So this is where my lectures from CS4340 Digital Special Effects is going to come in handy. :)
What are "Special Effects"? What are "Visual Effects"? What are the differences?
Special EffectsSpecial effects and visual effects may create an illusion/effect to make the scene more convincing to audiences, but the workings behind both are different.
Special effects are effects that are created within the set, in the context of the actual live-action shot. According to Wikipedia, special effects have traditionally been categorized into two separate effects: on-set
mechanical effects and in-camera
optical effect.
On-set mechanical effectsMechanical effects are created using mechanized props/scenery/scale models/pyrotechnic and atmospheric effects (creation of rain for example.. this reminds me of a time when I was touring South Korea with my family and saw a group people shooting a video with fake rain. They kinda like a big shower thingy and simulated rain!).
Examples (of the infinitely possible) include having doors that were 'engineered' to break during a fight scene, controlling a robot (off camera) so that the robot appears to be moving on its own etc.
Of the many breakthroughs in visual effects, the most noteworthy ones to me are Star Wars and Lord Of The Rings. For Star Wars, it was simply just out of the world (literally) at that specific era. And for Lord Of The Rings, the breakthrough came about most prominently in their use of perspectives to create the difference in sizes of the wizards and hobbits (will show an elaborate further).
Here are some videos to illustrate mechanical effects:
In this video, ILM (Lucasfilm's Industral Light & Magic) talks about how they created the character Jabba in the 1980s using a life-sized modela and people were controlling its expression. Obviously, such techniques will not be used in modern days anymore as we can easily generate CG models using computer software like Maya.
(P.S. A great resource to find out more about the special effects in Star Wars is: "From Star Wars to Jedi: The Making of a Saga". This video posted here is extracted from this resource)
This is about how the brilliant minds in LOTR achieved forced perspective.. and not just any simple forced perspective of how tourists do it by having their subjects stand and pose at a distance so that they like they're 'punching' the Eiffel Tower.. BUT FORCED PERSPECTIVE WHILE THE CAMERA IS MOVING! This is just incredible. Basically, how they achieve it is by having the characters at different positions and sliding them along while the camera moves so as to keep the forced perspective consistent!
Ok, this is just bizarre. We watched this video during a CS4340 class and we figured that they did this by having a large set that could actually rotate and have a camera fixed in the room (so it rotates together with the room). Pretty cool. We guessed that it's highly probable we're right because the actors always hesitate a while at the corners of the room which kind of suggests that they were waiting for the room to rotate till it's more stable for them to move on to the wall or ceiling.
And at about 3.02, it's quite obvious that the table is shaken manually (either by hand or by machines).
This is a very informative video of how to make a person look old. It's really cool!
In-camera optical effectsIn Wikipedia, optical effects (also called photographic effects), are techniques in which images or film frames are created photographically, either "in-camera" using multiple exposure, mattes, or the Schüfftan process, or in post-production processes using an optical printer. An optical effect might be used to place actors or sets against a different background.
Here is an episode in Movie Magic (embedding is disabled):
http://www.youtube.com/watch?v=GsSz5MZRNt0One of the scene in this episode, it explains how compositing is achieved in a scene in Star Wars - whereby the characters are filmed with a blue/green screen and change the environment using an optical printer. This episode is mainly about the
optical printer.
The famous bullet time technique pioneered in Matrix is achieved by using a row of cameras taking still shots and then fitting them together into the video so that they appear smooth. This shot, obviously, also has visual effects in them, which I will talk about next.
Back to Star Wars, here is a link that summarizes how the lightsaber shots are achieved:
http://www.scientificpsychic.com/fun/Basically, the lightsabers are rotoscoped in (i.e. painting over the film frame-by-frame, which can be done digitally now).
Visual EffectsVisual effects, or digital special effects (here's where it can get confusing), are effects that are generated by a computer, e.g. the robots in Transformers.
Visual effects (commonly shortened to Visual F/X or VFX) are the various processes by which imagery is created and/or manipulated outside the context of a live action shoot. Visual effects involve the integration of live-action footage and generated imagery to create environments which look realistic, but would be dangerous, costly, or simply impossible to capture on film. Visual effects using computer generated imagery (CGI) have become increasingly common in big-budget films, and have also recently become accessible to the amateur filmmaker with the introduction of affordable animation and compositing software.
- Wikipedia
Digital compositing, a term widely used in VFX, means digitally manipulating and integrating at least 2 images to produce a new image.
Ok, enough talk, more show! There is an abundant pool of examples which we can draw from, but here are just some.
How can we not mention the technology used in Avatar when we talk about VFX? It's the new frontier! James Cameron uses the technology of performance capturing with motion capture (mo-cap for short).
This is a breakdown of the VFX in Pirates of the Caribbean. There are also elements of using blue/green screen and then chroma-keying the screen out (i.e. remove the screen).
This is a pretty cool breakdown of a HP commercial. Basically, the effect is achieved by using a green screen to capture the person's head. Almost everything else, i.e. his clothes and the office environment are generated by CGI.
This is a breakdown shot of what somebody did (not in the movies).
This is a cool video of the more modern Star Wars.
What are the benefits and disadvantages?The most obvious benefit is that it helps producers/directors achieve something in the film that they will not be able to shoot live in normal circumstances. However, the difficulty in this is the time and effort (plus careful observation) on making the effect look realistic and thus believable. Believability is the most important component in VFX these days, coz nobody's ever going to pay to watch a movie with lousy effects..they're just not going to be satisfied.
These special and visual effects help filmmakers cut costs in some sense because for example, they cannot possibly build an entire planet! If they are going to need tens of thousands of people to shoot a war scene, digital special effects can greatly cut costs too.
The disadvantage is that, as mentioned before, it takes a lot of skill for VFX to look good and these talent is quite expensive. If any thing in the effects breaks realism, it will not look good at all and will ruin the entire effect.
