2023Activity reportProject-TeamANIMA

2.1 Understanding stories

Stories can come in many forms. An anatomy lesson is a story. A cooking recipe is a story. A geological sketch is a story. Many paintings and sculptures are stories. Stories can be told with words, but also with drawings and gestures. For the purpose of creating animated story worlds, we are particularly interested in communicating the story with words in the form of a screenplay or with pictures in the form of a storyboard. We also foresee the possibility of communicating the story in space using spatial gestures. The first scientific challenge for the ANIMA team is to propose new computational models and representations for screenplays and storyboards, and practical methods for parsing and interpreting screenplays and storyboards from multimodal user input. To do this, we reverse engineer existing screenplays and storyboards, which are well suited for generating animation in traditional formats. We also explore new representations for communicating stories with a combination of speech commands, 3D sketches and 3D gestures, which promise to be more suited for communicating stories in new media including virtual reality, augmented reality and mixed reality.

2.2 Authoring story worlds

Telling stories visually creates additional challenges not found in traditional, text-based storytelling. Even the simplest story requires a large vocabulary of shapes and animations to be told visually. This is a major bottleneck for all narrative animation synthesis systems. The second scientific challenge for the ANIMA team is to propose methods for quickly authoring shapes and animations that can be used to tell stories visually. We devise new methods for generating shapes and shape families, understanding their functions, styles, material properties and affordances, authoring animations for a large repertoire of actions, and printing and fabricating articulated and deformable shapes suitable for creating physical story worlds with tangible interaction.

2.3 Directing story worlds

Lastly, we develop methods for controlling virtual actors and cameras in virtual worlds and editing them into movies in a variety of situations ranging from 2D and 3D professional animation, to virtual reality movies and real-time video games. Starting from the well-established tradition of the storyboard, we create new tools for directing movies in 3D animation, where the user is really the director, and the computer is in charge of its technical execution using a library of film idioms. We also explore new areas, including the automatic generation of storyboards from movie scripts for use by domain experts, rather than graphic artists.

3.1 Geometric modeling of story worlds

Scientist in charge: Stefanie Hahmann

Other participants: Rémi Ronfard, Mélina Skouras

We aim to create intuitive tools for designing 3D shapes and animations which can be used to populate interactive, animated story worlds, rather than inert and static virtual worlds. In many different application scenarios such as preparing a product design review, teaching human anatomy with a MOOC, composing a theatre play, directing a movie, showing a sports event, 3D shapes must be modeled for the specific requirements of the animation and interaction scenarios (stories) of the application.

We will need to invent novel shape modelling methods to support the necessary affordances for interaction and maintain consistency and plausibility of the shape appearances and behaviors during animation and interaction. Compared to our previous work, we will therefore focus increasingly on designing shapes and motions simultaneously, rather than separately, based on the requirements of the stories to be told.

Previous work in the IMAGINE team has emphasized the usefulness of space-time constructions for sketching and sculpting animation both in 2D and 3D. Future work in the ANIMA team will further develop this line of research, with the long-term goal of choreographing complex multi-character animation and providing full authorial and directorial control to the user.

3.2 Physical modeling of story worlds

Scientist in charge: Mélina Skouras

Other participants: Stefanie Hahmann, Rémi Ronfard

When authoring and directing story worlds, physics is important to obtain believable and realistic behaviors, e.g. to determine how a garment should deform when a character moves, or how the branches of a tree bend when the wind start to blow. In practice, while deformation rules could be defined a priori (e.g. procedurally), relying on physics-based simulation is more efficient in many cases as this means that we do not need to think in advance about all possible scenarii. In ANIMA, we want to go a step further. Not only do we want to be able to predict how the shape of deformable objects will change, but we also want to be able to control their deformation. In short, we are interested in solving inverse problems where we adjust some parameters of the simulation, yet to be defined so that the output of the simulation matches what the user wants.

By optimizing design parameters, we can get realistic results on input scenarii, but we can also extrapolate to new settings. For example, solving inverse problems corresponding to static cases can be useful to obtain realistic behaviors when looking at dynamics. E.g. if we can optimize the cloth material and the shape of the patterns of a dress such that it matches what an artist designed for the first frame of an animation, then we can use the same parameters for the rest of the animation. Of course, matching dynamics is also one of our goals.

Compared to more traditional approaches, this raises several challenges. It is not clear what the best way is for the user to specify constraints, i.e. how to define what she wants (we do not necessarily want to specify the positions of all nodes of the meshes for all frames, for example). We want the shape to deform according to physical laws, but also according to what the user specified, which means that the objectives may conflict and that the problem can be over-constrained or under-constrained.

