Writing (and Directing) Visual Effects Shots

Besides being a visual effects artist and motion designer at Evil Planet Studios and a graphic designer for ReDCroW Design, I’ve had my healthy share of writing and directing. Ever since I remember I always liked story-telling and that was one of the driving factors that led to my incursion into writing and directing my own shorts. But every once in awhile I get carried away and end up coming up with some impossible-to-produce piece of work that slowly dies on the drawing board and leaves me wondering: “What the hell just happened?”.

See, the problem about writing a visual effects shot is that it looks awesome in your head, it looks great on paper, too and it would certainly look awesome on screen but to make it happen you would need a budget equivalent to the GDP of a small country. But why? The answer may baffle some: It all boils down to time. And time=money. Whether it’s your time, an un-paid intern’s time or the time of the artist you hired to do the visual effects.

I had to learn this the hard way, some of my scripts ended up as botched productions or simply un-filmable projects. Now I am sharing my experience with you, so you can take into account the many variables and requirements that go into writing visual-effects-loaded scenes.

1. I don’t like that background, please change it. Sometimes the script calls for a set extension or your subject or subjects on a completely different background than they were filmed on. Commonly known as matte painting. A matte painting is a movie set alteration in post-production that allows the film maker to create the illusion of a surrounding that is either too expensive to visit or impossible to build.

The problem with these shots is that you need to separate the subject(s) from the background. This is achieved in one of two ways; Either filming the subject on a green screen or rotoscoping it.

This entails that your film making crew MUST have a green screen and lights lying around somewhere, which makes the background alterations easier to do or that your VFX artist will spend countless hours painstakingly cutting your subject(s) or background elements out of the shot. As I found out the hard way, this will slow down and stall your production for days or even months.
Now, you must be saying: “But Armand, there’s software that does the rotoscoping for you nowadays”. And yes, dear reader, there is. However when you finally sit down and try to actually use it, you’ll realize that sometimes your software will not pick up the subtle differences between the background and the elements you are trying to rotoscope and you’ll end up actually spending more time than you actually planned adjusting settings or even having to do the rotoscoping by hand anyway. Why take the risk? Just use green screen.

2. I don’t like that guy, delete him! As a motion designer or VFX artist, I often get customers who want me to “delete” something from a shot or change the movement or direction of an object/character and when I tell them the price tag that goes along with such a feat, they recoil, saying “What’s the matter? Can’t you just delete it?”. I always found that question laughable because when you select a bunch of pixels on a shot and simply delete them, what you get is a hole.
The problem with bidimensional footage is that it is, well… Bidimensional. You only have one layer, if you delete pixels off that layer, all you gonna get is no pixels and you have to draw them back in. So for example, if you want to get rid of a person in your shot that is not suppossed to be there, you actually have to draw the background on top of where that person used to be and this is achieved in a variety of ways, usually using samples from surrounding areas in the same shot, if there’s any. And if there aren’t areas for sampling, may God help you and your VFX team, because you’ll have to re-create that background from scratch! The best way of “deleting” things off your shot is not having them there in the first place and the best way of making them move in post-production is shooting them on a green screen and having a clean shot of the background (preferably with the camera locked in position on a tripod), then combining both in post-production.

3. ENHANCE! One of the biggest pet peeves of a digital graphic artist is to work with a tiny little graphic that has to be blown up 10 times its original size to fit larger footage.

It’s just not going to happen, no matter how hard you wish for it. Bitmaps are comprised of little squares, each square is called a “pixel”. Now, if you have an image of say… 200 square pixels and blow it up to 2000 square pixels, the only thing that will happen is that you are going to end up with a mosaic. Sadly, it just doesn’t work like in those CSI shows, where they take crappy CCTV footage and magnify it 200 times to find the reflection of the killer on the victim’s glasses. What the artist does in real life is basically recreate the original and sometimes there isn’t even enough information in the graphic to do that. With that in mind, while writing a shot, be aware of the size of your footage and the assets you are planning to add to the shot, it’s not like you can go back to film it again.

4. We’ll just CGI it later. For the low budget film maker, CGI should be a last resort, not an all-purpose-fix for everything. Contrary to popular belief, CGI will not make your film more awesome. In fact, more often than not, it may make it laughable if you don’t invest a ton of time and money into it.

CGI is a tool. It’s perfect if you want to add bullet holes that will appear for a short period of time on camera, blood squibs, pyrotechnics, muzzle flares even (although ideally, you want to get these done on camera too) but when you try to go overboard and add creatures, vehicles or collapsing buildings, you better be prepared to get a good artist. Think about it this way: Even big Hollywood productions pull incredibly bad CGI effects, what makes you think that you won’t, without a massive team of artists working for you?

