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By profession I am a 3D Animator/ VFX Artist. I have a huge love for all aspects of the filmmaking craft. Because of this passion, I occasionally find myself in front of the camera. I’m usually there as a background actor, or “meat prop,” as I like to call it. Working as an extra is a fun way to stay involved with the big budget productions migrating to Michigan.
This summer I worked on one such movie. This particular film is a science-fiction set in the near future. Because of the genre and the set-up required for each shot, it promises to be loaded with visual effects.
Between camera set-ups, actors clad in motion capture suits rehearsed their moves.Crew members placed 3D tracking markers, while photographers snapped photos of the set and surrounding area. Other crew members took measurements of an apparently invisible structure. I distributed business cards.
While all this activity took place, I overheard fellow extras speculating on what the crew was up to. There were clearly many misconceptions. Most have never had the opportunity to learn the steps involved in creating a visual effects shot. Hopefully this brief overview, will shed some light on the dark art of visual effects for you.
First, let me throw some terminology at you. VFX is the industry abbreviation for Visual Effects. VFX often involves the integration of live-action footage and computergenerated imagery (CGI). That’s what we will focus on... The real world counterpart to VFX is Special Effects (SFX or FX). These are things that happen exclusively in front of the camera like scale models, prosthetic make-up and pyrotechnics. These real world effects are also called “practical effects”, and this is a topic for later.
To pull together a successful VFX shot there must be a clear understanding of the director’s vision. In my experience, when a group of creatives collaborate, there is a fine line between good synergy and having “too many cooks”.
Accurate storyboards make a good road map. Next, some questions need answers. Will the camera be moving or static? Will the CGI elements be static within theirenvironment (like a set extension)? or will they be moving (like a walking robot)? Each level of complexity requires more planning and more measurements and other data collected during filming.
To help visually illustrate the process, I’ve built a CGI video camera to place in a real-world environment. Our example is a still image. With some imagination, picture an animated CGI robot lumbering in front of a cheering crowd of spectators.
 The same basic concept, without motion.A CGI/real-world composite shot involves two workflows, the computer generated and the live-action (also called the “background plate”). [see illustration A]
The first step in the CGI part of the process is building a 3D model. “3D,” in this context, is a wire-frame computer model, not stereoscopic 3D. [see illustration B-2] This computer model represents the shape of our Canon video camera, but it lacks surface attributes. Before we apply them, each unique surface of the 3D model must be given a descriptive name like: “grey plastic” or “clear glass”. [see illustration C-2] After that we assign the various colors, textures, transparencies, and reflectivity that are found on the real world object.
When complete, the CGI object is recognizable but not very realistic. [see illustration D] It’s time to take advantage of the information gathered during production.
Remember those people taking photos on-set? They weren’t just capturing Michigan memories for their scrapbook. They were gathering images that serve multi-purposes. The images of the set’s surroundings are often in the form of a 360 degree panorama. They can be used to illuminate the CGI 3D elements. This is called “image based lighting” or (IBL). They can also be used as “reflections” in the shiny surfaces of our CGI model. Because the real-world photos were gathered on-set, they help to “marry“ the CGI to the background plate. And, reference images taken on-set are helpful to determine scale, light placement, and shadow direction.
Some other data gathered on-set include the camera settings like: focal length, shutter speed, and F-stop, as well as it’s placement. If shooting in a digital format, orover/under cranking a film camera, the frame rates need to be noted. All of this information is required to make the shot believable. Even the tiniest inconsistency can make the shot scream “FAKE”!
 In post-production, the 3D artists create the CG images on a transparent background. Often they are “rendered” as a special type of digital image. This file format keeps the various elements like base color, reflection, and transparency separate. Once reassembled and added to the live background plate, modulation of the separated elements is still possible. The computer artist who assembles it is called a “compositor”. Also, if tracking markers or stunt harness wires are visible in the shot, they will need to be removed from the background plate.
To help make the CGI look as though it was “filmed” along with the plate, artifacts like: lens flares, motion blur, and depth of field are introduced. Sometimes film grain is added. [illustration E] All of these attributes contribute to the success of the shot. In the end, it’s all about believability.
With the technologies available today, virtually (no pun intended) anything imaginable can be created. From an unassuming set extension or muzzle flash to the Battlestar Galactica, an evil creature made of smoke and flames, or even a boxing robot. But behind it all is a team of skilled creatives that bring the director’s vision to life.
