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 13 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 28. 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 PhD thesis

Ameya Murukutla defended her PhD thesis on "Text-to-movie authoring of anatomy lessons" on December 7, 2021.

The jury was composed of Marie-Christine Rousset (UGA), Philippe Joly (IRIT, Univ. Toulouse), Pierre-Antoine Champin (LIRIS, Univ. Lyon, ERCIM), Nady Hoyek (Univ. Lyon) and Marc Braun (doyen de la faculté de médecine de l’Université de Lorraine).

6.2 Awards

Mélina Skouras received the Young Researcher Award 2021 from Shape Modeling International.

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7.1 Film directing for Computer Games and Animation

Participants: Rémi Ronfard.

In this comprehensive survey, we present a historical and up-to-date summary of research in algorithmic film directing, and identify promising avenues and hot topics for future research.

The survey was presented as a state-of-the-art report (STAR) during the online Eurographics conference in May 2021, and constitutes the first chapter of the final report for the Montage Spatial joint project between ANIMA and ENSADLAB.

7.2 Fashion Transfer: Dressing 3D Characters from Stylized Fashion Sketches

Participant: Stefanie Hahmann.

Side by side fashion drawings and corresponding rendered 3D models.

An intuitive way to facilitate 3D creation is to use sketches, because everyone knows how to draw. However, reconstructing a 3D digital object from a drawing is a complex challenge that sketch-based modeling methods have been trying to address for the last decade. Indeed, a 2D image of an object can represent an infinity of 3D objects, since the depth is unknown. It is common to make assumptions about the object or to formulate geometrical constraints to restrict the space of solutions. Our novel approach is to take advantage of developable surfaces, not only for reconstruction from a single image of the object but also to allow an extension to fashion designs. Built on the differential geometry properties of developable surfaces, we have developed a sketch-based modeling system for stylized fashion sketches 6. This method not only preserves the style when reconstructing but also when transferring to characters with different morphology. This work is the result of a collaboration with Adrien Bousseau (GraphDeco INRIA) and Damien Rohmer, Marie-Paule Cani (LIX Ecole Polytechnique).

7.3 Fine Wrinkling on Coarsely-Meshed Thin Shells

Participant: Melina Skouras.

From left to right: base mesh, elastic energy, and wrinkle patterns.

In this work, we propose a new model and algorithm to capture the high-definition statics of thin shells via coarse meshes 5. This model predicts global, fine-scale wrinkling at frequencies much higher than the resolution of the coarse mesh; moreover, it is grounded in the geometric analysis of elasticity, and does not require manual guidance, a corpus of training examples, nor tuning of ad-hoc parameters. We first approximate the coarse shape of the shell using tension field theory, in which material forces do not resist compression. We then augment this base mesh with wrinkles, parameterized by an amplitude and phase field that we solve for over the base mesh, which together characterize the geometry of the wrinkles. We validate our approach against both physical experiments and numerical simulations, and show that our algorithm produces wrinkles qualitatively similar to those predicted by traditional shell solvers requiring orders of magnitude more degrees of freedom. This work is the result of a collaboration with Etienne Vouga's group (University of Texas at Austin) and Danny Kaufman (Adobe Research).

7.4 Geometric construction of auxetic metamaterials

Participant: Stefanie Hahmann.

Six views of the metamaterial.

Recent advances in digital manufacturing, where computational design, materials science and engineering meet, offer whole new perspectives for tailoring mechanical properties and fabrication of new meta-materials with applications as diverse as product design, architecture, engineering and art. A meta-material is a material whose microstructure can be controlled to achieve the desired macroscopic deformation behavior.