5. Rain, fog and atmosphere. Although some of these will look awesome without much work, more often than not, adding them in post production will just look lazy and unprofessional. The world is three-dimensional and so are your effects. Atmospheric effects surround your subject(s) and the topography in your shot. This means that you will probably have to either green screen or rotoscope them out to make them convincing. They build up over distance and perspective plays a vital role here. The farther away your movie set goes, the denser will be your effect. Fog will appear whiter and thicker in the background than it does in the foreground, rain drops will be more closely packed, etc. Adding these in post-production is just not as easy as it sounds. And certainly can’t just be achieved convincingly by overlaying the asset of your choice on top of your footage. It can be done if you are looking for a quick fix, a quick scene no one will be paying attention to, but a convincing scene will take a lot more than just overlaying your atmospheric graphic on top of your footage with some cool blending mode.
And that is just the beginning, your scene also has illumination. Illumination that lights up the raindrops or creates volumetric light effects in your fog, or scatters in your smoke, all these effects have to be taken into account when doing an atmospheric effect.

6. Motion Blur. Movement is your enemy when you want to add VFX to a shot on a budget. Depending on your aperture, shutter speed and ISO you will get motion blur, which will make tracking objects in the shot very difficult. But of course, not all is lost; Your director of photography can shoot these at a high shutter speed and minimize the motion blur. It actually makes it even more realistic when you match the original footage’s motion blur in your CGI but you still have to track the camera and the objects in the shot, which can be time-consuming. Tracking points will need to be added to the objects and sometimes to the set too and in some cases the motion blur makes them almost invisible.
On the other hand, let’s pretend your footage was filmed at a high shutter speed and you have a nice shot without motion blur. The human eye will immediately tell that there’s something wrong with the shot so you have to add the motion blur back in, just so it doesn’t look weird. But here’s the problem with that: Most softwares and plugins that do this will require you to invest countless hours rotoscoping things in the shot so the software can tell what’s what. You see, the way a computer does it, is they track pixel movement and then they interpolate the missing in-between frame data and then they render a bunch of semi-transparent frames in sequence to simulate the motion blur. Easy enough, right? Well, now imagine you have frames where pixels move so fast that they only appear once per frame, never to return again (commonly seen with objects in the foreground that quickly move past the camera during a pan), the program doesn’t know what to do with them and just renders a weird artifact with jagged edges instead. So a work-around in advanced softwares is that you can rotoscope the pixels that generate the artifacts and tell the software that this is in fact, an object that only appears once in front of the camera.

This doesn’t necessarily mean that shots with motion blur are completely forbiden, but the more of it there is, the more difficult it’ll be to track the camera movements and the objects in it.
Remember, a locked camera shot is boring, but will save you days in post-production. Use VFX on moving camera shots only if it’s absolutely necessary or the story calls for it.

7. Lights, camera, ACTION! Light plays an essential role in all of this.Depending on the camera you choose, your footage may not have enough information to work with. Either too much or too little, once you reach one of these two extremes your footage will have “dead areas”.

You can’t brighten or darken it up in post-production, because the brighter or darker it is, the less colors you have to work with. There is nothing whiter than white nor blacker than black.This is just as bad as grainy or blurry footage and will be a pain to work with so be aware of your light situation while writing a scene that happens at night or with the sun facing the camera. This way you will be able to plan better your shots and bring lens filters or lights.

8. Creature Effects and digital makeup. Let’s face it, sometimes you want some over-the-top special effects and makeup, animatronics and creature suits just won’t cut it; they can be either overwhelmingly expensive or unconvincing, sometimes it’s better to add them in post-production than as practical effects. But then again, the time you spend doing the CGI is just not worth it because it still looks cheap.

Now you are trapped. Either way it’ll look bad. So before creating that monster you want, ask youself: Who is more skilled, Your VFX artist or your special effects artist? If the answer is neither, you might as well just use a shadow or make the action happen off camera.

9. But…How? At this point you might be asking yourselves, all that is fine, but I don’t know any visual effects artists, let alone good VFX artists.
Well, Google is your friend. And so is YouTube. Search for tutorials, Google for VFX artists, look for film making boards, nowadays there are VFX artists just about everywhere. VideoCopilot.net is a really good resource for beginners and intermediate users alike, I highly recommend it. Also, Indy Mogul and Film Riot on YouTube, both offer tutorials and how to’s on how to achieve VFX shots.
Or, you can also check my portfolio and see what I can do for you.

This article’s objective is not to scare you into not using VFX and avoid all these shots altogether, but be aware of your own budgetary and time limitations while writing the scenes. Use the visual FX sparingly and be okay with your shot not necessarily looking like a big Hollywood blockbuster. Sometimes it takes a bit of suspension of disbelief to watch a film.

As stated above, visual FX take time and money to achieve, but just how much of them should you put into your production? Think of visual effects as candy; Eyecandy. You don’t want to spoil your viewers with too much of it or it’ll give them an indigestion. Of course there are shots that require them to work, like adding content to otherwise un-viewable or blank computer and TV screens in your shot or CGIing-out things that were not supposed to be in it such as cables or production equipment but aside from that, adding too many not only is going to be expensive or time-consuming but will also make it look inferior.

In this day and age visual FX are easier to produce than ever but that doesn’t mean you will have easy access to professionals who deserve to be working for Industrial Light and Magic or Digital Domain. More often than not, your VFX artist will have his or her own limitations and cramming your film with visual effects that are not completely seamless, will only make it look unprofessional.