10 VFX tips for saving time and money
1. Hire an on-set VFX supervisorAn experienced VFX artist on set will help you gather the right footage and avoid costly mistakes. The more VFX shots you're filming, the more important it is to have this person there. Even if you're just doing one shot, see if your VFX artist can stop by for a couple hours. You could film that shot first and get it out of the way. You don't need an Academy Award Winning VFX supervisor for your low-budget music video, but you also don't want a student who has never been on set. Your supervisor should have an overall understanding of VFX, experience with compositing and match-moving, and spent at least some time on set. Your friend the 2D animator who recently completed a 3D car modeling tutorial might do great work, but he may not know the first thing about the screen replacement shot you need. Every production will require a different set of VFX capabilities, but the ideal supervisor on-set is probably the person who will be completing the VFX in post. They'll be the most invested and able to offer suggestions that are within their capabilities. They might even surprise you with an idea you hadn’t considered. When a production can't afford to bring me on-set, I always advise them to shoot conservatively and not to try anything that's not in the storyboards. But when they do bring me on-set, I help the Director and DP solve problems, push creative boundaries, and avoid over-shooting.
2. Lock it downIf you can't afford a VFX supervisor (or if you're a first-time VFX supervisor), my number one piece of advice is to lock the camera for any VFX shots. This will eliminate 3D match-moving and a host of other challenges that go with it. Your hand-held monster chase through the woods might look awesome on camera, but it will be a nightmare in post if you haven't planned for it. Find a way to tell your story with lock-down shots if you can. One easy trick is to take a static shot and add a little hand-held shake in post.
3. Use storyboardsStoryboards are useful for any production, but especially one that requires VFX. Using a 3D previsualization or animatic is great if you can do it. At the very least, sketch out some stick figures or an overhead diagram on a piece of blank paper. Discuss this with the DP and the VFX artist days before the shoot. The communication will expose challenges you might face on set and allow you to make a checklist of the elements needed for each shot.
4. Don't use a green screen if you can help itI can't tell you how many times a client has handed me a pile of green screen footage and said, "okay, now work your magic!" Many times I've turned down projects because a director thought he was "saving money" when a team of ILM rock stars couldn't materialize his green screen dreams. If you're shooting on green screen, it should be for a good reason. Is it because you happen to have access to a green screen stage? Bad reason. Think you'll save money on locations? What about the time and money you'll spend creating a digital environment? There are many good reasons to shoot on a green screen stage -- impossible locations, period pieces, and insert shots to name a few, but you should have the resources and planning to back it up. It might seem obvious, but if you want your actors or your products on a white background, just shoot them on a white background. I hate when clients hand me green screen footage and then ask for the “Apple commercial” treatment.
5. Use an insert green screen and a clean plateThe main instance where I do recommend a green screen is when it saves time on rotoscoping. Is there a CG spaceship landing behind your main character? Drop a green insert screen behind your subject! It will minimize rotoscoping, and, if you know how to pull a proper green key, it will be a better looking result. Of course, you'll also need to shoot a clean plate -- also known as a background plate. Clean plates are shot with no action or actors in the frame. They’re usually filmed last, although sometimes you may want to film them first if you're blowing something up or making a giant mess. Clean plates are also useful when you’re not using a green screen. I've spent countless hours rebuilding and repainting a shot because the production team didn't shoot a clean plate. It only takes a minute to clear the frame and roll the camera. If you're not sure if you should shoot a clean plate, that probably means you should shoot a clean plate.
6. Shoot stills for referenceIf your production requires complex VFX photography like HDRs, 360 panos or chrome ball shots, you’ll want to hire someone with that specific experience. But anyone with an iPhone can easily grab a few still photos of the walls and floor of the scene. For example, if you wanted to remove a dolly track from the floor of a shot, an overhead still photo of the floor (without the dolly track) would be very useful. If you’re doing scene extensions or matte paintings, it’s great to have photos of anything that might be referenced or reused in post--grass, dirt, rocks, concrete, sky, etc. Again, if you're unsure what still photos you need, ask your VFX artist.
7. Use tracking markers when you need themThe proper use of tracking markers could make up an entire class taught by an experienced VFX supervisor, so I won’t be able to cover it fully here. However, here are three quick tips:
- If it isn’t moving, you don’t need tracking markers
- If it is moving, you probably need tracking markers, unless there are already naturally occurring tracking points (i.e. the corners of a screen or lines on the ground)
- Take a photo before placing the tracking markers and use it to remove them later