Tutorial: 2.5d Animation

Interactive Tutorial Content

To view the tutorial video for 2.5d Animation, the prize winning video Polar Classic, and download project files to work along with the tutorial, click here.

Producing The Polar Classic Animated Music Video

The Polar Classic, by Mark Wickman, was the 1st Place winner in Videomaker’s 2005 Short Video contest, in which Mark made an animated video, using still
photos. We’ve received many letters
asking “how did he DO that?” So we asked him to create a tutorial on just how the process is done. We discovered that the end results actually depend on the beginning… in the planning stage.

The Polar Classic is an annual golf tournament held the last week of February in Beijing. The client had a simple request: produce an interesting music video portraying this fun but competitive event, including footage of all the participants. I shot still photographs, and the client would later provide more than twelve hours of DVCPRO footage from the event.

I confirmed the animated stills approach after spending several hours viewing the video footage, which was not very exciting. I selected the 100 best photos and brought them to life, using a two-step process:

1. Preprocessing each photo into layers in Photoshop
2. Creating a short animation using those layers in After Effects

Pre-Production

As always, pre-production is key. One must “shoot to animate.” Some keys thoughts on this approach:

1. Take good photos or hire someone to do so (after
   explaining to them your animation approach and
   workflow). You are not going to fix bad photos in post.
   You are also not going to add motion in post to photos that don’t lend themselves to motion.
2. Think in layers. Understand the foreground and back-
   ground objects in each photo.
3. Understand motion. Look for shots with objects or
   behavior that are candidates for motion in the
   animated frame.
4. Shoot for a large depth of field and avoid blur in the
   photos. We can add this in After Effects.
5. Avoid legs. Full-body shots normally imply someone
   is going to walk by – difficult to animate. Shoot above
   the waist and simulate the walk cycle.
6. Variety is the spice of life. Almost every shot of every
   person in Polar Classic is at a different point on the
   golf course, something that was very much lacking in
   the video footage.
7. “Filling the hole.” You are going to have to fill in the
   holes behind your subjects, using Photoshop before
   you animate in After Effects. If you have complex
   geometry behind a subject, take a second shot of the
   background only.
8. Don’t forget the supporting shots: ball in a sand trap,
   flag in the hole, green grass, golf ball closeup. If you
   are shooting a wedding, shoot all the usual supporting
   shots: ring, ring on finger, hand and pen, guestbook,
   knife and cake, rice in hand.

Photos: Selection and Processing

I selected and processed 100 of approximately 300 stills shot at the event. That represents an ideal shooting ratio compared to the video alternative.

If you have some music in mind, understand its length and beats per minute in order to calculate the number of photos you need. If you are uncertain, tap it out. Polar has a fairly punchy progression: one hundred photos at three seconds for most of the animations. On some wedding videos, I have used a mix of video and longer animations to good effect.

I always shoot JPG format. With today’s DSLRs, you have more than enough resolution for a beautiful PAL or NTSC image. I suggest pre-processing all of your images to the same size, orientation and file type, if they are not consistent. If you need adjustments to clean up your images, do this in Photoshop before the processing described at right.

When selecting photos, make brief notes on your layering approach and potential layer motions. A two-person approach for dividing the layering and animation work was very effective, enabling us to deliver this project quickly – three weeks from event to DVD.

Objects in your photos need to be isolated into Photoshop layers for animation in After Effects. The Photoshop work represented 35-40% of the total project hours. We used this simple process to create the PSD files for each of our photographs:

1. Open the selected still photo in Photoshop.
2. Convert the original JPG file to a layer called
   Original.
3. Duplicate the original layer and call it BG.
4. Duplicate the original layer again for each of
   the object layers which will be animated, i.e., FG
   (foreground).
5. Order the layers so the object layers are on top above
   the BG layer, with the Original layer on the bottom.
6. Process the FG and BG layers to isolate the object:
   1. Select the FG layer and make sure only it is visible.
   2. Use polygon lasso tool to cut out the object; zoom
      in on the layer to make this easier using a 1px
      feather and anti-alias.
   3. When selection is complete, inverse the selection
      and erase the background. You now have an FG
      layer ready to be animated.
   4. With the selection still in place, change to the BG
      layer and make it the only visible layer. Inverse
      the selection again to select the FG object, and
      erase it to create a hole in the BG layer
   5. Use the clone stamp tool to fill the hole. There are
      various techniques to accomplish this: copying
      from the same photo, stealing from another pho-
      to, inserting new objects, using the second photo
      you shot of background only.
   6. Save the PSD for After Effects. Turn visibility on
      for all your FG and BG layers and off for the
      Original layer.

