MOTION CAPTURE IN SUPPORTING CREATIVE ANIMATION DESIGN

Abstract

This research examined students' reveal of animation design creativity with the application of motion capture technology. By comparing two kinds of motion design method, traditional keyframe and motion capture, we investigated whether students' creativity in motion design would be supported by digital tool. The results showed that in animation exaggeration index, keyframe method had slightly higher performance support for designing unusual motions. Nevertheless, motion capture had shown more support in creating valid actions in quantity which implied creative fluency was achieved. Besides, in emotion category index, motion capture also revealed higher support for creating more emotion categories in the animation design. Participants indicated that keyframe method was helpful to design extreme poses that were not easily acted out by human beings. While motion capture method provided intuitive design tool; so they could create motions easily by performing out their ideas naturally and quickly.

Full text

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The Fourth International Conference on Design Creativity (4th ICDC)
Atlanta, GA, November 2nd-4th, 2016
MOTION CAPTURE IN SUPPORTING CREATIVE
ANIMATION DESIGN
Tsai-Yun Mou
1Department of Visual Communication Design, Southern Taiwan University of Science and
Technology, Tainan, Taiwan
Abstract: This research examined students’ reveal of animation design creativity with the
application of motion capture technology. By comparing two kinds of motion design method,
traditional keyframe and motion capture, we investigated whether students’ creativity in motion
design would be supported by digital tool. The results showed that in animation exaggeration
index, keyframe method had slightly higher performance support for designing unusual motions.
Nevertheless, motion capture had shown more support in creating valid actions in quantity which
implied creative fluency was achieved. Besides, in emotion category index, motion capture also
revealed higher support for creating more emotion categories in the animation design.
Participants indicated that keyframe method was helpful to design extreme poses that were not
easily acted out by human beings. While motion capture method provided intuitive design tool;
so they could create motions easily by performing out their ideas naturally and quickly.
Keywords: motion capure, keyframe, creativity, animation
1. Research Background
The creation of animation is a creative process. It starts from the story and art design in pre-production
stage, to motion design in production stage, and ends at the effects and sound design in post production.
The whole process involves artists, designers, and technical engineers to contribute their specialties to the
animation movies. In the production stage, technical artists have to understand animation designers’ needs
in order to create convenient and intuitive tools for them to do motion design. Therefore, the creation of
motion may have some limits because of the tool setting. Figure 1 shows the common/traditional 3D
animation pipeline in the production stage.
Figure 1. 3D production pipeline in the production stage

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Character rigging is a process of setting virtual bones and controllers for the character. Skinning is a
process that we modify each part of the model to match the affecting bone area. Hence, in character
rigging and skinning stage, it is a complex work that requires highly skills and user’s experience to design
an easy-to-use tool rig(O'Hailey, 2013). And in many cases, especially in short films, the rigging work is
also carried out by the animator. That is, animation designers have to do rigging, skinning and motion
design. This cumbersome work could distract animators’ attention on good motion design and extend the
production time. Figure 2 shows some example of 3D character rigging and skinning.
Figure 2. 3D character rigging and skinning
The design of motion is a process of creative performance design. Animators behind the computers have
to make the virtual characters alive with their acting skills. This concept also works for 2D hand-drawn
animation. What makes animation characters come to life depends on the animation
performance(Williams, 2012). The typical way of motion design is through “keyframe”. By manually
keyframing each control tool (rigging controller) in the character’s body, as shown in Figure 2, animators
can show their motion design skills and creativity. However, it is not always easy to keyframe the motion
with imagination. In many cases, animators have to collect video resources for their motion design
reference. And often times animators have to “act out” their desired motion themselves to catch the
timing and intended pose(Webster, 2012). Therefore, the typical way of motion design with manual
keyframing still has some gaps to fulfil the animators’ actual need(Terra & Metoyer, 2007). Since
animation design is about creating interesting and believable motions, it is necessary to eliminate rigging
or skinning restrictions that would limit the animators’ expression of creativity.
2. Motion Capture
2.1. Application Field
In film and animation productions, motion capture (MOCAP) technology has been applied widely for
years(Menache, 2010). The use of MOCAP can not only record fluent motions but also save production
time. Films like The Lord of Rings, Spiderman, and Avatar all take advantage of MOCAP’s features of
direct recording of motions. Nevertheless, the use of technology tools does not mean to replace the
traditional keyframe process. Instead, to incorporate MOCAP in animation pipeline can create more
believable and appealing motions, as the 12 principles of animation raised by Disney’s animators Ollie
Johnston and Frank Thomas mentioned in their book(Johnston & Thomas, 1995).
Besides in the entertainment field, motion capture is also used in medical or sport research to analyze
human’s movement(Kageyama, Sugiyama, Kanehisa, & Maeda, 2015; Mefferda & Cordera, 2014); in
behaviour science to study the relationships between people’s behaviour and violent games(Charles,
Baker, Hartman, Easton, & Kreuzberger, 2013); and in social science research to understand women’s
rigging controller
bone and skinning