Physics may not be satisfied exactly in all story worlds i.e. input may be cartoonish, for example. In such cases, we may need to adapt the laws of physics or even to invent new ones. In computational fabrication, the designer may want to design an object that cannot be fabricated using traditional materials for example. But in this case, we cannot cheat with the physics. One idea is to extend the range of things that we can do by creating new materials (meta-materials), creating 3D shapes from flat patterns, increasing the extensibility of materials, etc.

To achieve these goals, we will need to find effective metrics (how to define objective functions that we can minimize); develop efficient models (that can be inverted); find suitable parameterizations; and develop efficient numerical optimization schemes (that can account for our specific constraints).

3.3 Semantic modeling of story worlds

Scientist in charge: Oliver Palombi

Other participants: Rémi Ronfard, Nicolas Szilas

Beyond geometry and physics, we aim at representing the semantics of story worlds. We use ontologies to organize story worlds into entities described by well defined concepts and relations between them. Especially important to us is the ability to "depict" story world objects and their properties during the design process 16 while their geometric and material properties are not yet defined. Another important aspect of this research direction is to make it possible to quickly create interactive 3D scenes and movies by assembling existing geometric objects and animations. This requires a conceptual model for semantic annotations, and high level query languages where the result of a semantic query can be a 3D scene or 3D movie.

One important application area for this research direction is the teaching of human anatomy. The Phd thesis of Ameya Murukutla focuses on automatic generation of augmented reality lessons and exercises for teaching anatomy to medical students and sports students using the prose storyboard language which we introduced during Vineet Gandhi's PhD thesis 30. By specializing to this particular area, we are hoping to obtain a formal validation of the proposed methods before we attempt to generalize them to other domains such as interactive storytelling and computer games.

3.4 Aesthetic modeling of story worlds

Scientist in charge:Rémi Ronfard

Other participants: Stefanie Hahmann, Mélina Skouras, François Garnier

Data-driven methods for shape modeling and animation are becoming increasingly popular in computer graphics, due to the recent success of deep learning methods. In the context of the ANIMA team, we are particularly interested in methods that can help us capture artistic styles from examples and transfer them to new content. This has important implications in authoring and directing story worlds because it is important to offer artistic control to the author or director, and to maintain a stylistic coherence while generating new content. Ideally, we would like to learn models of our user's authoring and directing styles, and create contents that matches those styles.

Arts and entertainement

Animated story worlds are central to the industries of 3D animation and video games, which are very strong in France. Designing 3D shapes and motions from storyboards is a worthwhile research goal for those industries, where it is expected to reduce production costs while at the same time increasing artistic control, which are two critical issues in those domains. Furthermore, story is becoming increasingly important in video games and new authoring and directing tools are needed for creating credible interactive story worlds, which is a challenge to many video game companies. Traditional live action cinematography is another application domain where the ANIMA team is hoping to have an impact with its research in storyboarding, virtual cinematography and film editing.

Performance art, including dance and theater, is an emergent application domain with a strong need for dedicated authoring and directing tools allowing to incorporate advanced computer graphics in live performances. This is a challenging application domain, where computer-generated scenography and animation need to interact with human actors in real-time. As a result, we are hoping that the theater stage becomes an experimental playground for our most exploratory research themes. To promote this new application domain, we are organizing the first international workshop on computer theater in Grenoble in February 2020, under the name Journées d’Informatique Théâtrale (JIT). The workshop will assemble theater researchers, artists and computer engineers whose practice incorporates computer graphics as a means of expression and/or a creative tool. With this workshop, our goal is to create a new research discipline that could be termed “computer theater”, following the model of computer music, which is now a well established discipline.

Education

Teaching of Anatomy is a suitable domain for research. As professor of Anatomy, Olivier Palombi gives us the opportunity to experiment in the field. The formalization of anatomical knowledge in our ontology called My Corporis Fabrica (MyCF) is already operational. One challenge for us is to formalize the way anatomy is taught or more exactly the way anatomical knowledge is transmitted to the students using interactive 3D scenes.

Museography is another related application domain for our research, with a high demand for novel tools allowing to populate and animate virtual reconstructions of art works into stories that make sense to museum audiences of all ages. Our research is also applicable to scientific museography, where animated story worlds can be used to illustrate and explain complex scientific concepts and theories.

