| Article Focus: Morphing is a distinctive effect that is best known from the movie "Terminator 2" as well as the Michael Jackson music video "Black and White". In this tutorial, Chris Zwar demonstrates simple morphs with the Reshape filter in Adobe After Effects 5.5 -- which is a Production Bundle only effect found under the "Distort" menu. (Intermediate to Advanced) |
| Download Movie | Project files .sit | Project files: .zip |
 Morphing is a distinctive effect that is best known from the movie Terminator 2 as well as the Michael Jackson music video Black and White. After Effects can do simple morphs with the Reshape filter - which is a Production Bundle only effect found under the Distort menu. Basically, a morph consists of one image changing its shape over time until it becomes another image. Morphing can be used as a visual effect - for example an actor may morph into an alien - or as an invisible technique - for example to change the perspective of a miniature so it can be composited more accurately with live action. The morphing effects in Terminator 2 were sophisticated 3D models which altered their geometry in 3D space, and there is no way to achieve that level of sophistication in After Effects. However, simple morphing with 2D images is fairly straightforward, and if you're familiar with basic After Effects procedures they can be completed fairly quickly. A simple morph effect is actually three events happening concurrently:
If you are planning to shoot footage for a morph effect then the subjects should be shot greenscreen so they can be isolated on a transparent background. During a morph effect, the shape of the image is being altered. Unless the subject is isolated then elements in the background can also be distorted and warped which will undermine the appearance of the overall effect. While the Reshape effect can be limited to certain parts of your image by using a "boundary mask" (see below), it is still much easier if your subjects begin as keyed elements. Once the final morph is completed, then the rendered effect can be composited into a background plate. A really good morph will have source and destination images which are similar - not only in subject matter but also in composition. A morph of one actor into another will be much more effective if they both have the same stance and position in frame. Wildly different images will almost certainly give poor results. To demonstrate this process, we'll do a simple morph of a human into a sheep - I already had some greenscreen footage of a sheep from a TVC, and Jock (the editor from downstairs) volunteered to help before he knew what it was for. To make the morphing process as easy as possible, I prepared the source and destination footage so they would be as similar as possible. I keyed both elements, positioned them in frame so they occupied that same area of the screen, and used time-remapping so that their actions (turning their heads) matched as closely as possible. By using greenscreen source images, it is much easier to change the position and size of one subject to match another, because we don't have to worry about the background.
In order to minimize file sizes for the Internet, the source footage files were rendered with separate alpha channels. You will need to re-combine these in After Effects before beginning the tutorial – applying the alpha channel movie as a luma track matte for the respective footage file. You could continue the tutorial using these as precompositions, but for simplicity I recommend rendering them out as uncompressed Quicktimes. A project file to do this for you has been included as part of the tutorial. Begin by opening After Effects and importing the two Quicktime files: Jock-Source.mov and Sheep-Source.mov.(Download all the footage with the project file above in the green bar.) In the project window, drag one of the footage items onto the composition icon at the bottom of the window, so it creates a new composition at the same size and frame rate as the source file. The composition should be 320 x 320, square pixels at 25 fps. Change the composition settings to have a duration of six seconds, and then drag the other footage file into the composition. I called the composition "Reshape-Morph project" If you select the Jock layer in the timeline, pressing "i" will take you to the in-point. Using the pen tool, draw a mask around Jock and make sure it's closed. I find that it's easier to draw a mask when the image is greyscale, so I click on the green button at the bottom of the composition window so I'm only looking at the green channel. You may also find it easier if you zoom in to 200% or even more. Because Jock moves during the one second, we need to animate the shape of the mask to match his movement. Press "m" to reveal the mask properties in the timeline window, and click on the stopwatch. This will add a keyframe which records the shape of the mask at the 3:00 point. It's important to note that we only need masks to define the shapes we're going to morph - we don't need our masks to act as masks which cut out the background. So where it says “add”, select "none" from the mask menu to turn off the mask, otherwise we will be clipping fine detail from the edge of Jock's face. Clicking on the name of the mask – which by default is “Mask 1” and then pressing "enter" will allow you to rename the mask to avoid confusion later, so call it "Jock shape". Press the "o" key to go to the out-point of the Jock layer, which is 3:24. Using the selection tool, adjust the mask to match Jock's position in this frame. He hasn't moved very much and it's really only the profile of his face which needs to be changed. After Effects will automatically add another keyframe for the new mask shape, and it will animate the shape over time. If you scrub in the timeline, you will see that as the mask animates over the one-second period, it matches Jock pretty well. We don't need to adjust the mask any further. The next step is to do the same thing for the sheep layer. Draw a closed mask around the sheep, enable mask animation with a keyframe at 3:00 and then move to 3:24 and adjust the mask to match. Unlike Jock, the mask with only two keyframes doesn't fit