使用Unity3D和Vuforia的Android 4.1.2上的相机为黑色

Question

The company I work is building an android application with vuforia(version 5.x) and Unity3D(version 5.3.5f1 Personal) integration.

In newest android devices the camera is opening ok but We're facing problem in older devices like Samsung Galaxy S2(4.1.2). When the device open the camera via vuforia the screen is black and if we try to take a picture the image is obviously black as well.

My activity is only instantiating the unity player and it is like code below:

public class MainActivity extends AppCompatActivity {

protected UnityPlayer mUnityPlayer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    getWindow().setFormat(PixelFormat.RGBX_8888); // <--- This makes xperia play happy
    mUnityPlayer = new UnityPlayer(this);
    setContentView(mUnityPlayer);
    mUnityPlayer.requestFocus();
}

public void onImageSaved(final String path) {
    final Intent intent = new Intent(MainActivity.this, CameraPreviewActivity.class);
    final Bundle bundle = new Bundle();
    bundle.putString("IMAGE_PATH", path);
    intent.putExtras(bundle);
    startActivity(intent);
}

public void onImageSavedError(final String message) {
    UnityPlayer.currentActivity.runOnUiThread(new Runnable() {

        @Override
        public void run() {
            Log.e("Teste", message);
        }
    });
}

// Quit Unity
@Override protected void onDestroy ()
{
    mUnityPlayer.quit();
    super.onDestroy();
}

// Pause Unity
@Override protected void onPause()
{
    super.onPause();
    mUnityPlayer.pause();
}

// Resume Unity
@Override protected void onResume()
{
    super.onResume();
    mUnityPlayer.resume();
}

// This ensures the layout will be correct.
@Override public void onConfigurationChanged(Configuration newConfig)
{
    super.onConfigurationChanged(newConfig);
    mUnityPlayer.configurationChanged(newConfig);
}

// Notify Unity of the focus change.
@Override public void onWindowFocusChanged(boolean hasFocus)
{
    super.onWindowFocusChanged(hasFocus);
    mUnityPlayer.windowFocusChanged(hasFocus);
}

// For some reason the multiple keyevent type is not supported by the ndk.
// Force event injection by overriding dispatchKeyEvent().
@Override public boolean dispatchKeyEvent(KeyEvent event)
{
    if (event.getAction() == KeyEvent.ACTION_MULTIPLE)
        return mUnityPlayer.injectEvent(event);
    return super.dispatchKeyEvent(event);
}

// Pass any events not handled by (unfocused) views straight to UnityPlayer
@Override public boolean onKeyUp(int keyCode, KeyEvent event)     { return mUnityPlayer.injectEvent(event); }
@Override public boolean onKeyDown(int keyCode, KeyEvent event)   { return mUnityPlayer.injectEvent(event); }
@Override public boolean onTouchEvent(MotionEvent event)          { return mUnityPlayer.injectEvent(event); }
/*API12*/ public boolean onGenericMotionEvent(MotionEvent event)  { return mUnityPlayer.injectEvent(event); }

@Override
public void onBackPressed() {
    finish();
}

}

The vuforia is responsible for opening the camera and starting tracking the image targets while unity3D will render a 3D image with animation and responsible for taking the picture.

In unity project we have developed a button to take a picture and a function thats gonna save the image in an android directory. Its is script was done in C# and its implementation is as follow below:

IEnumerator TakeSnapshot()
{
    yield return new WaitForEndOfFrame();
    Texture2D snap = new Texture2D(Screen.width,Screen.height);
    Camera camera = Camera.current;

    if (rotation != null)
    {
        camera.transform.rotation = rotation.Value;
    }

    if (position != null)
    {
        camera.transform.position = position.Value;
    }

    camera.Render();
    RenderTexture.active = camera.targetTexture;
    snap.ReadPixels(new Rect(0,0,Screen.width,Screen.height),0,0);
    snap.Apply();
    RenderTexture.active = null;

    byte[] bytes = snap.EncodeToJPG();
    DestroyObject(snap);

    string path = Application.persistentDataPath + "/MyAppPath/";
    if(!System.IO.Directory.Exists(path)){
        System.IO.Directory.CreateDirectory(path);
    }

    string filename = fileName(Convert.ToInt32(snap.width), Convert.ToInt32(snap.height));
    path = path + filename;
    System.IO.File.WriteAllBytes(path, bytes);

    using (var actClass = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
    {
        var jo = actClass.GetStatic<AndroidJavaObject>("currentActivity");

        if (jo == null) {
            Debug.Log ("jo is null");
        } else {
            jo.Call("onImageSaved", path);
        }
    }
}

The main goal of this post is try to understand why camera is black only in older devices since it worked fine in newer one. Also I would like to highlight that openGL may not be a problem since I have already tested the application in older devices like Samsung Galaxy S2 using sinogen 5.1. The current openGL version that unity project is being exported is openGL2. Thanks in advance.

Answer 1

Try this code:

public string deviceName;
WebCamTexture wct;
void Start ()
{
    WebCamDevice[] devices = WebCamTexture.devices;
    deviceName = devices[0].name;
    wct = new WebCamTexture(deviceName, 400, 300, 12);
    GetComponent<Renderer> ().material.mainTexture = wct;
    wct.Play();
}