There are many ways to make your animation shot lite! Like using proxy reference, maybe turning off useless reference object. Another option can be using Z-imagePlane for substituting with real objects, idea can be implemented in pipeline special for heavy Background scene so that animator could breath. (or let other breath, goddamn these ever complaining animators).
Here we go, I would take a lame example to explain my point. Here is the scene with few objects, a plane, cube and sphere.Let’s suppose sphere is our hero object and we gonna animate it. And rest two objects are high poly objects.
So now we need to hide the sphere in scene,also its time to lock down the camera in scene whether it’s animated or not just lock it.
Then go to render settings and set the output resolution to same as resolution gate of camera. Select the right camera ,Now check the “depth channel (Z-depth)” option as in image below, make sure image format is set to maya iff. Hide the primary object that we wish to animate.Now batch render out scene in your proj directory.
Hide the objects that we have render out and UnHide our animatable objects. Now import imagePlane from viewPort “view >imagePlane >import imageplane” and in imagePlane options check “Fit to resolution gate” and in depth settings check “Use depth map”.
what maya did is using Z-depth it composite out the objects in viewport. since z-depth contains depth information we can freely move our animated object with depth information around other objects (which we now have hidden).So now our scene will also be light as it now doesn’t need to draw polygon again.
(in above image only sphere is there yet you can see polySphere is behind cube,z-depth in action)