If you've watched movies in the past 10 years, you've probably at some point complained about horrible CG, because you movie viewers are ungrateful little jackanapes.
Every time CG goes well and blends seamlessly into the movie (I bet you didn't know it was used in Brokeback Mountain), people rave about the amazing acting performances and the wonderful storyline and maybe the great soundtrack, and every time it goes wrong, everyone talks about how CG is terrible and is ruining movies.
I'm not joking, watch the video.
But that's OK, whatever, it's a job, nobody says thank you to accountants and insurance underwriters either. I can't brag to anyone about having worked on The Mummy: Tomb of the Dragon Emperor, but it put food on the table. But you know, as long as we're criticizing crappy CG, I thought maybe you'd like to know more about the details of how each terrible disaster unfolds behind the scenes, and more importantly, who to point fingers at.
Here's some of the more common complaints:
7Skin Looks Like Plastic
One of the creepier CG sins is to make skin look like plastic. This was only one of many many things wrong with the Scorpion King character above, who actually only appeared in scorpion king form in The Mummy Returns and not in any of the three movies actually named The Scorpion King, because Hollywood likes to confuse us. (Yes, it had two direct-to-DVD sequels. No, nobody watched them.)
When moviegoers say skin "looks like plastic," it can mean a few things. Sometimes they mean faces are rigid and motionless, as if they were made of hard plastic like some kind of creepy doll, which is usually a rigging problem, which I'll talk about later. Sometimes they mean the skin has the texture of plastic, like their face has been shellacked.
Sure, this was 11 years ago, but let us note that the Rock lent his face to this hilariously shameful visual effect the same year that the first Lord of the Rings movie came out.
They hadn't reached their full potential yet (Gollum comes along in the later movies), but clearly, plastic-Rock-head-pasted-on-monster was not "the best you could expect from CG at the time" by any means.
One of the (numerous) things they would do to make Gollum look much, much less like a bad video game character than the Scorpion King was to make his skin not look like frickin plastic. The person responsible for this is the person who writes the shaders. When a character is modeled, or "sculpted" in 3-D, at first it has no color. When modelers show their work for approval, it usually looks like a statue made of dull gray clay.
In fact, freelancers will sell models at this stage. This one is going for $275 on TurboSquid:
A shader writer is a person who writes a program that tells the computer how to "paint" the model -- not just what colors, but how shiny or dull, how bumpy or smooth, how transparent or reflective it is, depending on a bunch of factors, like whether it's facing you or you're looking at it at an angle. Lots of science.
Skin is made of a lot of layers, so it's really complex, and they were really far from figuring it out back when Toy Story was made, for example, which partially drove the decision to make the movie about a lot of plastic toys and not about humans with skin.
The big breakthrough was a thing called subsurface scattering. Read that linked tutorial if you want to find out more about it, but basically, it accounts for light bouncing around through all the layers of the skin so your character stops looking like the picture on the left and starts looking like the picture on the right:
When they finally figured this out, they used it on Gollum, The Incredibles and everything else. Any skin that looks like plastic today doesn't have the "we don't have the technology" excuse anymore. Some asshole is dropping the ball or skimping on the budget.
6Character/Vehicle Looks Retarded
In the case of Anaconda 3, I mean this literally. The snake looks like a snake that was born, through no fault of its own, with significantly impaired cognitive function compared to other snakes.
Now, Anaconda 3 clearly had a budget of about five dollars, and for most people, that's reason enough why the CG would suck. But that makes it sound like all the problems are technology problems, like they couldn't afford computers good enough to magically make a snake that is shaped like a snake, for example. Technology and money are needed for a lot of things, like complex shading and rendering of skin and water and that kind of thing, but it doesn't take money to make a snake shaped like a snake, it just takes a person who knows what a snake looks like.
Not like this.
There's a couple of people who might have dropped the ball. One is the art design team, who usually draw up 2-D drawings of the characters they want to make for the film. These drawings get handed off to modelers, who then "sculpt" the characters in 3-D on the computer. Their finished product is the gray-clay-looking models pictured in the previous entry.
The art team might have drawn a shitty snake, or the modeler may have bungled the attempt to create a 3-D model out of it or, considering the movie we're talking about, both of them were probably the same person, the director's nephew who just got out of animation school or something along those lines.
Sometimes the blame goes a bit farther up, as there is usually a chain of command that has to approve the art team's designs, as well as the resulting models. Here's a couple of widely reviled vehicle designs courtesy of Star Wars Episode I and Star Wars Episode III:
There's nothing wrong with the execution by the modeling team -- they are very well done and realistic-looking models of stupid vehicles. The drawings were shown to the art director and the VFX supervisor, and probably went straight to the director/producer -- I don't have time to look up who that was -- and he approved it.
Ang Lee's The Hulk is going to come up a lot, because it was a VFX abomination, but one of the biggest complaints was about the unrealistically bright green skin on the title character (Jennifer Connelly). People heap a lot of scorn on the VFX team from ILM (Lucasfilms' award-winning Industrial Light & Magic) for this, but what they don't know is that their original tests had more toned-down, realistic versions of the green Hulk skin, but when they showed them to the director -- again, I don't have time to look up who directed Ang Lee's The Hulk, but you can probably find it on IMDb -- he nixed it and said, "No, it needs to be more green!"
The director's word is law, so they have to do what he says, and now everyone thinks ILM's VFX team doesn't know what skin looks like. Now people think Rhythm & Hues' team (on 2008's The Incredible Hulk) is just smarter than them.
ILM's 2003 Hulk is on the left, obviously, and R&H's on the right.
The lesson is that if you have a director or art department with no taste, there is not a thing the dozens or hundreds of CG artists can do about it, except follow orders and make the awful things.