Select the Clouds1 composition in the Project Window and hit Ctrl/Cmd + D four times. Now open the Clouds2 composition, select the Cloud layer, hit F3 to open its Effect Window, and change the value of Evolution. Do this with the CloudMASK layer, too.
Repeat this for all other duplicated Clouds compositions, each time setting a different evolution value. This is done so each layer of cloud has a different texture. Once you’re done with the Clouds compositions, you should have five compositions named Clouds1, Clouds2, Clouds3 and so on, each being a different fractal.
Now drag all five Clouds compositions in the main Heaven composition under the camera layer, convert them to 3D layers, and set their Screen Mode to Screen. Select them all, and press P to expand their Position property. Now, give each one a different Z Position value from -300 to -700, to create a more believable 3D space.
Add an opacity keyframe for all five Clouds layers at the beginning of the timeline. Now go to frame 0:00:00:10, and set their Opacity to 0 per cent. On the Composition Window, change the view from Active Camera to Left, go to the first frame of the video, and slowly drag the Time Indicator to the right.
What you’ll see is the camera moving through each of the Clouds layers, towards the ground. Move each Clouds layer’s pair of Opacity keyframes to the point in time where the camera passes through them, so that by the time it does, they’ve already disappeared, remembering that opacity is set to 0 per cent.