You simply need to do your editing (and shot design) carefully so that the effect is “seamless.”
For instance, you might arrange for the camera to follow a path at a certain rate. (The camera, and its path, is in a single linked asset-file. In the same file you might place “empties” which correspond to key positions, for props and so-forth, which must be the same throughout.) You can now do a “fly-through” using dummy-objects that are parented to each empty. “Stamp” your fly-through with frame numbers and note the precise frame-numbers where each cut will occur.
Next, you construct each set, once again in separate linked files, using the empties to help you precisely position key objects that will be seen in each scene. (Parent them to the linked empties.)
Your lighting design, insofar as possible, should also be a linked-asset, so that you know that the lighting will be consistent from one shot to the next.
You can now, again with creative linking of assets, produce a blend-file that (perhaps in a group of “scenes,” for convenience) is used to OpenGL-preview render each “strip of film,” including a frame-number and filename “stamp” on each one. Go ahead and “render the whole damned thing,” as though the complete fly-through was occurring on each set in turn. (It’s fast. You can do this.) Stamp each strip with frame-number and file-name.
Now, put on your Editor’s cap and cut the strips together at the chosen positions. By tying your camera to a path, you have the perfect “motion-control rig” to work with. Notice that you can “slide” the cut-points back and forth, along these identical-length strips of film, and the transition at any point will still be seamless.
(At least with BI renders, the lighting in a Preview render will also be consistent. You should measure the illumination at the key points, in each strip, to be sure that they appear consistent and seamless in Preview. Look at the histogram; use the eyedropper to sample (R,G,B) values. Careful attention to detail now will save much time later. When you think you’ve got it, pull a one-frame final-render at the transition-points and examine them again.)
- Now, it’s time to let the client see something, and to become involved now(!) in what happens next.
OpenGL Preview renders will be exact stand-ins for renders produced by other methods. (Sometimes, they can be “final shots.”) You can now present this film to the client for review, knowing that it is inevitable that editing recommendations will now be made … now that the client can see what you are talking about. This is why we’ve delayed final-render.
The “timing and pacing” of the sequence will be very important, perhaps tied to music (or, vice-versa). The film will need to “hit” particular “beats.” There will be story-telling decisions that are made here. However, since you have complete renderings of each strip of film, you can quickly accomplish this with editing, either using Blender VSE or some other video-editing tool. (I use Final Cut Pro.)
Practice this so that you can do it in front of the customer.
Your editing process is very similar to what they do in television, punching one camera-button after the other to [CUT TO], at that instant, from one cam that is following the same action to another. Because all of your quick-renders are of identical complete fly-thrus, you can accommodate the finest of editing decisions … quickly.
When you finally reach “final cut,” you can now make a list of the frame-numbers that you actually need from each strip, and final-render only those frames. (Use a “frame per file” format such as OpenEXR.) Drop these into your final-cut edit in place of the stand-ins, one strip at a time, and the film is done. The customer receives a final render of exactly what he has already agreed-to.