Abstract Enabling animators to smoothly transform between animated meshes of differing topologies is a long‐standing problem in geometric modelling and computer animation. In this paper, we propose a new hybrid approach built upon the advantages of scalar field‐based models (often called implicit surfaces) which can easily change their topology by changing their defining scalar field. Given two meshes, animated by their rigging‐skeletons, we associate each mesh with its own approximating implicit surface. This implicit surface moves synchronously with the mesh. The shape‐metamorphosis process is performed in several steps: first, we collapse the two meshes to their corresponding approximating implicit surfaces, then we transform between the two implicit surfaces and finally we inverse transition from the resulting metamorphosed implicit surface to the target mesh. The examples presented in this paper demonstrating the results of the proposed technique were implemented using an in‐house plug‐in for Maya™.

Polygonal models are widely used in computer animation. Static polygonal models are commonly animated using an underlying skeleton controlling the deformation of the mesh. This technique, known as skeletal animation, allows the artist to produce complex animation sequences in a relatively easy way. However, performing complex transitions between arbitrary animated meshes remains a challenging problem. There is a set of established techniques to perform metamorphosis (3D morphing) between static 3D meshes [Lazarus and Verroust 1998], but most of these can not be easily applied to animated meshes. The approach presented in this poster allows us to produce with great ease metamorphosing transitions between animated meshes of arbitrary topology using polygonal-functional hybrids [Kravtsov et al. 2010a]. Our technique uses the meshes of the objects as well as their skeleton animations. As a result we are able to generate metamorphosis animations of time-varying meshes of arbitrary topologies in near real-time.

Most of the existing methods of metamorphosis are based on the interpolation schemes, space-time blending is a geometric operation of bounded blending performed in the higher-dimensional space. It provides transformations between shapes of different topology without necessarily establishing their alignment or correspondence. The original formulation of space-time blending had several problems: fast uncontrolled transition between shapes within the given time interval, generation of disconnected components, and lack of intuitive user control over the transformation process. We improve the original technique to provide the user with a set of more intuitive controls. The problem of the fast transition between the shapes is solved by the introduction of additional controllable affine transformations applied to initial objects in space-time. The approach is further extended with the introduction of an additional non-linear deformation operation. The proposed techniques have been implemented and tested within an industrial computer animation system. We have also implemented our method on the GPU, so that it can be employed in real-time applications.

Abstract In this paper, we address shape modelling problems, encountered in computer animation and computer games development that are difficult to solve just using polygonal meshes. Our approach is based on a hybrid‐modelling concept that combines polygonal meshes with implicit surfaces. A hybrid model consists of an animated polygonal mesh and an approximation of this mesh by a convolution surface stand‐in that is embedded within it or is attached to it. The motions of both objects are synchronised using a rigging skeleton. We model the interaction between an animated mesh object and a viscoelastic substance, which is normally represented in an implicit form. Our approach is aimed at achieving verisimilitude rather than physically based simulation. The adhesive behaviour of the viscous object is modelled using geometric blending operations on the corresponding implicit surfaces. Another application of this approach is the creation of metamorphosing implicit surface parts that are attached to an animated mesh. A prototype implementation of the proposed approach and several examples of modelling and animation with near real‐time preview times are presented.

Extensions to interactive digital TV (iDTV) platforms enabling interaction of iDTV applications with devices in the home network may create additional value for consumers. Recently, CableLabs has issued a specification for an OCAP Home Networking Extension that describes Application Programming Interfaces (APIs) to enable sharing of content between OCAP compliant devices in a home network. The next logical step is to expand the capabilities of this home networking extension to enable iDTV applications to interact with other types of devices connected to the home network. In this paper we propose a framework, called the DTV Home Networking Framework (DTV-HNF), that provides mechanisms for interaction with devices in the home network in a manner that is independent of device functionality and underlying network technology. The approach is illustrated by implementation of prototypes demonstrating interaction of iDTV applications with devices connected using OSGi and UPnP home networking frameworks.