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selection of men on the basis of body movement. These studies all take advantage of MOCAP’s
characteristic of “movement” recording and do further analysis. However, in animation field, besides
production application, there are few further researches that use MOCAP to investigate animation
fundamental study. MOCAP can be integrated in design education to assist learning and teaching. Hence,
here in this study we utilize the tool to uncover whether designers’ creativity in motion would be
enhanced by motion capture technology.
2.2. Related Studies
Previous studies on motion capture have mostly contributed to the integration of MOCAP and keyframe
techniques. In Bruderlin and Williams’ study, they developed a motion editing tool that could do motion
wrapping and motion signal process to combine MOCAP data with keyframe setting together(Bruderlin
& Williams, 1995). Popovi´c utilized motion transformation to simplify MOCAP data and keep the
freedom of traditional keyframe manipulation(Popovi´c & Witkin, 1999). Pullen developed a method that
could extract the fluent motion from MOCAP and tweak afterwards in virtual character(Pullen & Bregler,
2002). All of these researches which keep the fluent advantage of motion capture and retain the choice of
keyframe method are good examples of integration of motion design methods. Although advance in
method or technology can greatly help the animation production, it is still unknown whether MOCAP has
positive support for designers’ creative motion design. And this is our main goal to find out the
underlying phenomenon and reasons.
3. Digital Tool and Creativity
3.1. Digital Tool
The use of digital tools in education and production is a trend and irresistible mainstream. Previous
researches have indicated that digital tools or environments can have positive support for the design
process. Karakaya in their study of MOODLE have showed that collaborative digital environments can
increase social interaction. The discussion records of their idea generation, critiques, and sketches are the
main evidence of creativity in collaborative digital environments(Karakaya & Demirkan, 2015). Muldner
also agreed that digital technologies have the unique opportunity to support creative process in STEM
fields(Muldner & Burleson, 2015). In their study, they further utilized various sensing devices to model
students’ creativity in digital environment. Another study of digital technology also confirmed its’
advantages in enhancing innovation and implementation of the employees’ creative ideas(Oldham & Da
Silva, 2015). From the results of these researches, the use of digital tools in different domains have
proved to be effective in supporting people’s creative performance. Nevertheless, it is still unknown in
animation field besides production application, whether the use of motion capture will also sustain
animators’ creativity in motion design.
3.2. Design Creativity
Creativity is often regarded as an inherent part of design process(Taura & Nagai, 2011). Thus, in design
pedagogy it is often assumed to be included in teaching to raise students’ interests and motivation.
Nevertheless, the meaning and definition of creativity is not well understood by teachers(Morgan, Dunn,
Parry, & O'Reilly, 2004). It is necessary for teachers to have a concise definition of creativity in particular
task or project so students could have a clear vision of their learning activity. And teachers can also have
an objective framework to assess students’ performance.
J. P. Guilford, in his psychological model called “Structure of the Intellect”, used a factor analytic
technique to separate creative thinking skills from others. He claimed that creativity was generation of
ideas that were novel and appropriate to the field(Guilford, 1967). As part of this model, he identified two
distinct forms of thinking: divergent thinking and convergent thinking. Divergent thinking associates with
creative thoughts, or the ability to derive unique, multiple, and numerous answers to open-ended