Industrial design

Our research in designing shapes and motions from storyboards is also relevant to industrial design, with applications in the fashion industry, the automotive industry and in architecture. Those three industries are also in high demand for tools exploiting spatial interaction in virtual reality. Our new research program in physical modeling is also applicable to those industries. We have established strong partnerships in the past with PSA and Vuitton, and we will seek to extend them to architectural design as well in the future.

5.1 Footprint of research activities

ANIMA is a small team of four permanent researchers and three PhD students, so our footprint is limited. We estimate that we run approximately twelve computers, including laptops, desktops and shared servers, at any given time.

Research in computer graphics is not (yet) data intensive. We mostly devise procedural algorithms, which require limited amounts of data. One notable exception is our work on computational editing of live performances, which produces large amounts of ultra high definition video files. We have opted for a centralized video server architecture (KinoAI) so that at least the videos are never duplicated and always reside on a single server.

On the other hand, our research requires prowerful graphics processing units (GPU) which significantly increase the power consumption of our most powerful desktops.

The COVID19 crisis has changed our working habits heavily. We have learned to work from home most of the week, and to abandon international travel entirely. This holds the promise of a vastly reduced footprint. But it is too early to say whether this is sustainable. While the team as a whole has been able to function in adverse conditions, it has become increasingly difficult to welcome interns and Masters students.

5.2 Impact of research results

Our research does not directly address social and environmental issues. Our work on 3D printing may have positive effects by allowing the more efficient use of materials in the production of prototypes. Our work on virtual medical simulation and training may provide an alternative in some cases to animal experiments and costly robotic simulations.

Our most important application domain is arts and culture, including computer animation and computer games. Globally, those sectors are creating jobs, rather than destroying them, in France and in Europe. The impact of our discipline is therefore positive at least in this respect.

We are more concerned with the impact of the software industry as a whole, i.e. private companies who implement our research papers and include them in their products. We note a tendency to increase the memory requirements of software. While much effort in software engineering is devoted to improving the execution speed of graphics programs, there is not enough effort in optimizing their footprint. This is an area that may be worth investigating in our future work.

6.1 Sabbaticals

Stefanie Hahmann spent 10 months abroad within the framework of a CRCT granted by INP and a delegation granted by INRIA.

She visited during 5 months the University of Leipzig, where was was a guest of Professor Gerik Scheuermann. The main reserach project was on geometric design of auxetic metamatriels.

She spent the other 5 month at the FU Berlin as a guest of Professor Konrad Polthier. Research includes topics on approximation of freeform surface by developable ribbons. Within this period, she was invited to give talks at TU Freiberg, TU Dortmund and Univ. Leipzig,TU Berlin and FU Berlin.

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7.1 The Hitchcock Experience - a Spatial Montage project.

Participants: Rémi Ronfard.

Hitchcock experience

As a result of a successful collaboration between Phd Student Rémi Sagot-Duvauroux at EnsadLab and master student Nils Quaetaerts at Ecole Polytechnique, we published a new paper in the "spatila montage" series exploring the generalization of classical montage theory to the emerging technology of "room scale VR" 10. We take the emblematic plane sequence in Alfred Hitchcock's "North by Northwest" and invite the spectator to experiment it "from the inside". This raises interesting research issues. How to inhabit this cinematic story world? How can the traditional tools of cinematography and montage be used to direct the audience in this new kind of experience? How can the rhythm of the spectator's body be matched to the rhythm of Hitchcock's fast pace editing? And what form can this montage take and for what aesthetic and dramaturgical effects? To answer these questions, we propose the experiment of a montage that adapts in real time to the displacements of the body and the gaze of the spectator, engaging a dialectic between narrative rhythm and bodily rhythm. We propose new algorithmic tools to transport the audience into the story as originally planned by Hitchcock while at the same time respecting the bodily rhythm of the audience to guide the experience. In doing so, we seek to create a new form of relationship between the author of a narrative experience in virtual reality and the spectator who explores and activates the experience with his own body.

7.2 Supporting Perception of Spatiality in Dance in Augmented Reality

Participant: Mélina Skouras.

Dance in augmented reaity

This work, done in collaboration with the PhD student Manon Vialle, the researcher Sarah Fdili Alaoui (Ex-Situ Inria team) and the dancer Elisabeth Schwartz, presents how we co-designed with a connoisseur a system that visualizes a star-like ribbon joining at the solar plexus and animated it from motion capture data to perform Isadora Duncan’s dances. Additionally, the system visualizes the trace of the solar plexus and specific keyframes of the choreography as key poses placed in the 3D space. We display the visualization in a Hololens headset and provide features that allow to manipulate it in order to understand and learn Duncan’s qualities and choreographic style. Through a workshop with dancers, we ran a structured observation where we compared qualitatively how the dancers were able to perceive Duncan’s qualities and embody them using the system set according to two different conditions: displaying all the future keyframes or displaying a limited number of keyframes. We discuss the results of our workshop and the use of augmented reality in the studio for pedagogical purposes.