B y profession I am a 3D Animator/ VFX Artist. I have a huge love for all aspects of the filmmaking craft. Because of this passion, I occasionally find myself in front of the camera. I’m usually there as a background actor, or “meat prop,” as I like to call it. Working as an extra is a fun way to stay involved with the big budget productions migrating to Michigan.
This summer I worked on one such movie. This particular film is a science-fiction set in the near future. Because of the genre and the set-up required for each shot, it promises to be loaded with visual effects.
Between camera set-ups, actors clad in motion capture suits rehearsed their moves. Crew members placed 3D tracking markers, while photographers snapped photos of the set and surrounding area. Other crew members took measurements of an apparently invisible structure. I distributed business cards.
While all this activity took place, I overheard fellow extras speculating on what the crew was up to. There were clearly many misconceptions. Most have never had the opportunity to learn the steps involved in creating a visual effects shot. Hopefully this brief overview, will shed some light on the dark art of visual effects for you.
First, let me throw some terminology at you. VFX is the industry abbreviation for Visual Effects. VFX often involves the integration of live-action footage and computer generated imagery (CGI). That’s what we will focus on... The real world counterpart to VFX is Special Effects (SFX or FX). These are things that happen exclusively in front of the camera like scale models, prosthetic make-up and pyrotechnics. These real world effects are also called “practical effects”, and this is a topic for later.
To pull together a successful VFX shot there must be a clear understanding of the director’s vision. In my experience, when a group of creatives collaborate, there is a fine line between good synergy and having “too many cooks”.
Accurate storyboards make a good road map. Next, some questions need answers. Will the camera be moving or static? Will the CGI elements be static within their environment (like a set extension)? or will they be moving (like a walking robot)? Each level of complexity requires more planning and more measurements and other data collected during filming.
To help visually illustrate the process, I’ve built a CGI video camera to place in a real-world environment. Our example is a still image. With some imagination, picture an animated CGI robot lumbering in front of a cheering crowd of spectators. The same basic concept, without motion.
A CGI/real-world composite shot involves two workflows, the computer generated and the live-action (also called the “background plate”). [see illustration A]
The first step in the CGI part of the process is building a 3D model. “3D,” in this context, is a wire-frame computer model, not stereoscopic 3D. [see illustration B-2] This computer model represents the shape of our Canon video camera, but it lacks surface attributes. Before we apply them, each unique surface of the 3D model must be given a descriptive name like: “grey plastic” or “clear glass”. [see illustration C-2] After that we assign the various colors, textures, transparencies, and reflectivity that are found on the real world object.
When complete, the CGI object is recognizable but not very realistic. [see illustration D] It’s time to take advantage of the information gathered during production.
Remember those people taking photos on-set? They weren’t just capturing Michigan memories for their scrapbook. They were gathering images that serve multi-purposes. The images of the set’s surroundings are often in the form of a 360 degree panorama. They can be used to illuminate the CGI 3D elements. This is called “image based lighting” or (IBL). They can also be used as “reflections” in the shiny surfaces of our CGI model. Because the real-world photos were gathered on-set, they help to “marry“ the CGI to the background plate. And, reference images taken on-set are helpful to determine scale, light placement, and shadow direction.
Some other data gathered on-set include the camera settings like: focal length, shutter speed, and F-stop, as well as it’s placement. If shooting in a digital format, or over/under cranking a film camera, the frame rates need to be noted. All of this information is required to make the shot believable. Even the tiniest inconsistency can make the shot scream “FAKE”!
In post-production, the 3D artists create the CG images on a transparent background. Often they are “rendered” as a special type of digital image. This file format keeps the various elements like base color, reflection, and transparency separate. Once reassembled and added to the live background plate, modulation of the separated elements is still possible. The computer artist who assembles it is called a “compositor”. Also, if tracking markers or stunt harness wires are visible in the shot, they will need to be removed from the background plate.
To help make the CGI look as though it was “filmed” along with the plate, artifacts like: lens flares, motion blur, and depth of field are introduced. Sometimes film grain is added. [illustration E] All of these attributes contribute to the success of the shot. In the end, it’s all about believability.
With the technologies available today, virtually (no pun intended) anything imaginable can be created. From an unassuming set extension or muzzle flash to the Battlestar Galactica, an evil creature made of smoke and flames, or even a boxing robot. But behind it all is a team of skilled creatives that bring the director’s vision to life
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Saturday, May 19, 2012
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