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questions. Therefore, it is sometimes used as a synonym for creativity. Guilford operationally defined
creativity through four major factors, i.e., originality, fluency, flexibility and elaboration, which were put
into practice to assess individual creativity.
Originality implies statistical uncommonness of the total responses. In our animation design research,
here we set the creative index of exaggeration, which means magnification of some action, to match
originality factor because overstate of action is uncommon but critual to motion design. Fluency means
quantity of appropriate responses and this matches our index of amount of valid action. Flexibility
means variety of categories of appropriate responses. Therefore, in our experimental design, we set
emotion category to match this factor since a certain motion design can be expressed in various emotions,
which are also important to good animation. Elaboration implies amount of detail in the responses. This
creativity factor is not examined in our study though, because in animation it requires huge amount of
time to create a vivid motion that includes facial and body animation. This requires elaborative efforts
from a couple hours to days or weeks to finish only a few seconds in traditional keyframe animation.
4. Objectives
In order to investigate how digital tool can assist in creative animation design, our research questions and
goals are set as the following points. First, how MOCAP can support users’ design of motion especially in
the creative part? We will focus on the quantitative analysis of this question. Second, in what aspects that
users regard MOCAP as helpful in their design process of animation? To uncover this question, we will
do a qualitative study of users’ responses.
5. Research Method
The goal of this study is to find out how and in what aspects that MOCAP can support in creative
animation design. 30 college students from animation department joined in this experiment. Participants
all had 2 years of animation training in their curriculum and their previous academic performances were
B+ in average. They were randomly assigned to test group or control group for avoidance of bias. Test
group was equipped with the MOCAP system while control group had to design motion from pure
computer keyframe. Their experimental results, that is, motion design, were evaluated by 3 experts from
the animation industry. A five point Likert scale (1=strongly disagree, 5=strongly agree) was used to
examine the first index of animation design creativity, i.e., exaggeration, to see how participants could
create uncommon motion design. The second index was the amount of valid action, which we counted the
numbers of appropriate motions to the task. The third index was emotion category, which we counted
how many emotions in the motion designs. T-test analysis was conducted to examined the differences
between test group and control group. Interviews were also conducted with the participants afterwards to
further understand their thinking towards the utilization of motion capture system or the keyframe design
experiences. This research can further contribute to the animation design education and creativity
development.
5.1. Design Task
A good animation depends on various aspects of factors, such as story, art design, special effects, motion
design, etc.. Here in this study we focus on the “animated” part, which is the motion design. They were
asked to create interesting “walks” with the digital character. The smoothness of movement or quality of
the motion were not taken into consideration in this experiment, since we only examine the creativity of
the motion design. The elements for experts to judge creativity are exaggeration(originality), amount of
valid action(fluency), and emotion category(flexibility). Participants were provided with a digital
character to design and animate with(Figure 3). Before the task, they were explained about the research
goal of animation design creativity. Participants were encouraged to explore any possible motions as they
desired. Information provided to the participants are listed as the following points.

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 Motion task: interesting walk(s)
 Character: a digital animate-ready 3D character
Figure 3. 3D character
Participants were required to finish the design task within 60 minutes. This task was conducted
individually and followed by an interview when they finished the experiment.
5.2. Motion Capture System
The motion capture system that we used in this study was Animazoo IGS-180. It is a wearable and
portable Gyroscopes type of motion capture system. The system is consist of 17 OS3D miniature
orientation sensors (Figure 4) which can detect and record the actor’s motions. The sensors are located in
human’s main joints and head to represent and record the actor’s motions. Each of the sensor is
composed of tri-axial MEMS Gyroscopes, tri-axial MEMS Accelerometers, and tri-axial magneto-
resistive Magnetometers. The OS3D has onboard processor and embedded orientation algorithms that can
allow direct transmission of motion data wirelessly and show motion results in the system interface.
Figure 5 shows the basic structure and interface of the Animazoo IGS-180 MOCAP system. Participants
in the test group were trained on how to use the system to achieve their desired animation movement
before the task.
Figure 4. OS3D sensor
Figure 5. Structure and Interface of Animazoo IGS-180 System
wireless
transfer
17
embedded
OS3D

