Question Error: You are trying to upload data for texture created with external texture pointer

Hi,
I,m working on the SteamVR_TestTrackedCamera script... I want to make the central pixel coloured ... Here is the code ...

Code (CSharp):

1. //======= Copyright (c) Valve Corporation, All rights reserved. ===============
2. using UnityEngine;
3. namespace Valve.VR.Extras
4. {
5.     public class SteamVR_TestTrackedCamera : MonoBehaviour
6.     {
7.         public Material material;
8.         public Transform target;
9.         public bool undistorted = true;
10.         public bool cropped = true;
11.         private void OnEnable()
12.         {
13.             // The video stream must be symmetrically acquired and released in
14.             // order to properly disable the stream once there are no consumers.
15.             SteamVR_TrackedCamera.VideoStreamTexture source = SteamVR_TrackedCamera.Source(undistorted);
16.             source.Acquire();
17.             // Auto-disable if no camera is present.
18.             if (!source.hasCamera)
19.                 enabled = false;
20.         }
21.         private void OnDisable()
22.         {
23.             // Clear the texture when no longer active.
24.             material.mainTexture = null;
25.             // The video stream must be symmetrically acquired and released in
26.             // order to properly disable the stream once there are no consumers.
27.             SteamVR_TrackedCamera.VideoStreamTexture source = SteamVR_TrackedCamera.Source(undistorted);
28.             source.Release();
29.         }
30.         private void Update()
31.         {
32.             SteamVR_TrackedCamera.VideoStreamTexture source = SteamVR_TrackedCamera.Source(undistorted);
33.             Texture2D texture = source.texture;
34.             if (texture == null)
35.             {
36.                 return;
37.             }
38.             // Apply the latest texture to the material.  This must be performed
39.             // every frame since the underlying texture is actually part of a ring
40.             // buffer which is updated in lock-step with its associated pose.
41.             // (You actually really only need to call any of the accessors which
42.             // internally call Update on the SteamVR_TrackedCamera.VideoStreamTexture).
43.    
44.             material.mainTexture = texture;   //associa il material alla texture per farmi vedere il mondo esterno proiettato sul quad
45. // Here the part of code I have added ----------------------------------
46.            Color32 color = new Color32(0, 255, 0, 0);
47.        
48.            texture.SetPixel(texture.width / 2, texture.height / 2, color); //equivalente a dire texture.SetPixel(64, 64, color);
49.            texture.Apply();
50. //-----------------------------------------------------------------------------------
51.             // Adjust the height of the quad based on the aspect to keep the texels square.
52.             float aspect = (float)texture.width / texture.height;
53.                 // The undistorted video feed has 'bad' areas near the edges where the original
54.                 // square texture feed is stretched to undo the fisheye from the lens.
55.                 // Therefore, you'll want to crop it to the specified frameBounds to remove this.
56.                 if (cropped)
57.                 {
58.                     VRTextureBounds_t bounds = source.frameBounds;
59.                     material.mainTextureOffset = new Vector2(bounds.uMin, bounds.vMin);
60.                     float du = bounds.uMax - bounds.uMin;
61.                     float dv = bounds.vMax - bounds.vMin;
62.                     material.mainTextureScale = new Vector2(du, dv);
63.                     aspect *= Mathf.Abs(du / dv);
64.                 }
65.                 else
66.                 {
67.                     material.mainTextureOffset = Vector2.zero;
68.                     material.mainTextureScale = new Vector2(1, -1);
69.                 }
70.                 target.localScale = new Vector3(1, 1.0f / aspect, 1);
71.                 // Apply the pose that this frame was recorded at.
72.                 if (source.hasTracking)
73.                 {
74.                     SteamVR_Utils.RigidTransform rigidTransform = source.transform;
75.                     target.localPosition = rigidTransform.pos;
76.                     target.localRotation = rigidTransform.rot;
77.                 }
78.             }
79.         }
80.     }
81.  

However when I run the code I can't see the coloured pixel and the console gives me this error:

You are trying to upload data for texture created with external texture pointer
UnityEngine.Texture2D:Apply()
Valve.VR.Extras.SteamVR_TestTrackedCamera:Update() (at Assets/SteamVR/Extras/SteamVR_TestTrackedCamera.cs)

Can someone help me solve? Thank you.

 

I believe SteamVR uses external texture for its camera texture:
https://docs.unity3d.com/ScriptReference/Texture2D.CreateExternalTexture.html

Try to copy the texture and modify the copy instead.

 

Hi, thank you for your answer. I tried to make as you have suggested but I continue not the see the central pixel modified