Rotoscoping - Triple The Buck

For this session we needed to have the following resources prepared:
One clip running at 12 to 25 fps to a maximum of 1-second long and a vector illustrated background. Something we needed to consider when choosing our clip to use was firstly that it could be used within a loop, secondly to ensure that the subject wouldn’t be obscured by anything, as we were to crop the subject out. Another point to be aware of was motion blur, as if the clip had motion blur this would make it very difficult to crop out our subject effectively. 

I looked on the Internet for stock footage and found it quite difficult to find something that both interested me and was suitable while also being free to use. I eventually found a video clip of a buck though this wasn’t looped; there is a moment where the buck moves its head. I decided to crop this section out, duplicate it and combine them both together to create the loop. I then create a simple cleared forest background, using Illustrator. As you can see I have used the “Time-Reverse Layer” option to reverse the duplicate clip as shown

The film used was sourced from the following website: beachfrontbroll.com.

Time-Reverse Layer

To start the session we were shown an example of rotascoping as seen within the Kylie Minogue video “come into my world”. In this example there is a very high level of detail and skill in terms of cut-outs applied within the video and synchronised in order to effectively overlap and interplay against one another. The main subject who is duplicated is that of Kylie, though as the video gets further in it becomes clearer that the background characters are also being replicated in sequence.

We all began by opening Adobe After Effects and importing our files. In my case I was using a video file and so needed to import the file as footage, which is typically how things are imported within after effects. However if I was to be using a selection of still images, for instance as used within gif images, I would then be required to import this as a “Jpeg Sequence”. The general composition settings are to be that as typically used, full HD, square pixels and the frame rate to be set at 25fps.

Stretch tool

The duration of the clip was set at 2 seconds as it needed to be short for this task. You have the choice of either rotoscoping on a frame-by-frame basis or as is typically used, animating on ones or twos. The most common method used in animation is animating on twos as this requires less time and speeds up the animation process. In order to create “twos” within after effects, we used the “Time Stretch” tool to create an equivalent. This is achieved by right-clicking the video layer and selecting Options>Columns>Stretch, then setting the stretch factor to 200% and hold in place to “layer in-point”, therefore doubling the frames. This is why our clip needed to be no longer then 1 second, as if it were the composition duration would need adjusting accordingly and further time spent on the exercise required.

Disabling the preserve constant
vertex and feather option.

Before we start creating our mask in order to isolate the Buck from the video, we first need to go to Adobe After Effects>Preferences in the main software settings and under the general tab deselect “Preserve Constant Vertex and Feather Point Count when Editing Masks”. The effect this has on our mask is that we can now alter the points on each individual frame and therefore have greater accuracy in cutting the subject out.

Masking

Now for the tricky part, this is the most time consuming element within the rotoscoping session and dependant on the shape of and backdrop to your chosen subject depends on how tricky it may be to cut out of each frame. I set the mask to a bright colour in order to make it clear to see each anchor point and line. Firstly you need to select the mask’s stopwatch before beginning as to prevent the alteration of the mask throughout affecting the original frame. If you find irregular keyframes there is a simple trick to enable a smooth animation. With the mask’s name selected and holding down the ctrl button, right-click the keyframe and select “Toggle Hold Keyframe”.

Expressions Pre-Built Coding

Now we have our subject ready to place within the main setting, create a new composition, but with the duration of 10 seconds and this will be our main composition to which we will output the video. I now imported and placed the vector background I had created within After Effects. I wanted to be able to place a Buck behind one of the trees and so rather then importing as “footage”, I imported the Illustrator file as a composition as to retain the separate layers. The next step was to place the buck into the composition and set to loop for the duration of the video. In order to enable the looping of the clip we need to use some time remapping tools. Firstly we needed to select the layer we wanted to loop and then go to Layer>Time>Enable Time remapping, before then opening this setting up and using the “play” icon, which refers to the expressions tool within the layers switches. When in this set of expression pre-built coding we need to select the one named “loopOutDuration” this will tell After Effects to continue the loop throughout. Using this device we can speed up or slow down a composition also, though in this instance we just want to loop the clip without the final frame blanking out.

Mixture of video rotoscoping and rotoscoping using a Trkmat

In order to bring up the expressions coding for the time re-map you need to hold down the alt key as you select the stopwatch. The final step here is using trkmats as I was taught in the first After Effects lesson of this year in order to give texture and/or an alternative colour to the shape we have cut and placed into the composition.

How did you find it?

I imagined this session to be difficult in terms of patience and only really found the actual mask creation and alterations to be tricky, luckily due to the scenery and distinction of the subject I chose this wasn’t too difficult. However I can imagine the patience larger and more detailed rotoscope projects could involve. Overall I found this session to be very useful and plan to create a further experiment in the near future using these techniques.

In regards to my outcome, I decided to use a mixture of the subject as it appeared within the video and also using the trkmat to give it a matte block colour. I chose to do this as to create juxtaposition within the piece showcasing the skills learnt in the session. I am very pleased with my final outcome, although there are a few small areas caught by the mask and feel the soft colours' I chose to represent the forest backdrop worked well in this instance.

Outcome

Rotabuck from Nicole H.D.W. Sinclair on Vimeo.