the sheep that accurately as it animates, so at 3:10 and 3:20 you will need to tweak the shape of the mask to match the sheep's movement. Rename the mask to "Sheep Shape" and ensure the mask mode is “none” and not “add”. Once we have masks which outline our two subjects and animate over time to match their movement, we can begin on the actual morph effect. Copy and paste each mask onto the other layer, so that both our layers have both masks. Rename the layers once you've pasted them (they default back to “Mask 2”) and turn them off by selecting "none" from the mask menu. In the composition window, you should now see the shapes of the two masks overlapping our footage items. The first thing we need to do is change the defaults. Change the "source mask" to "Jock Shape". This is our starting point - we are defining which parts of the image we want to morph. The "percent" slide is what we animate to control the morph - and if you experiment by sliding it you will see that we can make Jock look remarkably interesting. However, at 100% Jock doesn't look as good as he could. This brings us to the most critical aspect of a good morph - correspondence points. For our morph effect to look great, we want Jock's features to match the Sheep's as much as possible during the transition. We need to tell After Effects which part of Jock will become which part of the Sheep. To do this, we will use "correspondence points" to tell After Effects which parts of the mask around Jock correspond to the mask around the sheep. By default, applying the Reshape effect only gives us one pair of correspondence points, but for a shape this complex we will be needing between 20 and 30 pairs to make our morph look really good. The quality of the final morph effect depends much more on the accuracy of the correspondence points than the accuracy of the masks. Adding correspondence points is quite slow, but we can make it easier on ourselves by taking some preliminary actions.
The outcome of the effect is highly dependent on correspondence points - especially the direction of the vectors. Even small changes to the position of two points can have a very big impact on the outcome.
You may wish to adjust the positioning of some of the correspondence points to match features visible in the image. If you turn the Reshape effect on, and set the percent to "100", you can see how Jock is warped to fit the shape of the sheep. Preview the animation, and tweak the position of your correspondence points until you're happy with the effect. Now we have to do the same for our sheep layer. It is possible to copy and paste the Reshape effect from the Jock layer, but be warned that the correspondence points don't always paste accurately, so usually it's quicker to begin from scratch. Apply the Reshape effect to the sheep layer and change the Source shape to Sheep Shape, the destination to Jock Shape, and the boundary mask to none. As we did with the Jock layer, add correspondence points around the two shapes (by holding down the option key), change them to smooth interpolation (by holding down the shift key), and adjust their position to match corresponding features (by sliding them around the masks). At any time you can turn on the layer visibility and the effect to check your progress, but it's pretty slow. It is easier and certainly faster for us to render out our two layers as separate movies, and continue working on the rendered layers. In the Reshape effect window, the "elasticity" pop-up determines the quality of the render, at the cost of speed. For the rendering, I chose "loose", but if you have a lot of time on your hands then there's no reason not to use "super fluid". At lower settings, the warped areas can appear pixilated and blocky, although renders are faster. Despite the descriptive nature of terms such as "loose" and "liquid", there isn't a stylistic difference between the different settings - it's the same algorithm just with different levels of precision. Each setting takes approximately twice as long to render as the previous setting. The transition between these two effects is just as critical to the overall effectiveness of the morph. You can do a simple dissolve by only animating the opacity, but the effect can be made much more dramatic by using transitions like ripple dissolves or even FE Light Wipe (if you have it). To simplify things, we'll set up another composition just to do the transition. In the Project window, select our current composition and duplicate it. Change the name of the duplicate composition to "Reshape - Morph Transition". Basically you're re-creating your composition but using the rendered files instead of layers with masks and effects applied. To reveal the morph, you can use any transition effect you like, but in this case we'll use a gradient wipe so that the luminance of our sheep layer will control the change in opacity. It looks good and enhances the warping effect. Select the sheep layer and apply the “Gradient Wipe” effect from the Transition menu. In the "gradient layer" pop-up menu, select the second sheep layer- which is the one we've just applied the effect to. This makes the opacity of the sheep layer follow the luminance of the image over the duration of the morph effect. Set the "transition softness" to 50%, or whatever value you prefer.
In our case, we have defined Jock and the Sheep (that's a good name for a Cop show) by a single mask. Their entire heads and bodies morph together, as a single image. The next step into making this a more complicated looking effect would be to use our current project as a base, and build up more layers to deal with each feature of their faces. In this way, you could have another pair of layers which only mask their eyes, and other for their ears, and another that might just deal with their noses. In this way, you could build up a complicated effect where Jock’s eye morphs into the Sheep’s eye, his ear becomes the Sheep’s ear, and his nose becomes the Sheep’s nose. You would also be able to individually tailor the rate of change of each of these elements by adjusting the velocity curves of the “percent” slider so each element warps at a different rate. It all depends on how much patience you have. |