7.3 Complex Wrinkle Field Evolution

Participant: Mélina Skouras.

Wrinkle field

This work results of a collaboration with the PhD student Zhen Chen (UT Austin) and the researchers Etienne Vouga (UT Austin) and Danny Kaufman (Adobe research). It proposes a new approach for representing wrinkles, designed to cap- ture complex and detailed wrinkle behavior on coarse triangle meshes, called Complex Wrinkle Fields. Complex Wrinkle Fields consist of an almost- everywhere-unit complex-valued phase function over the surface; a fre- quency one-form; and an amplitude scalar, with a soft compatibility condition coupling the frequency and phase. We develop algorithms for interpolating between two such wrinkle fields, for visualizing them as displacements of a Loop-subdivided refinement of the base mesh, and for making smooth local edits to the wrinkle amplitude, frequency, and/or orientation. These algorithms make it possible, for the first time, to create and edit animations of wrinkles on triangle meshes that are smooth in space, evolve smoothly through time, include singularities along with their complex interactions, and that represent frequencies far finer than the surface resolution.

7.4 3D auxetic meso-structures for turbine blade

Participant: Stefanie Hahmann.

3D auxetic meso-structures filling the kernel of a turbine blade.

In the framework of the FET Open European Project ADAM2 we are working on producing geometric meso-structures with specific mechanical properties, that can be used for the conception of lightweight object. As a central testcase for which all the ADAM2 partners expertise is required, the conception of a turbine blade was addressed. Together with the Technion group, we were responsible of designing the geometry of the meso-structures, while our partners in applied mathematics at TU Wien and EPFL were focusing on the analysis of the mechanical properties, our partners at BCAM and UPV were fabricating the prototypes with 5-axis CNC machining and metal laser power bed fusion, and UPV and Trimek were doing experimental measurements on the fabricated prototypes. We are currently writing a common publication with all partners, describing the work on the turbine blade conception.

8.1 International research visitors

8.2 European initiatives

8.3 National initiatives

9.1 Promoting scientific activities

9.2 Teaching - Supervision - Juries

9.3 Popularization

10.1 Major publications

• 1 articleZ.Zhen Chen, H.-Y.Hsiao-Yu Chen, D. M.Danny M Kaufman, M.Mélina Skouras and E.Etienne Vouga. Fine Wrinkling on Coarsely Meshed Thin Shells.ACM Transactions on Graphics405August 2021, 1-32HALDOI
• 2 articleA.Amélie Fondevilla, D.Damien Rohmer, S.Stefanie Hahmann, A.Adrien Bousseau and M.-P.Marie-Paule Cani. Fashion Transfer: Dressing 3D Characters from Stylized Fashion Sketches.Computer Graphics Forum4062021, 466-483HALDOI
• 3 inproceedingsM.Maxime Garcia and R.Rémi Ronfard. Recognition of Laban Effort Qualities from Hand Motion.MOCO'20 - 7th International Conference on Movement and ComputingArticle No.: 8Jersey City/ Virtual, United StatesJuly 2020, 1-8HALDOI
• 4 articleY.Youna Le Vaou, J.-C.Jean-Claude Léon, S.Stefanie Hahmann, S.Stéphane Masfrand and M.Matthieu Mika. As-Stiff-As-Needed Surface Deformation Combining ARAP Energy with an Anisotropic Material.Computer-Aided Design121April 2020, 1-15HALDOI
• 5 articleR.Rémi Ronfard. Film Directing for Computer Games and Animation.Computer Graphics Forum402May 2021, 713-730HALDOI

