A Sketching Interface for Garment Design

National audienceThe range of approaches used for clothing virtual characters is large: for incidental characters, the clothing may be no more than a texture map. For lead characters in feature films, full-fledged physical simulation of detailed cloth models may be used. And in the midrange, simple skinning techniques, combined with texture mapping, are common, providing some deformation of clothing as the character moves, but no physical realism. There are three problems one can associate with clothing virtual characters: the design of the clothes (tailoring), placing them on the character (dressing), and making them look physically correct (typically through simulation). The process of tailoring involves choosing the cloth and fitting it to the body, often making adjustments in the patterns of the cloth to adapt it to the particular person's body shape, and then sewing it. For virtual characters, clothing often has no "patterns" from which it is sewn, instead it is represented by a simple polygonal mesh that is constructed to fit the body. It's currently tedious to construct such meshes even without the issues of patterns and stitching. It's sometimes done by directly incorporating the cloth mesh into a character's geometric model, so that the character doesn't actually have legs, for instance, but just pants (see figure 1.1). In this case physical simulation is no longer a possibility, and when a character needs new clothes, it must be largely re-modeled. An alternative approach involves drawing pattern pieces for a garment and positioning them over the naked form of the character, defining stitching constraints, etc. This can be tedious, especially when the character is not important enough to merit this amount of effort; it also requires an understanding of how cloth fits over shapes, although the actual pattern-and-stitching information may not be relevant after the tailoring is completed (except in the rare case where the physical properties of the cloth -- was it cut on the bias? Does the cloth resist folding along one axis? -- are later used in a full-fledged physical simulation). Our approach combines tailoring and dressing into a single step to create a mesh that's suitable for later simulation or skinning approaches. The idea is to make it easy to generate simple garments that are adapted to an existing model. We believe that most people know better how to draw garments than the patterns which are needed to sew them. The aim of this work is thus to explore the use of a sketch-based interface for quickly constructing 3D virtual garments over a character model. This report describes simple solutions to the problems of shape generation and placement of the clothing. The resulting system is so easy to use that it takes only few minutes to create a simple garment

Sketching garments for virtual characters

International audienceWe present a method for simply and interactively creating basic garments for dressing virtual characters in applications like video games. The user draws an outline of the front or back of the garment, and the system makes reasonable geometric inferences about the overall shape of the garment (ignoring constraints arising from physics and from the material of the garment). Thus both the garment's shape and the way the character is wearing it are determined at once. We use the distance from the 2D garment silhouette to the character model to infer the variations of the distance between the remainder of the garment and the character in 3D. The garment surface is generated from the silhouette and border lines and this varying distance information, thanks to a data-structure that stores the distance field to the character's body. This method is integrated in an interactive system in which the user sketches the garment over the 3D model of the character. Our results show that the system can be used to create both standard clothes (skirts, shirts) and other garments that may be worn in a variety of ways (scarves, panchos)

A Sketching Interface for Garment Design

National audienceThe range of approaches used for clothing virtual characters is large: for incidental characters, the clothing may be no more than a texture map. For lead characters in feature films, full-fledged physical simulation of detailed cloth models may be used. And in the midrange, simple skinning techniques, combined with texture mapping, are common, providing some deformation of clothing as the character moves, but no physical realism. There are three problems one can associate with clothing virtual characters: the design of the clothes (tailoring), placing them on the character (dressing), and making them look physically correct (typically through simulation). The process of tailoring involves choosing the cloth and fitting it to the body, often making adjustments in the patterns of the cloth to adapt it to the particular person's body shape, and then sewing it. For virtual characters, clothing often has no "patterns" from which it is sewn, instead it is represented by a simple polygonal mesh that is constructed to fit the body. It's currently tedious to construct such meshes even without the issues of patterns and stitching. It's sometimes done by directly incorporating the cloth mesh into a character's geometric model, so that the character doesn't actually have legs, for instance, but just pants (see figure 1.1). In this case physical simulation is no longer a possibility, and when a character needs new clothes, it must be largely re-modeled. An alternative approach involves drawing pattern pieces for a garment and positioning them over the naked form of the character, defining stitching constraints, etc. This can be tedious, especially when the character is not important enough to merit this amount of effort; it also requires an understanding of how cloth fits over shapes, although the actual pattern-and-stitching information may not be relevant after the tailoring is completed (except in the rare case where the physical properties of the cloth -- was it cut on the bias? Does the cloth resist folding along one axis? -- are later used in a full-fledged physical simulation). Our approach combines tailoring and dressing into a single step to create a mesh that's suitable for later simulation or skinning approaches. The idea is to make it easy to generate simple garments that are adapted to an existing model. We believe that most people know better how to draw garments than the patterns which are needed to sew them. The aim of this work is thus to explore the use of a sketch-based interface for quickly constructing 3D virtual garments over a character model. This report describes simple solutions to the problems of shape generation and placement of the clothing. The resulting system is so easy to use that it takes only few minutes to create a simple garment

Regards croisés sur la gestion des archives administratives au sein des Écoles françaises d’Athènes et de Rome

Introduction Fortes de plus de cent quarante ans d’activités, les Écoles françaises d’Athènes (Efa) et de Rome (Efr) disposent aujourd’hui d’un riche patrimoine archivistique qui s’est constitué au cours d’une histoire institutionnelle relativement stable (Radet 1901 ; Étienne 1996 ; Valenti 2006 ; Gras 2010 ; Gras & Poncet 2013). La mise à disposition de ce patrimoine auprès des chercheurs est inscrite dans les missions statutaires des deux établissements. Les archives qui y sont produites s..

