Rigging Realistic Skin Deformation with Muscle Systems

Realistic skin deformation is one of the major criteria for creating believable, dig- itally enhanced characters. Muscle simulation is one of the more popular techniques used in filmmaking. It helps bring a sense of realism to the character by adding subtle, secondary motion to the skin. Small features like these make the character appear more lifelike. This thesis focuses on the generation of a character rig and implementation of a digital muscle system for a tiger. The rig is built and animated in Maya and the Maya Muscle tool was used to create the muscle system. The muscle deformations are compared to the standard smooth skinning method in a walk and run animation

Shape manipulation using physically based wire deformations

This paper develops an efficient, physically based shape manipulation technique. It defines a 3D model with profile curves, and uses spine curves generated from the profile curves to control the motion and global shape of 3D models. Profile and spine curves are changed into profile and spine wires by specifying proper material and geometric properties together with external forces. The underlying physics is introduced to deform profile and spine wires through the closed form solution to ordinary differential equations for axial and bending deformations. With the proposed approach, global shape changes are achieved through manipulating spine wires, and local surface details are created by deforming profile wires. A number of examples are presented to demonstrate the applications of our proposed approach in shape manipulation

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

Procedural Generation of 2D Creatures

Käesoleva bakalaureusetöö raames arendati 2D olendite genereerimise süsteem ning selle süsteemi implementatsioon programmeerimiskeeles JavaScript. Süsteem tekitab mitmekesiseid olendeid ning nendega seotud andmed, sealhulgas skelett, geomeetria ja tekstuur. Bakalaureusetöö sisaldab süsteemi kirjeldust. Süsteemi iga sammu kohta on välja toodud tähtsamad põhimõtted ning seletatud mõned implementatsiooni üksikasjad.Töös analüüsitakse süsteemi tervikuna ning selle implementatsiooni. Tuuakse välja süsteemi probleemid ning nõrgad kohad ja mõõdetakse implementatsiooni jõudlust. Töö lõpus tuuakse välja süsteemi kasutusvõimalused ja võimalused selle edasi arendamiseks.The purpose of this thesis is the development of a system capable of generating a large variety of 2D creatures and their associated data, such as skeletons, meshes and textures. A JavaScript implementation of the system was developed for this thesis. This thesis contains a description of the developed system and a description of each step of the generation process and its principles with some additional notes about the specifics of the implementation.The creature generation system as a whole and its implementation are analysed and their advantages and drawbacks brought out. The performance of the implementation is also tested. Several possible improvements are proposed at the end of the thesis, as well as possible uses

Unwind: Interactive Fish Straightening

The ScanAllFish project is a large-scale effort to scan all the world's 33,100 known species of fishes. It has already generated thousands of volumetric CT scans of fish species which are available on open access platforms such as the Open Science Framework. To achieve a scanning rate required for a project of this magnitude, many specimens are grouped together into a single tube and scanned all at once. The resulting data contain many fish which are often bent and twisted to fit into the scanner. Our system, Unwind, is a novel interactive visualization and processing tool which extracts, unbends, and untwists volumetric images of fish with minimal user interaction. Our approach enables scientists to interactively unwarp these volumes to remove the undesired torque and bending using a piecewise-linear skeleton extracted by averaging isosurfaces of a harmonic function connecting the head and tail of each fish. The result is a volumetric dataset of a individual, straight fish in a canonical pose defined by the marine biologist expert user. We have developed Unwind in collaboration with a team of marine biologists: Our system has been deployed in their labs, and is presently being used for dataset construction, biomechanical analysis, and the generation of figures for scientific publication

An Automated Build System for Articulated Characters

Rigging is the process of designing and implementing the manipulation architecture for an animated three-dimensional character. Rigs that give the animator the most control tend to be the most difficult to set up and maintain. Due to the linear nature of some elements of rigging, the more complicated a rig, the more time-intensive--and therefore more expensive--to achieve a high quality rig. A solution to complex rig iterability is to automate as much of the process as possible. The topic of this thesis is a framework for modular rigging automation, with a focus on quick and efficient rig iteration. A rigger is able to design a rig from predefined module elements (rig blocks) or quickly script new blocks. A rig is deconstructed into these elemental blocks and merged into a single rig script to regenerate the rig and attach a character\u27s geometry

Modelling and Animation using Partial Differential Equations. Geometric modelling and computer animation of virtual characters using elliptic partial differential equations.

This work addresses various applications pertaining to the design, modelling and animation of parametric surfaces using elliptic Partial Differential Equations (PDE) which are produced via the PDE method. Compared with traditional surface generation techniques, the PDE method is an effective technique that can represent complex three-dimensional (3D) geometries in terms of a relatively small set of parameters. A PDE-based surface can be produced from a set of pre-configured curves that are used as the boundary conditions to solve a number of PDE. An important advantage of using this method is that most of the information required to define a surface is contained at its boundary. Thus, complex surfaces can be computed using only a small set of design parameters. In order to exploit the advantages of this methodology various applications were developed that vary from the interactive design of aircraft configurations to the animation of facial expressions in a computer-human interaction system that utilizes an artificial intelligence (AI) bot for real time conversation. Additional applications of generating cyclic motions for PDE based human character integrated in a Computer-Aided Design (CAD) package as well as developing techniques to describe a given mesh geometry by a set of boundary conditions, required to evaluate the PDE method, are presented. Each methodology presents a novel approach for interacting with parametric surfaces obtained by the PDE method. This is due to the several advantages this surface generation technique has to offer. Additionally, each application developed in this thesis focuses on a specific target that delivers efficiently various operations in the design, modelling and animation of such surfaces.The project files will not be available online

Generalized partial differential equations for interactive design

This paper presents a method for interactive design by means of extending the PDE based approach for surface generation. The governing partial differential equation is generalized to arbitrary order allowing complex shapes to be designed as single patch PDE surfaces. Using this technique a designer has the flexibility of creating and manipulating the geometry of shape that satisfying an arbitrary set of boundary conditions. Both the boundary conditions which are defined as curves in 3-space and the spine of the corresponding PDE are utilized as interactive design tools for creating and manipulating geometry intuitively. In order to facilitate interactive design in real time, a compact analytic solution for the chosen arbitrary order PDE is formulated. This solution scheme even in the case of general boundary conditions satisfies exactly the boundary conditions where the resulting surface has an closed form representation allowing real time shape manipulation. In order to enable users to appreciate the powerful shape design and manipulation capability of the method, we present a set of practical examples