Tuesday, June 12, 2012

Visual Effects Tips 1

Here are a few tips and suggestions for visual effects artists. Some of these overlap my post on being a good visual effects artist. It takes more than just knowing how to use a visual effects software package to be good. The real key is to be able to accomplish great finished results within the constraints of the project.

I started writing up tips and found it getting rather long (and my time limited) so I've split it up a bit and will provide future postings.

Shot Objective
Be clear about what the objective of the shot is. The visual effects supervisor or director should be able to define their emphasis of the shot. Is there an action the main actor is making or a point that is being made? Then be sure not to obscure that and more than likely you might need to emphasis that. It very easy for everyone in the process to start focusing on the technical issues or on secondary issues and lose sight of what the shot is supposed to accomplish within context of the film.

Task objective
What is the specific task you’ve been asked to do on a shot? When is the first version due and when is the final due? Your visual effects producer has a number budgeted for your time. What are the parameters you’re working with and what are the elements you’re working with? What are the specs of what you’re creating? if you have any questions or aren’t clear be sure to ask.

Real versus style
Directors almost always ask for everything to be photo real. And yet they may make things very stylized by their choice of camera moves, camera speeds, looks, sets and other ingredients of the film. Very often a natural photo real look and a very stylized look are in direct conflict with each other.

It’s best if the visual effects team can be on the same page as the director and know his or her vision for the film and what the true balance is of real versus stylized looks. There’s also the choice of realism versus cinematic. As visual effects artists we tend to know what’s correct from a reality standpoint but the director may want it pushed to acheive a more interesting or exciting look.

The cinematographer may put eye lights on the actors to give them a highlight and emphasis their eyes. Those are the types of subtle cues and guides the team should be aware of and take advantage of.

Original digital visual effects were done in 8-bit log space and it was important for the cinematographer to provide color timed clips (color balanced film clips from the lab) for us to match to. Once these were locked it was important not to push them too far in any direction (darker, lighter, etc) due to the limited dynamics. These days shots are typically done in a neutral state but it is still ideal if the director and cinematographer can go into a DI (Digital Intermediate) suite and do some basic color timing of the key sequences. This indicates to the visual effects team which direction the movie is going in.

Don’t use this as an opportunity to hide sins of the shot but if in the final DI they will be turning everything sepia with a strong diffusion filter it would be good to know that early on. If you spent an extra day on each shot tweaking the color and exactly matching flesh colors, etc. for 1000 shots, that’s a lot of wasted time. The flip side is the director or the studio could change their minds in the DI session so that’s a discussion to be had.

If the project is to be stylized then the visual effects artists can likely help and take advantage of that or offer suggestions. Maybe the  animation has an extra flourish or the lighting is pushed more than it normally would be.

Learn to see
Spend time looking at your surroundings. The lighting, shadows and the look of things in the world. If you're an animator watch how people and animals move. Technical directors, lighters and compositors should be looking at how light interacts, how shadows work, etc.

Much of the time in visual effects is looking at a shot and trying to determine "what's wrong with this picture". Are there artifacts or is something making the shot look false? Do the visual effects match the live action portion of the scene? What are the standout problems?

You're going to be spending your time comparing to previous versions and to references. You should be able to do this without a supervisor having to point out everything.

Hopefully lighting references will have been shot on set by the visual effects supervisor. And these are good for technical starting points but additional references can prove to be very useful. The most important reference will likely be the live action element(s) that will be used. This will display many subtle issues the standard sphere or fisheye references do not.

If you have a creature or object try to shoot material references in the actual lighting. Feathers, fur, physical model, etc. can all be useful to shoot at the time of the other references.

Because here’s the thing, as much as you think you know exactly what something looks like you may be surprised what it actually looks like in that lighting setup with that composition. And without a good reference you and others may diverge so far from reality you may all be staring at the shot a few weeks later trying to figure out why it’s not working.

An example is a blue or greenscreen shot. Ideally you shoot the background first so you can match the lighting when shooting the foreground element. In that case make sure to shoot reference footage of a person standing in the area you expect to composite someone. This simple step is often ignored but is key to using as a reference for the cinematographer and for the compositor. It becomes clear looking at the real reference where all the lighting cues, lighting angles and contrast ratios are. The compositor looking at the reference can check how the edges work, how the light wrap works, how the final color and contrast is working for the actor in the composite. No discussions necessary, here’s the reference to match.

If an animator needs to animate a character pole vaulting then use a reference. Without that the animator, animation supervisor and director will all be having discussions about what it really should look like. What the grip is, how much flex should be in the pole, what the timing is, etc would all be endlessly discussed and debated.

Now the director may choose to make something more cinematic and to forego some or part of reality in order to make it fit into the style and storytelling task. But when starting with reality it always provides a control reference of where you’re starting from.

Paul Huston, a matte painter at ILM, had previously worked as a model builder. He frequently builds models and photographs them just to make sure he’s keeping to reality. They help provide the starting point to the painting.

Today with the internet and small digital still and video cameras there’s no real excuse for not having references. A quite internet search will likely provide plenty of images and videos of something that relates to what you’re working on. A camera, even in your phone, allows you to capture specific references, especially if it’s near by.

Accumulate references for the type of show and sequence it is. Hopefully production will have a pooled resource for all those working on the visual effects. And I would suggest continuing to gather personal references. Next time you’re walking or waiting somewhere take a look at the surroundings and see if there’s anything worth documenting. The way the light comes in the office window or the motion of tall grass may all be useful references.

Unless the project calls for it, avoid the weird or unreal. We’ve all seen bizarre clouds but if you put that in a typical matte painting it would standout and give a sense of falseness to the results, regardless of it’s basis in reality.


  1. I was searching for articles on VFX to become freelance vfx artist.
    Good work Sir, your articles are helpful.

  2. Good work sir, saw ur tweet abt vfx tips. Your articles are veryhelpful.
    thank you

  3. "If you make your own film, it really helps that you know what a cut means. A cut is very important to know because it helps structure things. The sounds, too. When we started on Jurassic Park, I spent a week or so with [sound designer] Gary Rydstrom because it was very important for Steven to have the voices for the characters. That was very helpful to inform our performances. Once you have the voices in your head, then you can work to the voices. That knowledge is essential."