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6. Results and Discussions
6.1. Creativity in Motion Design
In the exaggeration index, test group(n=15) had average score of 2.93 while control group(n=15) was
3.40. The standard deviation of the exaggeration score was 0.59 and 0.50 for test and control group
respectively. There was significant difference(p=0.029 < 0.05) between two groups. This result implies
that keyframe method has better support for participants to express their creativity in the originality aspect.
The reason for motion capture to have lower score could because of its real acting from participants.
Since animation is recorded from their performance, it is possible that participants tended to act normally
or naturally without overacting of the motion. Figure 6 shows an example of creative and less creative
pose by keyframe and motion capture respectively. As we can see, keyframe showed asymmetry pose
which is more interesting and creative, while motion capture pose revealed simple but dull pose. This
phenomenon could because students’ acting for the acting’s sake without deep thinking of motion’
purpose.
Figure 6. Motion poses from keyframe and motion capture
With regard to the amount of valid action index, test group had in average 14.33 motions created and
control group had 4.8 motions instead. Motion capture had obviously a lot more valid actions created than
keyframe method. This phenomenon could because MOCAP has the characteristic of instant recording of
human’s motion, while keyframe is manually set through rigging controller. Thus, in a same period of
time, participants could create more motions with MOACP than with keyframe. This implies that motion
capture has positive support for fluency element of creativity. Participants’ fluency part of creativity
could be enhanced through digital tool.
In the emotion category index, test group had average of 4 categories and control group had 2.33 in
average. The reason for control group to have fewer emotion categories could be corresponding to the
amount of action. Motion capture which creates more actions would also have more emotions included in
the design. The emotions were more expressed in cheerful, sad, lazy, and angry mood. Since keyframe
method takes longer time to accomplish a motion design, most of its results fell into cheerful and sad
emotion. Reason could because these two moods are most common and be instantly thought of.
6.2. Participants’ Attitudes towards Motion Design
After the motion design task, each participant was interviewed to understand his/her experience and
attitude towards keyframe method or motion capture technology. Generally speaking, participants from
test group who used motion capture, they indicated that MOCAP was helpful for viewing what they did

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directly. It provided an intuitive way for them to “act out” the motion and see the result directly. Here we
extracted some interviews from test group.
 Participant A: “The tool is easy to use and I can create any motions I have in my brain.”
 Participant B: “It’s good to see what I have done immediately and act out the motion directly
without keyframing.”
Another feature that participants responded towards motion capture was “time-saving” in motion design.
Compared with keyframe method which participants had to manually set keys to pose proper movement,
motion capture has the advantage of recording body movement instantly and thus save time in production.
From their design results we can see that test group who used MOCAP produced more motions than
control group who created with traditional keyframe method. This fact is also revealed in the interviews.
 Participant C: “It is very easy to create motions in a short period of time. The tool is helpful to
automatically save my actions and thus I can create more animations by only focusing on
performance.”
 Participant D: “It is quite cumbersome to manually key each frame with the traditional method. It is
difficult to achieve my desired motion in a short time.”
The other positive point that participants mentioned about was the “fun and freedom” characteristic of
motion capture. To see what they had done immediately was a special experience for participants. The
instant recording provides a visual feedback of their performance. This feature could trigger participants’
interests and thus could further encourage them to make any possible designs as they think of.
 Participant E: “I’ve never thought of creating animation could be so fun. I enjoyed the process of
motion design which I could explore any poses as I like.”
 Participant F: “The tool is very handy and convenient. I don’t need to worry about setting
keyframes.”
Regarding traditional keyframe method, some participants revealed that “extreme poses” could be
achieved with keyframe. This response reflects what animators regard animation should contain, i.e.,
exaggeration(Williams, 2012). It is through over-acting of the movement that audiences could feel 3D
character alive and vividness.
 Participant G: “Posing the character in an extreme way makes him more vivacious. This is what
virtual character should contain in its pose.”
 Participant H: “One good thing about keyframe is its offer of flexible skeleton that I could
manipulate with. I don’t need to worry about breaking bones or unable to set extreme poses.”
7. Conclusions
Creativity in animation design is always an important point. Virtual characters’ motion design can be
achieved through traditional keyframe and motion capture technology. In this research, we found that
keyframe method was helpful in exaggeration of action, which implied originality element in creativity
was revealed. Motion capture, on the other hand, was more supportive in fluency and flexibility element
in creativity. Digital tool such as motion capture can increase motion designs in quantity and different
emotion categories. Both are also key components of creativity. Therefore, to develop students’ creativity
in motion design, it is suggested to utilize the combination of both methods in teaching. By using
keyframe’s exaggeration, we could guide students to understand animation design aesthetics which is the
fundamental knowledge. With the help of motion capture technology, we could increase students’

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interests and motivations in learning, and further explore more possible motion designs. Further research
could be on the design process of motion design, to investigate how keyframe/motion capture could assist
teachers and students in the teaching and learning feedback. Thus, we could utilize digital tool in a more
effective way.
Acknowledgement
This research was supported by Digital Media Lab in Southern Taiwan University of Science and
Technology. Greatly show my appreciations for the research funding, facility and participants to this
research.
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