Outside-in

For believable character animation, skin deformation should communicate important deformation effects due to underlying muscle movement. Anatomical models that capture these effects are typically constructed from the in-side out. Internal tissue is modeled by hand and a surface skin is attached to, or generated from, the internal structure. This paper presents an outside–in approach to anatomical modeling, in which we generate musculature from a predefined structure, which we conform to an artist–sculpted skin surface. Motivated by interactive appli-cations, we attach the musculature to an existing control skeleton and apply a novel geometric deformation model to deform the skin surface to capture important muscle motion effects. Musculoskeletal structure can be stored as a template and applied to new character models. We illustrate the methodology, as integrated into a commercial character animation system, with examples driven by both keyframe animation and recorded motion data

Automatic Cage Construction for Retargeted Muscle Fitting

The animation of realistic characters necessitates the construction of complicated anatomical structures such as muscles, which allow subtle shape variation of the character's outer surface to be displayed believably. Unfortunately despite numerous efforts, the modelling of muscle structures is still left for an animator who has to painstakingly build up piece by piece, making it a very tedious process. What is even more frustrating is the animator has to build the same muscle structure for every new character. We propose a muscle retargeting technique to help an animator to automatically construct a muscle structure by reusing an already built and tested model (the template model). Our method defines a spatial transfer between the template model and a new model based on the skin surface and the rigging structure. To ensure that the retargeted muscle is tightly packed inside a new character, we define a novel spatial optimization based on spherical parameterization. Our method requires no manual input, meaning that an animator does not require anatomical knowledge to create realistic accurate musculature models

Cyclic animation using Partial differential Equations

YesThis work presents an efficient and fast method for achieving cyclic animation using Partial Differential Equations (PDEs). The boundary-value nature associ- ated with elliptic PDEs offers a fast analytic solution technique for setting up a framework for this type of animation. The surface of a given character is thus cre- ated from a set of pre-determined curves, which are used as boundary conditions so that a number of PDEs can be solved. Two different approaches to cyclic ani- mation are presented here. The first consists of using attaching the set of curves to a skeletal system hold- ing the animation for cyclic motions linked to a set mathematical expressions, the second one exploits the spine associated with the analytic solution of the PDE as a driving mechanism to achieve cyclic animation, which is also manipulated mathematically. The first of these approaches is implemented within a framework related to cyclic motions inherent to human-like char- acters, whereas the spine-based approach is focused on modelling the undulatory movement observed in fish when swimming. The proposed method is fast and ac- curate. Additionally, the animation can be either used in the PDE-based surface representation of the model or transferred to the original mesh model by means of a point to point map. Thus, the user is offered with the choice of using either of these two animation repre- sentations of the same object, the selection depends on the computing resources such as storage and memory capacity associated with each particular application

Atlas-Based Character Skinning with Automatic Mesh Decomposition

Skinning is the most tedious part in the character animation process. Using standard methods, joint weights must be attached to each vertex of the character's mesh, which is often time-consuming if an accurate animation is required. We propose a new modeling of the skinning process, inspired by the notion of atlas of charts. Starting from the character's animation skeleton, we first automatically decompose the mesh into anatomically meaningful overlapping regions. Regions are then blended in their overlapping parts using continuous transition functions. This leads to a simple yet efficient skinning process for which the weights are automatically defined and do not depend on the Euclidean distance but on the distance on the surface.Le skinning est l'étape la plus fastidieuse du processus d'animation d'un personnage. Dans les méthodes classiques, un poids associé à chaque articulation doit être attaché à chaque sommet du maillage du personnage, ce qui est souvent très coûteux en temps lorsqu'une animation précise est exigée. Nous proposons une nouvelle modélisation du processus de skinning, s'inspirant de la notion d'atlas de cartes. A partir du squelette d'animation du personnage, nous décomposons d'abord automatiquement le maillage en régions anatomiquement significatives et qui se chevauchent. Ces régions sont ensuite fusionnées dans leurs zones de chevauchement grˆace à l'utilisation de fonctions de transition continues. Ceci conduit à un processus de skinning simple mais néanmoins efficace, pour lequel les poids sont automatiquement définis et ne dépendent pas de la distance euclidienne entre sommets, mais de la distance sur la surface

Hands as characters: designing for a large scale pipeline using limited characteristics

This thesis concentrates on hands and their production as concerns a larger-scale pipeline with multiple secondary or tertiary characters. It establishes a platform from which many unique hands can be produced from a single, rigged hand. Emphasis is given to automating a large amount of the rigging and sculpting processes through use of high and low-level user interfaces so users of varying skill can use this thesis effectively. Systems for sculpting the hand and animating the hand are created for their own specific purposes and linked together through the interface to create a tool for modeling a new hand from an existing mesh, having the new hand automatically rigged for animation and ready to use with only minor adjustments by the user. A system is developed conclusively that allows for the efficient mass production of tertiary character assets. Unique hands are quickly and correctly created with the ability to connect them to digital characters. This method can be applied not only to hands, but other parts of characters as well. Eventually full secondary or tertiary characters can be created using this method of production