10.2 Publications of the year

10.3 Other

10.4 Cited publications

• 15 articleA.Adela Barbulescu, R.Rémi Ronfard and G.Gérard Bailly. A Generative Audio-Visual Prosodic Model for Virtual Actors.IEEE Computer Graphics and Applications376November 2017, 40-51HALDOIback to text
• 16 articleH.Herbert Clarck. Depicting as a method of communication.Psychological Review1232016, 324–347back to text
• 17 articleJ. E.James E. Cutting, J. E.Jordan E. DeLong and C. E.Christine E. Nothelfer. Attention and the Evolution of Hollywood Film.Psychological Science2132010, 432-439back to text
• 18 inproceedingsM.Markus Eger and K. W.Kory W Mathewson. dAIrector: Automatic Story Beat Generation through Knowledge Synthesis.Proceedings of the Joint Workshop on Intelligent Narrative Technologies and Workshop on Intelligent Cinematography and Editing2018back to text
• 19 inproceedingsQ.Quentin Galvane, M.Marc Christie, C.Christophe Lino and R.Rémi Ronfard. Camera-on-rails: Automated Computation of Constrained Camera Paths.ACM SIGGRAPH Conference on Motion in GamesParis, FranceACMNovember 2015, 151-157HALDOIback to text
• 20 inproceedingsQ.Quentin Galvane, R.Rémi Ronfard, C.Christophe Lino and M.Marc Christie. Continuity Editing for 3D Animation.AAAI Conference on Artificial IntelligenceAustin, Texas, United StatesAAAI PressJanuary 2015, 753-761HALback to text
• 21 inproceedingsV.Vineet Gandhi, R.Rémi Ronfard and M.Michael Gleicher. Multi-Clip Video Editing from a Single Viewpoint.European Conference on Visual Media ProductionLondon, United KingdomACMNovember 2014back to text
• 22 inproceedingsM.Maxime Garcia, R.Rémi Ronfard and M.-P.Marie-Paule Cani. Spatial Motion Doodles: Sketching Animation in VR Using Hand Gestures and Laban Motion Analysis.Motion, Interaction and GamesOctober 2019HALDOIback to text
• 23 inproceedingsD.David Gochfeld, C.Corinne Brenner, K.Kris Layng, S.Sebastian Herscher, C.Connor DeFanti, M.Marta Olko, D.David Shinn, S.Stephanie Riggs, C.Clara Fernández-Vara and K.Ken Perlin. Holojam in Wonderland: Immersive Mixed Reality Theater.ACM SIGGRAPH 2018 Art GallerySIGGRAPH '182018back to text
• 24 inproceedingsB.Barbara Hayes-Roth and R. V.Robert Van Gent. Improvisational puppets, actors, and avatars.Proc Comp Game Dev Conf1996back to text
• 25 inproceedingsK.Kris Layng, K.Ken Perlin, S.Sebastian Herscher, C.Corinne Brenner and T.Thomas Meduri. Cave: Making Collective Virtual Narrative.ACM SIGGRAPH 2019 Art GallerySIGGRAPH '192019back to text
• 26 articleZ.Zhaoliang Lun, E.Evangelos Kalogerakis, R.Rui Wang and A.Alla Sheffer. Functionality Preserving Shape Style Transfer.ACM Transactions on Graphics3562016back to text
• 27 articleB.Brian Magerko, W.Waleed Manzoul, M.Mark Riedl, A.Allan Baumer, D.Daniel Fuller, K.Kurt Luther and C.Celia Pearce. An empirical study of cognition and theatrical improvisation.Creativity and Cognition2009back to text
• 28 bookJ. H.Janet H. Murray. Hamlet on the Holodeck, The Future of Narrative in Cyberspace, Updated Edition.MIT Press2017back to text
• 29 inproceedingsO.Olivier Palombi, G.Guillaume Bousquet, D.David Jospin, S.Sahar Hassan, L.Lionel Revéret and F.François Faure. My Corporis Fabrica: A Unified Ontological, Geometrical and Mechanical View of Human Anatomy.Proceedings of the 2009 International Conference on Modelling the Physiological Human3DPH'092009, 209--219back to text
• 30 inproceedingsR.Rémi Ronfard, V.Vineet Gandhi, L.Laurent Boiron and V. A.Vaishnavi Ameya Murukutla. The Prose Storyboard Language: A Tool for Annotating and Directing Movies.WICED 2022 - 10th Workshop on Intelligent Cinematography and EditingReims, FranceApril 2022, 1-16HALback to text
• 31 inproceedingsC.C. Thomas and A.A. Kovashka. Seeing Behind the Camera: Identifying the Authorship of a Photograph.2016 IEEE Conference on Computer Vision and Pattern Recognition (CVPR)2016, 3494-3502back to text
• 32 articleF.Federico Ulliana, J.-C.Jean-Claude Léon, O.Olivier Palombi, M.-C.Marie-Christine Rousset and F.François Faure. Combining 3D Models and Functions through Ontologies to Describe Man-made Products and Virtual Humans: Toward a Common Framework.Computer-Aided Design and Applications1222015, 166-180HALDOIback to text
• 33 articleM. S.Mei Si et al.. Thespian : An architecture for interactive pedagogical drama.Artificial Intelligence in Education1252005, 595–602back to text