user21775: I'm using Adobe After Effects. I have a composition with several layers. One layer consists of an image which is shown for around 20s. At time point 10s I would like to bring the image to the foreground (relative to the other layers) and at time point 15s I would like to move it again to the background.
How can I achieve this?

user4426: After Effects by default works in 2D, but you can change a layer so that it can be moved in 3D space.  The layer itself is still flat, but (like a postcard moving through space) it can be positioned using x,y and z coordinates where z is depth.
This tutorial explains it well:
https://helpx.adobe.com/after-effects/how-to/position-2d-layers-in-3d-space.html
You can also do full 3D work in After Effects, but I think this should cover your question.
Alternatively if you want to only work in 2D, sometimes I duplicate a layer, and have one layer at the bottom of my stack, and the duplicate layer at the top, so that when I need to change its apparent "depth", I make one layer invisible and make the other layer visible (by keyframing the Opacity property).

21775: <p>I'm using Adobe After Effects. I have a composition with several layers. One layer consists of an image which is shown for around 20s. At time point 10s I would like to bring the image to the foreground (relative to the other layers) and at time point 15s I would like to move it again to the background.</p>

<p>How can I achieve this?</p>
 4426: <p>After Effects by default works in 2D, but you can change a layer so that it can be moved in 3D space.  The layer itself is still flat, but (like a postcard moving through space) it can be positioned using x,y and z coordinates where z is depth.</p>

<p>This tutorial explains it well:
<a href="https://helpx.adobe.com/after-effects/how-to/position-2d-layers-in-3d-space.html" rel="nofollow noreferrer">https://helpx.adobe.com/after-effects/how-to/position-2d-layers-in-3d-space.html</a></p>

<p>You can also do full 3D work in After Effects, but I think this should cover your question.</p>

<p>Alternatively if you want to only work in 2D, sometimes I duplicate a layer, and have one layer at the bottom of my stack, and the duplicate layer at the top, so that when I need to change its apparent "depth", I make one layer invisible and make the other layer visible (by keyframing the Opacity property).</p>