The Polar Classic project contains subjects in front of their actual backgrounds – that is to say, we cut everything out (step 6c). If you have subjects who can pose, green screen is worth considering; you can then composite the keyed subject onto photographed backgrounds. If you haven’t tried pulling a key on your DSLR, try it – it sure beats the shortcomings of DV!

Most of the PSD files for the Polar Classic animation consisted of 3 simple layers: Original, FG and BG. A notable exception was the title shot. This title animation consists of 70 or 80 layers, mainly golf balls, putted across a putting green to ultimately form the title of the video.

Caption: A great deal of time and effort goes into prepping your layers in a photo editing software. Create a system for naming your layers that works for you and for interpreting them in After Effects.

Animation

Subtlety sells. Small relative movements, soft shadows and very gradual depth-of -field effects go a long way to represent reality. Almost all of the 100 animated stills used in Polar Classic employ combinations of the following effect categories on the individual Photoshop layers:

1. Depth of field (simple blurs or the more complex
   3d+camera approach)
2. Translation
3. Rotation
4. Warps, flares, grain or complex blurs
5. Simulating a camera move
6. Camera jitter
7. Shadows and lighting

Here is a summary of the general workflow:

1. Create an AE project. I work on sets of ten photos
   within each AE project, creating a separate composi-
   tion for each of the PSD files representing each indi-
   vidual photo. I applied animation techniques to each
   of the layers within the compositions.
2. Create a composition within the project and import
   the associated PSD file. Most compositions in Polar Classic were three seconds long.
3. Scale each layer down so it fills the PAL or NTSC
   frame.
4. Apply effects to each of your layers.
5. Render out your final MOV or AVI file for use in
   compositing application later.

The following covers three examples of the After Effects compositions, which include most of these effects classes.

Depth-of-Field Effect

One of the most subtle and powerful effects is using a depth-of-field change to direct the viewer toward your key subjects. This example shows how you can animate blurred keyframes on FG and BG layers to simulate a camera’s method of selective focus. The Position keyframes, created by a wiggle effect, simulate the two people walking. The Scale keyframes simulate a simple camera zoom by enlarging the objects over time.

Caption: Animating a Blur effect can simulate a shallow depth of field between multiple layers.

Simulating a Moving Camera

As the original layers have much higher resolution than our PAL or NTSC frames, we have plenty of pixels to play with. Animating the position and scale keyframes of the FG and BG layers in AE can help us achieve a moving camera effect (parallax).

The above example shows the use of position keyframes on FG and BG layers to move the layers in X and Y. Animate the scale keyframes equally on the two layers to achieve a zoom-in effect.

Play close attention to the anchor point of each layer as you animate the scale and rotate properties.

These approaches to creating movement and depth of field are a much lighter approach than using 3d layers and cameras. For multiple layers and complex movements, the latter approach will be superior.

Caption: Setting your layers into a coordinated motion will simulate a camera move.

Complex Layer Compositions

The next example shows the original Polar Classic title screen on the left and the underlying AE composition on the right.

We processed the underlying base photo of golfers on a putting green in many layers. We animated five of the golfers so that they each putt golf balls across the green to spell out the title when the balls rest in their final position.

The FG objects in the PSD layers consist of:

1. A layer for each golf ball which will be putted.
2. A layer for the putter of each golfer who will putt the balls. This is required so the putter can “swing” to propel each ball.

To create the BG layer, the putters (but not the arms of the players) were removed from the original photograph. Note that in the AE composition, simple position keyframes are used for the starting and finishing golf ball positions, along with scale keyframes to sell the effect of the balls moving closer. Rotation keyframes are used on the putter layers (anchor point set at the wrists) to simulate the putter motion.

After Effects has an amazing set of effects and tools to accomplish most shots. How would you accomplish a shot of a golf ball rolling on the green and dropping in the hole? Check the online tutorial to see how we handled this shot in Polar Classic.

Caption: In After Effects, compositions can become difficult to manage, such as in the golf ball title above, with many different layers. Embed compositions of more complex animations to simplify your work space.

Compositing

With all of your AE compositions rendered out, compositing is very straightforward. Each animation stands on its own, so I avoided dissolves between the shots. The main task in the compositing application is to sequence the animated clips.

Keep your original stills, your PSD files, the AE projects and your rendered animations well organized. You will usually find yourself often going back to tweak animations and then previewing the final results within your compositing timeline.

I hope you find these techniques useful in your ongoing quest to produce more compelling content.

Caption: Use music and sound effects to help tie together your animation sequences.

Mark Wickham’s Polar Classic was a First Prize Winner in the 2005 Videomaker/Digital Juice Short Video Contest.