We focussed on a category of metamaterials called auxetic structures, or auxetic networks. Auxetic materials are characterized by a negative Poisson's ratio. They do not behave like usual materials, because when they are stretched in one direction, they expand in the perpendicular direction.Whereas regular auxetic networks are well studied, our focus is on disordered auxetic networks. In particular, we are exploring geometrical strategies to generate 2-dimensional random auxetic porous meta-materials. Starting from a dense irregular network, we seek to reduce the Poisson's ratio, by pruning bonds (edges) based solely on geometric criteria. To this end, we first deduce some prominent geometric features from regular auxetic networks and then introduce a strategy combining a pure geometric pruning algorithm followed by a physics-based testing phase to determine the resulting Poisson's ratio of our networks 4. We provide numerical results and statistical validation. We also show physical tests with both laser-cut rubber networks and 3D-printed networks showing auxetic behaviour, see Figure.

7.5 Feature Lines Modification Based on As-Stiff-As-Needed Surface Deformation

Participant: Stefanie Hahmann.

Three views of a car model.

Shape creation for the automotive industry can be thought of as exploring the "mental shape space" of designers. To improve communication between designers during a project review in an immersive environment, we introduced a new physics-based method to intuitively deform manufactured shapes. Standard methods such as ARAP shape deformation produce overly organic shapes, inappropriate in our context. With the goal of being able to control the material stiffness and prevent undesirable organic effects, we first introduced in 2020 virtual anisotropic materials for shape, associated with membrane-like structural behavior 2. We then developed in 2021 a deformation method guided by shape features 7 which gives the user a powerful tool for exploring a new shape space. The CIFRE thesis of Youna le Vaou co-supervised with JC Léon was a fruitful collaboration with the Virtual Reality center of PSA (S. Masfrand and M. Mika).

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8.1 European initiatives

8.2 National initiatives

8.3 Regional initiatives

9.1 Promoting scientific activities

9.2 Teaching - Supervision - Juries

10.1 Major publications

• 1 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, 1-8
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• 2 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, 1-15
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• 3 articleR.Rémi Ronfard and J.Julie Valéro. KinoAI and the audiovisual notebook : a plural solution for rehearsal studies.European Journal of Theatre and Performance2June 2020, 334-375
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10.2 Publications of the year

10.3 Cited publications

• 11 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, 40-51
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• 12 inproceedingsG. I.G Isla Borrell, J.Julie Valero and R.Rémi Ronfard. Réalité augmentée sur scène.Journées d'Informatique ThéâtralePerformance Lab, Univ. Grenoble AlpesGrenoble, FranceFebruary 2020
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• 13 articleH.Herbert Clarck. Depicting as a method of communication.Psychological Review1232016, 324–347
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• 14 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, 432-439
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• 15 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 Editing2018
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• 16 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, 151-157
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• 17 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, 753-761
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• 18 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 2014
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• 19 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 2019
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• 20 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 '182018
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• 21 inproceedingsB.Barbara Hayes-Roth and R. V.Robert Van Gent. Improvisational puppets, actors, and avatars.Proc Comp Game Dev Conf1996
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• 22 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 '192019
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• 23 articleZ.Zhaoliang Lun, E.Evangelos Kalogerakis, R.Rui Wang and A.Alla Sheffer. Functionality Preserving Shape Style Transfer.ACM Transactions on Graphics3562016
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• 24 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 Cognition2009
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• 25 bookJ. H.Janet H. Murray. Hamlet on the Holodeck, The Future of Narrative in Cyberspace, Updated Edition.MIT Press2017
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• 26 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--219
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• 27 inproceedingsJ.Jimmy Patouillard, J.Julie Valero and R.Rémi Ronfard. Etude des répétitions 2.0 : KINOAI, logiciel web.Journées d'Informatique ThéâtralePerformance Lab, Univ. Grenoble AlpesGrenoble, FranceFebruary 2020
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• 28 articleR.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.CoRRarXiv:1508.07593v32019
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• 29 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, 3494-3502
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• 30 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, 166-180
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• 31 inproceedings J.Julie Valero and R.Rémi Ronfard. Pourquoi l'informatique théâtrale ? Journées d'Informatique Théâtrale Performance Lab, Univ. Grenoble Alpes Grenoble, France February 2020
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• 32 articleM. S.Mei Si et al.. Thespian : An architecture for interactive pedagogical drama.Artificial Intelligence in Education1252005, 595–602
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