Footwear bio-modelling: An industrial approach

There is a growing need within the footwear sector to customise the design of the last from which a specific footwear style is to be produced. This customisation is necessary for user comfort and health reasons, as the user needs to wear a suitable shoe. For this purpose, a relationship must be established between the user foot and the last with which the style will be made; up until now, no model has existed that integrates both elements. On the one hand, traditional customised footwear manufacturing techniques are based on purely artisanal procedures which make the process arduous and complex; on the other hand, geometric models proposed by different authors present the impossibility of implementing them in an industrial environment with limited resources for the acquisition of morphometric and structural data for the foot, apart from the fact that they do not prove to be sufficiently accurate given the non-similarity of the foot and last. In this paper, two interrelated geometric models are defined, the first, a bio-deformable foot model and the second, a deformable last model. The experiments completed show the goodness of the model, with it obtaining satisfactory results in terms of comfort, efficiency and precision, which make it viable for use in the sector

Modelli deformabili della mano a partire da dati acquisiti tramite laser scanner

Questa tesina mostra come sia possibile realizzare il modello tridimensionale di una mano reale utilizzando uno scanner 3D economico. Lo scopo di questo lavoro è di creare un database contenente le mani di differenti persone a cui è associato uno scheletro. Attraverso l’uso di software specializzato è stato creato uno scheletro per ogni modello. Tali modelli verranno poi utilizzati per lo sviluppo di una tecnica di riconoscimento della mano da una camera 3D. Sono stati realizzati dei video-tutorial reperibili online che descrivono i procedimenti seguit

Senescence: An Aging based Character Simulation Framework

The \u27Senescence\u27 framework is a character simulation plug-in for Maya that can be used for rigging and skinning muscle deformer based humanoid characters with support for aging. The framework was developed using Python, Maya Embedded Language and PyQt. The main targeted users for this framework are the Character Technical Directors, Technical Artists, Riggers and Animators from the production pipeline of Visual Effects Studios. The characters that were simulated using \u27Senescence\u27 were studied using a survey to understand how well the intended age was perceived by the audience. The results of the survey could not reject one of our null hypotheses which means that the difference in the simulated age groups of the character is not perceived well by the participants. But, there is a difference in the perception of simulated age in the character between an Animator and a Non-Animator. Therefore, the difference in the simulated character\u27s age was perceived by an untrained audience, but the audience was unable to relate it to a specific age group

"Studio e implementazione di un algoritmo per lo skinning automatico di mesh poligonali deformabili"

L’animazione tridimensionale è un argomento di grande interesse in svariati ambiti, che vanno dal puro intrattenimento a più serie simulazioni. Esistono numerosissime tecniche di animazione che bilanciano in modo diverso prestazioni, qualità dei risultati, semplicità dell’approccio e possibilità di riutilizzo. In questo scenario trova uno spazio tutto suo l’animazione di figure umanoidi, i cosiddetti Virtual Humans (VHs). Da circa 50 anni la ricerca ha prodotto una gran quantità di metodi per trattare VHs, adatti alle più diverse esigenze e occupandosi di riprodurre le molteplici sfaccettature del movimento umano. Tra i molti campi di applicazione dell’animazione umana, citiamo alcuni esempi: la simulazione per l’addestramento nell’eseguire operazioni pericolose, difficili o comunque che comporterebbero alti costi; l’analisi dell’interazione umana con oggetti ed ambienti; la creazione di attori virtuali per l’entertainment; lo studio di nuovi metodi di interazione uomo-macchina; le ricostruzioni di attività umane a scopo didattico o per riprodurre e studiare le dinamiche di eventi. Tra i metodi per modellare il movimento di figure umane, uno dei paradigmi più diffusi si basa sull’utilizzo di due elementi: il primo è un’approssimazione dello scheletro (skeleton) che viene usato per descrivere le animazioni in modo indipendente dalla figura da animare, così da poter essere riutilizzabile con diversi modelli; il secondo è il modello da animare, che viene visto come una superficie detta pelle (skin), la quale si modifica seguendo lo skeleton. Un approccio per far si che la skin si deformi secondo le ossa (bones) dello skeleton è chiamato skinning. L’algoritmo più diffuso per effettuare lo skinning nel campo delle applicazioni real-time è noto sotto il nome di Linear Blend Skinning (LBS). Tale approccio consiste nell’associare ad ogni vertice della skin un peso che varia tra 0 e 1 per ogni bones, di modo che più il bone ha influenza sul vertice più tale peso è vicino a 1. I pesi vengono poi usati in un blend lineare di trasformazioni rigide per deformare la skin. Il settaggio dei pesi per ogni vertice avviene generalmente in modo manuale tramite l’ausilio di appositi tool, integrati in strumenti di modellazione. Quest’operazione comporta comunque un certo sforzo da parte del modellatore. Inoltre in certi applicativi si preferirebbe che la determinazione dei pesi avvenisse in modo totalmente automatico e con buoni risultati visivi, senza la necessità di intervento da parte di un modellatore esperto. In questa tesi si analizzano i metodi più noti per il calcolo automatico dei pesi da utilizzare assieme all’LBS, di modo da ottenere una distribuzione dei pesi il più realistica possibile

Emprovador virtual de roba

L'objectiu principal d'aquest projecte és obtenir vídeos d'animacions d'avatars semblants a l'usuari, que estiguin vestits i que reprodueixin els mateixos moviments que l'usuari