title: "Fading in" new layers in Keras
body: <p>I'm trying to implement <a href="https://arxiv.org/pdf/1710.10196.pdf" rel="nofollow noreferrer">this</a> paper in Keras, with a tensorflow backend.</p>
  
  <p>In my understanding, they progressively grow a GAN, fading in additional blocks of layers as the model is trained. New layers are faded in linearly over iterations.</p>
  
  <p>I'm not sure how to introduce the "fading in" they used.</p>
  
  <p>To do this Keras, I'm thinking I'll probably need a Lambda layer -- but that's about as much as I know. </p>
  
  <p>Any suggestions?</p>
  
  <p>Thanks!</p>