This is an excerpt from Hybrid Animation by Tina O’Hailey. In Hybrid Animation, Tina discusses integrating 2D and 3D assets into a single project.
In this example we will put together a scene with 2D and 3D assets (and review key considerations when deciding whether the 3D or 2D asset leads the scene). While going through this hands-on portion, we will cover some of the pipeline issues: registration, timing, and line look. We will also look at various ways to combine 2D animation on top of 3D images. From these methods you can find what fits your pipeline best or come up with one of your own. Remember to post your findings on the forum at www.hybridanimation.com. You can read more information in the book about the forum.
In the first scene we will do, a small character climbs into the hand of a larger character and is lifted. You can use Iron Giant as your reference. The first question to ask then is, “Who leads?” In other words, whose movement is moving the other? In this case, the larger character will be lifting the smaller character; herefore, the larger character leads. Which one is which medium? The boy character will be 2D and the robot character will be 3D. So in this case, 3D will lead 2D. Please visit Chapter 3 in the Gallery section at www.hybridanimation.com for images displaying the pipelines that we will need to use.
This pipeline has 2D animation being done digitally. This means using Photoshop, Corel Painter Draw, Toon Boom, etc. You can draw with a Wacom tablet or use a Cintiq tablet. It isn’t advisable to think about 2D animating with a mouse. I’m sure it can be done, but I wouldn’t want to do it.
What if you do not have a fancy Wacom tablet and needed to draw the 2D on paper? Then you would need to print the 3D animation, peg it up, and use it as reference for your 2D animation. It is a cheap pipeline, but it instantly causes registration issues at the printing stage. The 3D character is printed onto paper. That paper is hand-pegged, meaning someone sits at a light table, lines up crosshairs that were printed on the animation, and tapes a peg strip at the bottom of the page. One by one each page is pegged up. A pencil test is shot to see if the pegging process was acceptable. Then the animator can begin to animate using the 3D images as reference. Once completed, the 2D animation needs to be scanned back in to composite with the 3D animation.
Beware. The printing and scanning process adds more time to your pipeline and most likely introduces bad registration between your 2D and 3D characters unless absolute care is given to the pegging process.
You might ask, “What if the order were reversed? What if the boy character was 3D and the robot character was 2D?” Then we would need to use a pipeline where 2D leads 3D. I’ve added the option of the 2D being traditional paper or digital. When traditional paper 2D leads, it isn’t as problematic unless the last stage of tweaking 2D to 3D is needed. In that case, there would be aprinting and pegging of the 3D assets and possible registration issues.
In scenes where one character is definitively leading the other one, it is an easy pipeline. However, what if this scene was a dance or a fight between characters? What if they had to tango? That would take more coordination between animators. More than likely one animator would lead and rough in where he or she expected the other character to be. The second animator would then take over and match where the first animator indicated the character to be. If there were any discrepancies, there would have to be a back and forth between the animators.
Anytime the animation goes from one animator back to the other for tweaking, it can be considered a redo. It costs extra time and usually worries the art production manager. It is the first part of the pipeline to be avoided. That does mean that usually each animator has only one shot to get the acting, registration, and timing correct and hope it matches to the character’s animation. However, if it is an “A” scene (a scene that is very important, like a moment scene with high emotion and story importance) or a scene where no discernable character leads the other, then the redos/tweaking should be allowed (within reason) to make sure the animation is acceptable.
Remember, any tweaking between media means much more time will be needed to finish the scene. Factor that in when you are budgeting time for your personal films.
Tina O’Hailey works at the Savannah College of Art and Design’s Atlanta campus as the Associate Chair of Animation. She has taught as a professor at SCAD since 2006. Prior to being a full time professor she was the artistic trainer at Walt Disney Feature Animation’s Florida studio, Dreamworks and Electronic Arts – Tiburon studio. She has been involved with many feature animation titles, including: Brother Bear (2003), Lilo and Stitch (2003), Mulan (1998), and Prince of Egypt (1998).