The Grand Finale: Adventures in the World of Chroma Keying

The Final Project    

For my final project of the year, I was tasked to explore the process of chroma keying, which is the technique of removing a background from footage to place said footage over another background. This is typically done with the use of a green screen, which I did use. I worked with my friend Mike Webster (his blog has been linked) to film some very basic footage in front of a green screen, and then used the Keylight plugin in After Effects to remove the background and place it over a background image. After getting the footage, we both edited it in our own separate way. Given the closeness to the end of the year, there was not much time to polish the final product, although I did create a very rough version that demonstrates the process to some degree.

The Project and Pre-Production

My own project involved me walking up to greet a friend, walking away, and tripping/exploding in a blaze of glory. It was laid over a background of a calm looking field, mostly because said background was free and from a website that was not full of malware. I began the process by creating a very simple storyboard, attached below, to plan out the simple action of the scene. Afterward, I went and downloaded a few free green screen images to practice the chroma keying process (you can see one of my attempts, the Chernobyl Cat, below). This practice was nice, but not entirely representative of real chroma keying, given how the background of the subject (the cat) was one perfectly solid block of color. This luxury was not afforded to me in the actual project, due to inconsistencies in the lighting of the green screen as well as the camera being somewhat out of focus. At any rate, the next step was to film the footage that would be overlaid on the background.

The Storyboard. Not much, but it's something.

A smaller version of the background image we used.

It's a cat in Chernobyl. I don't know where I was going with this.

Production and Post-Production

After acquiring a camera, Mike and I filmed the scene (not a tremendous task, given its simplicity), and imported the raw footage into After Effects. Using a plugin called Keylight, I took a sample of the green screen's coloration and modified the Clip White, Clip Black, and Screen Gain parameters until the green screen was completely transparent while Mike and I were completely opaque, with a somewhat transparent outline surrounding us. I also modified the Screen Shrink/Grow and Screen Softness parameters to soften the edge between the foreground and background. Finally, I added some assets from the Action Essentials footage pack to create the explosion, and used a sound clip from SoundBible.com to put the finishing touch on. You can see the raw and final footage below. Had I had more time, I would have also added color and lighting correction to the foreground to make it match the background image, and also would have refined the edge of the foreground footage to make the blend between the foreground and background even smoother. Most of the issues came from the somewhat shoddy camera work we did, as the camera was not focused well, nor was the green screen lit particularly well. There was only so much I could have done in post-production to fix said issues, although I did what I could to make the final result as presentable as possible. I also would have better refined the Action Essentials assets to feather out the edges of the explosion and smoke, but again, time constraints prevented me from doing so.

The Concepts Involved and Lessons Learned

Through this exercise, I learned the basics of the chroma keying process, including setting up a green screen, taking the foreground footage, and using Keylight to render the green screen transparent. In addition, I learned more about the process of planning live-action shooting (however simplistic said shooting may have been) and how to deal with complications in the shooting process (read: it took us about a week to get access to the studio and a camera). I also got a slight review in overlaying assets for special effects, although it was not the main focus. This was a nice refresher in special effects editing, which I haven't done much of since the end of my sophomore year. Knowledge of chroma keying is instrumental for a majority of special effects in movies, so knowing the process, even if I likely won't end up using it much myself, makes it much easier to understand and appreciate the work and thought processes involved. Although the end result wasn't that great, I believe that, with more time for refinement through color correction and edge transparency as well better raw footage, using the same method would have yielded a presentable result.

A Reflection of this Semester

My main projects this semester were this, and the Goodnight Moon animation detailed in my last post. Both involved a break from 3D work in Maya and had a heavy focus on After Effects use. Both were not ridiculously difficult in terms of technique, so I didn't have too much difficulty with any of them. Maintaining focus on Goodnight Moon was at times difficult, due to the large amounts of work involved in animating almost every segment of the book in Photoshop as well as syncing it with the voiceover and sound effects, but I did manage to finish it without any major complaints. You can see the final version below.

This project, although quick, was very information-dense. However, this information (at least the pieces that I learned) was fairly easy to take in and apply to my work. Like I said, my main qualm with this project wasn't the work with the actual post-production editing, it was with the initial shooting of the footage. I don't have much of a background in video, so I just went with what Mike said and hoped for the best. Considering the fact that I only learned about this skill a week ago and only had two or three days to put this together, I'm not too upset about it.

Unrelated to the two major projects this semester, I also received an honor at the eMagine Media Festival for my character model, Kopf, that I made in the first semester. I was within the top 5 of 9 submitted, and while I did not place in the top 3, after seeing the winners I was perfectly fine with not doing so. The work put into all of the pieces at the festival awed me, from web design to typography to documentary to character modeling. I was humbled to be considered among the nominees, and am greatly appreciative of the opportunity I had to partake in the festival. You can see several rotations of the model with varying render qualities below.

I will close on a broader reflection of my involvement with e-Comm as a whole. This will be my last year with the program, due to issues with class schedules and simply a lessened zeal for the material. I believe that I can apply what I have learned about accessibility and the basic principles of design to almost anything I do. I also greatly enjoyed learning about more niche elements of animation, like lighting and rendering in mental ray and designing characters in Maya (even if my work was somewhat rough). However, I do not believe at this point that I want to make a career out of this field. I simply lack the zeal for it I once did, and while I still greatly appreciate what I have learned, I just don't think that continuing with the program would be the best use of my time in high school. Now that I've learned the basics of things like organizing projects, creating accessible designs, and operating software like Photoshop and After Effects, I don't feel that deeper involvement with the program will help me more than other academic focuses. I am grateful for the friends I've made and instruction I've received, but I believe that it is best for me to leave the e-Communications program in order to further my new goals for life.