         tiemd.Start();
37.         path = "C:/test/test.jpg";
38.         fileData = File.ReadAllBytes(path);
39.         t.LoadImage(fileData);
40.         tiemd.Stop();
41.         Debug.Log("readbytes"+tiemd.Elapsed);
42.  
43.  
44.         // Update is called once per frame
45.         void Update()
46.         {
47.  
48.         }
49.         IEnumerator GetText()
50.         {
51.             using (UnityWebRequest uwr = UnityWebRequestTexture.GetTexture(path))
52.             {
53.                 yield return uwr.SendWebRequest();
54.                 if (string.IsNullOrEmpty(uwr.error))
55.                 {
56.                     // Get downloaded asset bundle
57.                     t = DownloadHandlerTexture.GetContent(uwr);
58.                     tiem.Stop();
59.                     Debug.Log("UWR"+tiem.Elapsed);
60.                 }
61.                 else
62.                 {
63.                     Debug.Log(uwr.error);
64.                 }
65.                
66.             }
67.         }
68.         IEnumerator GT2()
69.         {
70.             using (UnityWebRequest uwr = UnityWebRequest.Get(path))
71.             {
72.                 yield return uwr.SendWebRequest();
73.                 if (string.IsNullOrEmpty(uwr.error))
74.                 {
75.                     t.LoadImage(uwr.downloadHandler.data);
76.                     tiemc.Stop();
77.                     Debug.Log("forumguy" + tiemc.Elapsed);
78.                 }
79.                 else
80.                 {
81.                     Debug.Log(uwr.error);
82.                 }
83.             }
84.  
85.         }
86.     }
87. }

I know you think I'm actually retarded, but a simple speed check is something I can do. I created 4 different timers so they can work simultaneously.

Do the test yourself if you want, but I don't really want to use UWR anymore, whatever the outcome of any test.

I also have Unity 2018.3.5, which may be important information. I had to rewrite my code because of the update, so yeah. I'm happy.

 

I want it to wait, and not to run in the background, because I want to see the image. I didn't find this wait function you shared now, so thanks. I'll may still try to use it.

Thanks, I'll still stick to ReadAllBytes, because I don't want a coroutine, I don't want background work to be done. I'm a simple man with simple needs: to load an image, then show the image. I could easily do that with WWW, but with UWR I couldn't find how to do that, and even now I found it too... Well the code is ugly IMO, and bigger. Which I hate.

 

Wow, you are using local methods. I was not aware that unity already supports that!
However, I refactored your code to get more reliable test results:

Code (CSharp):

1.  
2. using System.Collections;
3. using UnityEngine;
4. using UnityEngine.Networking;
5. using System.IO;
6.  
7. public class TestTime : MonoBehaviour
8. {
9.     private const string path = "C:/test/test.jpg";
10.     private const string pathWithPrefix = "file://C:/test/test.jpg";
11.  
12.     IEnumerator Start()
13.     {
14.         const int iterations = 100;
15.         yield return StartCoroutine(TestTimeRoutine("UWR Texture",  iterations, TestTimeForUwrTexture));
16.         yield return StartCoroutine(TestTimeRoutine("UWR Bytes",    iterations, TestTimeForUwrBytes));
17.         yield return StartCoroutine(TestTimeRoutine("WWW Texture",  iterations, TestTimeWWWTexture));
18.         yield return StartCoroutine(TestTimeRoutine("WWW Bytes",    iterations, TestTimeWWWBytes));
19.         yield return StartCoroutine(TestTimeRoutine("Direct Load",  iterations, TestTimeDirectLoad));
20.     }
21.  
22.     IEnumerator TestTimeRoutine(string testTitle, int iterations, System.Func<IEnumerator> innerRoutine)
23.     {
24.         System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
25.         watch.Start();
26.         for (int i = 0; i < iterations; i++)
27.         {
28.             yield return StartCoroutine(innerRoutine());
29.         }
30.         watch.Stop();
31.  
32.         Debug.LogFormat("{0} - iterations: {1} - total time: {2} ms - average time: {3} ms",
33.             testTitle, iterations, watch.ElapsedMilliseconds, watch.ElapsedMilliseconds / iterations);
34.     }
35.  
36.     IEnumerator TestTimeForUwrTexture()
37.     {
38.         Texture tex = null;
39.         using (UnityWebRequest uwr = UnityWebRequestTexture.GetTexture(pathWithPrefix))
40.         {
41.             yield return uwr.SendWebRequest();
42.             if (string.IsNullOrEmpty(uwr.error))
43.             {
44.                 // Get downloaded asset bundle
45.                 tex = DownloadHandlerTexture.GetContent(uwr);
46.             }
47.             else
48.             {
49.                 Debug.Log(uwr.error);
50.             }
51.  
52.         }
53.     }
54.  
55.  
56.     IEnumerator TestTimeForUwrBytes()
57.     {
58.         Texture2D tex = new Texture2D(2, 2);
59.         using (UnityWebRequest uwr = UnityWebRequest.Get(pathWithPrefix))
60.         {
61.             yield return uwr.SendWebRequest();
62.             if (string.IsNullOrEmpty(uwr.error))
63.             {
64.                 tex.LoadImage(uwr.downloadHandler.data);
65.             }
66.             else
67.             {
68.                 Debug.Log(uwr.error);
69.             }
70.         }
71.     }
72.  
73.     IEnumerator TestTimeWWWTexture()
74.     {
75.         Texture2D tex = null;
76.         WWW reader = new WWW(pathWithPrefix );
77.         yield return reader;
78.      
79.         tex = reader.texture;
80.     }
81.  
82.     IEnumerator TestTimeWWWBytes()
83.     {
84.         Texture2D tex = new Texture2D(2, 2);
85.         WWW reader = new WWW(pathWithPrefix );
86.         yield return reader;
87.  
88.         byte[] data = reader.bytes;
89.         tex.LoadImage(data);
90.     }
91.  
92.     IEnumerator TestTimeDirectLoad()
93.     {
94.         Texture2D tex = new Texture2D(2, 2);
95.         byte[] data = File.ReadAllBytes(path);
96.         tex.LoadImage(data);
97.         yield break;
98.     }
99.  
100. }

Note: not tested by myself.

Edit: fixed WWW method which was had a copy paste problem

 

The code I posted does it one at a time.

 

How do we access an image from a shared folder in this scenario? Lets us say two machines are connected in a private network. Unity application is running in one machine and there are images that need to be accessed from the second machine. Will UnityWebRequest still work in this scenario?

 

OH MY GOD FINALLY!!!!!!!!!!!!!!!!!!!! This worked for my needs. I never saw this reference in docs at all. Thank you!!!!

 

I know I am coming late to the party... but after experimenting with LoadImage() and Webrequest Get.... the code above is by far the best one when it comes to speed and it works with android...

Just one remark for memory management, id you add the uwr.Dispose(); after you assigned the texture, it will help you loads with the memory management in android.