Title: The film guide to visual effects : the art and techniques of VFX for directors, producers, editors and cinematographers / Eran Dinur. This book fills the gap by providing a comprehensive approach to visual effects from a filmmaker's perspective.
VFX FUNDAMENTALS
Core Concepts
The credibility of visual effects depends not only on the quality of animation, detail and integration. First, to clarify, animation is obviously an integral part of the visual effects and game production processes.
VFX as a Filmmaking Tool
The screen material is "baked" into the footage - the only way to change it later is by removing and replacing it in VFX. But filmmakers often choose to rely on visual effects for some or even all of the action elements.
From 2D to 3D: The Quest for the Lost Dimension
D: The Hybrid Solution
Note that the cards are not yet arranged in the correct order: the rubble element must be right in front of the plane and the utility pole must be placed in the back. But if you use a projector to project an image onto the screen, the image will not change at all when you move the screen (basically the screen moves “through” the image).
Separation: Roto, Green Screens, and the Challenges of Extraction
It's always a good idea to record at least some parts of the shot. Perhaps it's the fact that most of the VFX work takes place during the post-production period. Merging the roles of VFX supervisor and producer into one role is usually not a good solution.
How much wallpaper needs to be replaced and how much will be kept. Original shot and final compensation of one of the shots in the Nerve crane scene. It's easier to set up action and crowd reaction when the extras are closer to the camera.
One of the VFX tiles is used to fill the center booths of the top floor. As the cut progresses and the full scope of the VFX work is revealed, the budget must be revised accordingly. Setting a tight schedule is in the best interest of the filmmakers as well as the VFX team—both parties want to get things done on time.
Never hesitate to ask for clarification - it's the VFX team's responsibility to clearly indicate where they are in the progress of the shot and what they still need to address.
THE INSIDE LOOK
The VFX Workflow: An In-depth Look at the Various Crafts of Visual Effects
Note the rather rough appearance of the elements and the use of a piece of old photo. The decision to hire production concept artists (or use VFX company's in-house concept artists) largely depends on the type of VFX shots in the film and the nature of the CG elements. By tracking the movement of a large number of points in the footage, the matchmove software analyzes the parallax to "solve" the movement of the camera.
On the other hand, displacement generates a much more realistic appearance as it actually changes the shape of the model. The integration of CG elements into the footage depends a lot on the work of the lighting artist (often called the Lighting Technical Director or Lighting TD). Notice how the sky, light and mood of the original image are preserved in the matte painting.
Workflow Case Studies
Background Cleanup
Like most fix-it pictures, this was never planned as a visual effects shot, and subsequently there was no green screen to aid in the separation. The actors' body and the objects around them were fairly easy to rotate, but both actors' hair was not, especially since the truck was moving right "through" it. All told, with two artists working together, this shot took four days to complete—putting it in the mid-range of fix-it shots in terms of time and cost.
The Homestead Strike
A composer also joined in, updating the composition as roto and matte painting progressed. Camera tracking took one day and environmental imaging took about five days. This kind of matte painting also requires feedback from the filmmakers—it's an important visual element in the shot—so we sent a single style frame for review and feedback before the roto and compensation were even finalized.
It took about a week and a half of compositing to get all the tiles out, lay them out to create the crowd, work on the integration and fix the little details. With four artists and some of the work overlapping, the shoot took just under two weeks to complete.
Piranha Attack
Overall, the work took several months to complete, from the collection of reference material through the preliminary animation tests to the final comp. When dealing with CG elements, we can divide the work into two categories: asset work and shot-specific work. Therefore, the work spent creating the asset does not need to be repeated for each shot.
Shooting-specific work includes tracking, animation, simulation, lighting, and compositing—tasks that depend on factors that vary from shot to shot. On the other hand, specific shot work must be done individually for each shot, even when the same asset is reused. Camera movement and lighting vary between shots, and the animation is definitely unique to the shot.
Tsunami Mayhem
Filmmakers and the VFX team must have a clear idea of the scope of the visual effects and work within those guidelines and constraints on set. But if the frame is mostly green screen, it's much better to shoot it clean, as large chunks of smoke will disappear with the green screen and the VFX team will have to recreate them anyway. Much of the VFX work on stunt scenes involves removing harnesses, wires, platforms, high falling air.
For the dozens (or hundreds) of VFX artists, this is the real Everest climb, where most of the VFX work is done. It is important to remember that the daily video clips are compressed, low quality versions of the raw footage. At this point, the VFX team will send the high-resolution, full-quality version of the shot directly to the lab or DI facility.
It's a total waste of money to have the VFX team work on a shot that will later be cut from the movie or replaced with another shot (which, in terms of VFX work, is practically a new shot is). It's also a good idea to send an additional edit ref of the entire sequence (even if that sequence has a lot of non-VFX shots).
VFX IN PRODUCTION
Pre-production
There's really no need to be too specific or figure out detailed solutions at this point, as that will happen later with the help of the VFX supervisor and VFX producer. Things will clear up once the VFX supervisor and producer join in and the planning process begins. These two key roles can be roughly equated to the director and producer: the VFX supervisor is responsible for the creative, artistic and technical side of the visual effects, while the VFX producer takes care.
Likewise, when working with the VFX artists, he/she must maintain a broader view of the film as a whole, while also looking at the specific technical and artistic details. Traditionally, the VFX supervisor and producer are hired as part of the film's production team, and are not affiliated with the VFX facilities that will ultimately do the VFX work. In such cases, it may be more economical to use the VFX company's in-house supervisor and producer.
Dedicated Production VFX Supervisor and Producer
But for reasons I'll describe below, this arrangement is sometimes overkill for low-budget films with a limited scope of VFX work.
Company In-house VFX Supervisor and Producer
To better evaluate a bid, you need to understand the underlying cost factors from the VFX company's perspective. However, from a director's point of view, you have to understand that real film prices (instead of losing minimums) are actually beneficial not only to the VFX company, but also to your film. Storyboards are also very useful for the bidding and budgeting process as they provide the VFX team with a clear visual reference to the director's ideas, so it pays to hire a good story artist fairly early in pre-production.
Meetings usually include the supervisor and producer on the VFX side, and the director, line producer, and first AD on the production side. On the director's side, it's important to clearly lay out the creative vision, while also being attentive to issues raised by the VFX team and other departments. All too often, HODs on tech scouts discover an issue that is impossible (or too expensive) to handle practically, and filmmakers turn to the VFX supervisor and producer to check if a VFX solution is feasible instead.
On Set
But it's important to remember that those VFX elements ARE a part of the shot, sometimes a necessary part. One of the most common assumptions is that tracking markers need to be a different color than the screen to "stand out". And the fact that they are still a shade of green makes it very easy to pull off with the rest of the green screen.
If there are no static objects in front of the screen that can be used for tracking, it is recommended to add some markers between the camera and the screen at different distances. One parameter that can help the decision in such cases is the size and prominence of the green screen in the shot. Just like with green screens, tracking markers are needed when the screen covers most of the frame.
Post-production
When the VFX team works on the raw footage, they keep the color intact (unless a color change is part of the VFX work, for example a day-for-night shot). It's great for general reference (e.g. when sending sequences for bidding), but I wouldn't recommend using it for editing references (see the VFX and editorial sections that follow), especially if the color needs to be adjusted by VFX Team . Feedback from the filmmakers should be documented, organized and returned to the VFX team.
This may seem simple enough, but it is often a source of friction between the production and VFX team. It is equally important for the VFX team to update the production and clearly mark any delays. But it's still up to the VFX team to figure out what's bothering the filmmaker.
The Future
