In this article I’d like to compare a few different previs techniques and figure out which is the most efficient. Previs comes in many forms, including shot lists, storyboards, animatics, “toy commercials”, 3D previsualizations, physical blocking, virtual production, and anything in between. All these forms serve the same purpose: to prototype the filmmaker’s vision and to communicate it to others.
Wikipedia provides a good definition of the word “prototype”:
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.
What I want to stress here is that people create prototypes in virtually every human endeavor. Prototypes are so common that almost every profession calls prototyping by some other name: thumbnails (art), blocking (theater), software prototyping, rapid prototyping (industrial design), scale model (architecture), paper prototyping (game design), outlining (writing), etc. And as almost anyone in any field will tell you, creating and iterating prototypes is the most creative part of creating anything. The rest is just implementation.
Previs is a kind of prototype for filmmakers and animators. A previs is created to quickly and cheaply puzzle out most of the important aspects of a sequence, especially the action, camera moves, and editing. It is a video and audio plan. Personally, I’d never show up to the set without a previs. Frankly, the set is NOT the place to get creative–it’s the place to get shots done, because time is money on the set.
When creating a previs, it’s important to be able to iterate ideas quickly and to keep the process fun and fresh. But some previs techniques are more efficient than others. Which is best? I’ve made a list of the common previs techniques here. I’ve also (arbitrarily) rated them on their fun factor (is it fun working this way?) and relative efficiency (ability to iterate quickly) from 1 to 5, with 5 being the best score.
Shot Lists
This is the simplest kind of previs. Just make a list of the shots you’ll need. For some films a shot list is more than adequate. But for VFX films and animations, shot lists don’t convey enough information.
Requirements: pen and paper. Fun factor: 1. Efficiency: 5.
Storyboards/Animatics
Storyboards are the traditional form of previs, still preferred over other methods at some major studios, like Pixar. A good storyboard can convey a lot of information. An animatic, which is a storyboard edited together into a video with temp sound, can convey even more.
However, it’s probably not the most efficient way to make iterations. For example, making a camera change requires making a new drawing. Even you draw very fast, it’s still a relatively slow method compared to some of the others.
Requirements: pen and paper, some drawing ability. Fun factor: 3. Efficiency: 3.
3D Animatics
A 3D animatic is created inside a 3D program by keyframing CG characters. Sometimes “stepped” keyframes are used for a more stop-motion look. This is the technique I used to create the previs for PRIMITIVE. From experience, I can tell you that this technique sucks. It is dead slow and NOT fun. I would not recommend it to anyone and I certainly would NEVER use this technique again! (Only exception is when the characters are almost static, like interview shoots.)
I’ve also seen 2.5D animatics, which is when you draw on flat “alpha cards”, arrange them in a 3D program and then do a virtual camera pass. (See the Ratatouille special features for an example.) Again, I can’t imagine the 2.5D animatic technique being very efficient either.
Requirements: 3D program and ability to model, rig, and animate characters. Fun factor: 1. Efficiency: 1.
“Toy Commercials”
This is a wonderful previs technique I recently discovered. Surprisingly, I’ve never seen this technique used in film production. (If you find any examples, please let me know!) But apparently many video game companies use it to prototype game levels. Here’s an example:
What fun! The idea is to take a completely analog 3D approach. You can start with a sandbox. Literally a box filled with sand placed on a table. And fill it with toys, cardboard cutouts for buildings, and custom models made out of polymer oven bake clay (Sculpey). Then simply play with your “toys” and record the action with a small camera. I can’t possibly see a reason why this wouldn’t be fun and efficient. It’s also a good technique to use when you have no friends (like me) to help you with the previs. If you have kids, maybe you can get them in on the action!
I wish I knew about this technique when I was making the previs for PRIMITIVE. But back then I was so inundated with “digital or die” that I never even considered doing things in an analog way. I can only imagine now all the time I would have saved by simply pouring water over a toy Neanderthal’s head, instead of making a freaking fluid simulation. Idiot!
Requirements: a sandbox, toys, cardboard, armature wire, Sculpey, small camera. Fun factor: 5. Efficiency: 5.
Physical Blocking
This is an excellent technique. The idea is to block out the scene with your friends or actors and film them performing the action. This technique is used quite frequently by both Hollywood and indie filmmakers. For example, it was used on the Star Wars prequels for some sequences and is also a favorite of Freddie Wong. Highly recommended for people who have friends.
Requirements: friends or actors, space, props. Fun factor: 5. Efficiency: 5.
Virtual Production
This is the kind of previs that takes place on a mocap stage. Actors walk around in mocap suits and that data is instantly transferred into the 3D world. The director can follow the actors around with a monitor, which is treated as a virtual camera by the mocap system. What the director sees on the monitor is the 3D characters (which may not even look human) walking around in a virtual environment.
The director can even decouple blocking action from blocking camera moves. He can block the action first and then have the mocap played back later so he can walk around and block the cameras after the actors have gone home. Often when blocking the cameras this way, the relative motion of the camera will be scaled up so that a small movement of the preview monitor in the director’s hands can be translated to a 20 foot dolly move in the virtual world. Or the virtual camera can be offset so that the director can be sitting down in the back of the mocap stage and yet still be “following” the actors with a virtual camera. And of course, anything can be rapidly changed and rerendered, like props, costumes, or sets.
It’s basically the coolest freaking previs system you can think of, but it’s also the most expensive. Nowadays, entire studios are devoted to virtual production, like The Third Floor. And some directors, like James Cameron, Peter Jackson, and Stephen Spielberg have begun working this way almost exclusively. It’s pretty awesome if you can afford it!
I should also mention that if your film is mostly CG, then you can forgo previs altogether if you use this technique. They call it virtual “production” for a reason, because filmmakers who use this technique can literally MAKE the film in the blocking stage. (Avatar, Tin Tin, Real Steel).
Requirements: a lot of money. Fun factor: 5. Efficiency: 5.
Summary
So what have we learned? We learned that some previs techniques are better than others. For example, storyboards and 3D animatics (or anything that requires “keyframing”), is less efficient and less fun than “toy commercials” and physical blocking. We also learned it’s a myth that only filmmakers with millions of dollars can afford “good previs”. While virtual production is certainly the coolest technique around, I’m not sure how well it stands up in a cost-benefit analysis against “toy commercials” and physical blocking. A previs is not about having the coolest visuals–it’s about figuring out your shots in the quickest, cheapest, and funnest way possible.
Finally, I would recommend that you prototype your ideas EARLY. This advice is echoed over and over in all professions. This means you can start doing previs as an aid to writing the screenplay!
Please comment! What previs techniques do you use? Did I fail to list some technique? Thanks.