A Procedural Approach to Style for NPR Line Drawing from 3D models

This paper introduces a procedural approach to non-photorealistic line drawing from 3D models. The approach is inspired both by procedural shaders in classical rendering and by the power of procedural modeling. We propose a new image creation model where all operations are controlled procedurally. A view map describing all relevant support lines in the drawing is first created from the 3d model; a number of style modules operate on this map, by procedurally selecting and chaining lines before creating strokes and assigning drawing attributes. Two different levels of user control are provided, ranging from a low-level programming API to a parameterized building-block assembly mechanism. The resulting drawing system allows very flexible control of all elements of drawing style: first, different style modules can be applied to different types of lines in a view; second, stroke attributes are assigned procedurally and can be correlated at will with various scene or view properties. We illustrate the components of our system and show results of its application

Sketching garments for virtual characters

International audienceWe present a method for simply and interactively creating basic garments for dressing virtual characters in applications like video games. The user draws an outline of the front or back of the garment, and the system makes reasonable geometric inferences about the overall shape of the garment (ignoring constraints arising from physics and from the material of the garment). Thus both the garment's shape and the way the character is wearing it are determined at once. We use the distance from the 2D garment silhouette to the character model to infer the variations of the distance between the remainder of the garment and the character in 3D. The garment surface is generated from the silhouette and border lines and this varying distance information, thanks to a data-structure that stores the distance field to the character's body. This method is integrated in an interactive system in which the user sketches the garment over the 3D model of the character. Our results show that the system can be used to create both standard clothes (skirts, shirts) and other garments that may be worn in a variety of ways (scarves, panchos)

Wavelet radiance transport for interactive indirect lighting

viewpoint can be modified interactively. The precomputation time was 23 minutes. Global illumination is a complex all-frequency phenomenon including subtle effects caused by indirect lighting. Computing global illumination interactively for dynamic lighting conditions has many potential applications, notably in architecture, motion pictures and computer games. It remains a challenging issue, despite the considerable amount of research work devoted to finding efficient methods. This paper presents a novel method for fast computation of indirect lighting; combined with a separate calculation of direct lighting, we provide interactive global illumination for scenes with diffuse and glossy materials, and arbitrarily distributed point light sources. To achieve this goal, we introduce three new tools: a 4D wavelet basis for concise radiance expression, an efficient hierarchical pre-computation of the Global Transport Operator representing the entire propagation of radiance in the scene in a single operation, and a run-time projection of direct lighting on to our wavelet basis. The resulting technique allows unprecedented freedom in the interactive manipulation of lighting for static scenes. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realis

Programmable Style for NPR Line Drawing

International audienceThis paper introduces a programmable approach to non-photorealistic line drawing from 3D models, inspired by programmable shaders in traditional rendering. We propose a new image creation model where all operations are controlled through user-defined procedures. A view map describing all relevant support lines in the drawing and their topological arrangement is first created from the 3D model; a number of style modules operate on this map, by procedurally selecting, chaining or splitting lines, before creating strokes and assigning drawing attributes. The resulting drawing system permits flexible control of all elements of drawing style: first, different style modules can be applied to different types of lines in a view; second, the topology and geometry of strokes are entirely controlled from the programmable modules; and third, stroke attributes are assigned procedurally and can be correlated at will with various scene or view properties. Finally, we propose new density control strategies where strokes can be adapted or omitted to avoid visual clutter. We illustrate the components of our system and show how style modules successfully capture stylized visual characteristics that can be applied across a wide range of models

A sketch-based interface for clothing virtual characters

Special issue on sketch based modelingInternational audienceWe present a new method for interactively creating garments for dressing virtual characters. The user draws an outline of the front and back of the garment, and the system makes reasonable geometric inferences about the overall shape of the garment (ignoring constraints arising from physics). Both the garment's shape and the way the character is wearing it are determined at once. We use the distance from the 2D garment silhouette to the character model to infer the variations of the distance between the remainder of the garment and the character in 3D. The garment surface is generated from the silhouette and border lines and this varying distance information, using a distance field to the character's body. This method is integrated in an interactive system in which the user sketches the garment over the 3D model of the character. Our results show that the system can be used to create a broad range of clothes that may be worn in a variety of ways