Camera destroy issue. version #2.1.1

[perunvolodymyr]

Hello, I encountered a problem with destroying the camera when closing the window. The problematic area and how to solve it:

Problem:

override fun destroy() {
        super.destroy()

        engine.safeDestroyCamera(camera)
    }

StackTrace:

java.lang.NullPointerException
             	at io.github.sceneview.components.CameraComponent$DefaultImpls.getCamera(CameraComponent.kt:30)
             	at io.github.sceneview.node.CameraNode.getCamera(CameraNode.kt:27)
             	at io.github.sceneview.node.CameraNode.destroy(CameraNode.kt:330)
             	at io.github.sceneview.SceneKt$rememberCameraNode$$inlined$rememberNode$1$1.dispose(Effects.kt:498)
             	at androidx.compose.runtime.DisposableEffectImpl.onForgotten(Effects.kt:87)
             	at androidx.compose.runtime.CompositionImpl$RememberEventDispatcher.dispatchRememberObservers(Composition.kt:1276)
             	at androidx.compose.runtime.CompositionImpl.applyChangesInLocked(Composition.kt:984)
             	at androidx.compose.runtime.CompositionImpl.applyChanges(Composition.kt:1005)
             	at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$1.invoke(Recomposer.kt:639)
             	at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$1.invoke(Recomposer.kt:551)
             	at androidx.compose.ui.platform.AndroidUiFrameClock$withFrameNanos$2$callback$1.doFrame(AndroidUiFrameClock.android.kt:41)
             	at androidx.compose.ui.platform.AndroidUiDispatcher.performFrameDispatch(AndroidUiDispatcher.android.kt:109)
             	at androidx.compose.ui.platform.AndroidUiDispatcher.access$performFrameDispatch(AndroidUiDispatcher.android.kt:41)
             	at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.doFrame(AndroidUiDispatcher.android.kt:69)
             	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:970)
             	at android.view.Choreographer.doCallbacks(Choreographer.java:796)
             	at android.view.Choreographer.doFrame(Choreographer.java:727)
             	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:957)
             	at android.os.Handler.handleCallback(Handler.java:938)
             	at android.os.Handler.dispatchMessage(Handler.java:99)
             	at android.os.Looper.loop(Looper.java:223)
             	at android.app.ActivityThread.main(ActivityThread.java:7656)
             	at java.lang.reflect.Method.invoke(Native Method)
             	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
             	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
             	Suppressed: kotlinx.coroutines.internal.DiagnosticCoroutineContextException: [androidx.compose.runtime.PausableMonotonicFrameClock@8b855a5, androidx.compose.ui.platform.MotionDurationScaleImpl@332ed7a, StandaloneCoroutine{Cancelling}@766792b, AndroidUiDispatcher@1cee188]

Solution:

class CameraNode2(engine: Engine) : CameraNode(engine = engine) {

    init {
        transform = Transform(position = Vector3.back().toFloat3())
        setExposure(
            aperture = 16.0f,
            sensitivity = 100.0f,
            shutterSpeed = 1.0f / 125.0f
        )
    }

    override fun destroy() {
        engine.safeDestroyCamera(camera)

        runCatching { parent = null }
        engine.safeDestroyTransformable(entity)
        engine.safeDestroyEntity(entity)
    }
}

@Composable
fun rememberCameraNode2(engine: Engine): CameraNode =
    rememberNode {
        CameraNode2(engine)
    }
{class CameraNode2(engine: Engine) : CameraNode(engine = engine) {

    init {
        transform = Transform(position = Vector3.back().toFloat3())
        setExposure(
            aperture = 16.0f,
            sensitivity = 100.0f,
            shutterSpeed = 1.0f / 125.0f
        )
    }

    override fun destroy() {
        engine.safeDestroyCamera(camera)

        runCatching { parent = null }
        engine.safeDestroyTransformable(entity)
        engine.safeDestroyEntity(entity)
    }
}

@Composable
fun rememberCameraNode2(engine: Engine): CameraNode =
    rememberNode {
        CameraNode2(engine)
    }
}

Code how use it:

val engine = rememberEngine()
val camera = rememberCameraNode2(engine)
val cameraManipulator = rememberCameraManipulator(
            creator = {
                Manipulator.Builder()
                    .orbitHomePosition(Position(x = 1F, y = 1.5F, z = 7F))
                    .targetPosition(boxShape.centerPosition)
                    .orbitSpeed(0.005F, 0.0F)
                    .zoomSpeed(0.05f)
                    .build(Manipulator.Mode.ORBIT)
            }
        )
Scene(
...
engine = engine,
cameraNode = camera,
cameraManipulator = cameraManipulator,
...
)

[Denis-Makovskyi-ImproveIT]

Yep, the problem is in CameraNode#destory method.
CameraNode invokes super class destory method first and there Entity is destorying. So when after super call CameraNode calls engine.safeDestroyCamera(camera), at this moment Entity is already destoryed, but the Camera instance takes from the Engine which is doesn't exist anymore.
@ThomasGorisse

[ThomasGorisse]

Good catch.
Can you create a PR where the super.destroy() is called after the camera one?
Thanks @Denis-Makovskyi-ImproveIT

[ThomasGorisse]

Fixed in 2.2.0

[andresteves]

Still getting this issue on 2.3.0...