title: Android ConstraintLayout particle animation elevation
body: <p>I have a big issue , I'm trying to put particle animation in background 
  I'm using the library : <a href="https://github.com/plattysoft/Leonids" rel="nofollow noreferrer">https://github.com/plattysoft/Leonids</a></p>
  
  <p>Confettis's Animation is on my screen perfectly but it's in foreground and I wanted it to be on background behind my ImageView !</p>
  
  <p>I tried set elevation of my ImageView but animation stay in foreground</p>
  
  <p>I have my SplashScreen.xml with Constraintlayout :</p>
  
  <pre><code>&lt;android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
  
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:id="@+id/bg_splash"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="@drawable/bg_splashscreen"&gt;
  
  
  &lt;ImageView
      android:id="@+id/logo_text"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_marginBottom="8dp"
      android:layout_marginEnd="36dp"
      android:layout_marginStart="37dp"
      android:layout_marginTop="8dp"
      android:src="@drawable/logo"
      android:elevation="4dp"
      app:layout_constraintBottom_toTopOf="@+id/guideline2"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintHorizontal_bias="0.0"
      app:layout_constraintHorizontal_weight="0.1"
      app:layout_constraintStart_toStartOf="parent"
      app:layout_constraintTop_toTopOf="@+id/guideline"
      app:layout_constraintVertical_weight="0.1"
      tools:ignore="ContentDescription" /&gt;
  
  &lt;android.support.constraint.Guideline
      android:id="@+id/guideline"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:orientation="horizontal"
      app:layout_constraintGuide_percent="0.26371" /&gt;
  
  &lt;android.support.constraint.Guideline
      android:id="@+id/guideline2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:orientation="horizontal"
      app:layout_constraintGuide_percent="0.42074" /&gt;
  &lt;/android.support.constraint.ConstraintLayout&gt;
  </code></pre>
  
  <p>And my confetti animation is called basically in my onCreate method of my SplashScreen activity.
  Here is the method called in my Splashscreen Activity : </p>
  
  <pre><code>fun particleConfettiAnimation(fromActivity: Activity?) {
  
          if (fromActivity == null){ return }
  
          ParticleSystem(fromActivity, 80, R.drawable.confetti, 10000)
              .setSpeedModuleAndAngleRange(0f, 0.3f, 0, 0)
              .setRotationSpeed(144f)
              .setAcceleration(0.00035f, 100)
              .emit(100, -100, 5)
       }
  </code></pre>
  
  <p>EDIT : I think I understood that the hierarchy in ConstraintLayout is : what is created last is on foreground compared to other elements created before so that can explain why the animation is in foreground compared to my ImageView</p>
  
  <p>But how can I fix this ? 
  Hope that will be clear enough , thanks !</p>