Real Time Animation of Virtual Humans: A Trade-off Between Naturalness and Control

Virtual humans are employed in many interactive applications using 3D virtual environments, including (serious) games. The motion of such virtual humans should look realistic (or ‘natural’) and allow interaction with the surroundings and other (virtual) humans. Current animation techniques differ in the trade-off they offer between motion naturalness and the control that can be exerted over the motion. We show mechanisms to parametrize, combine (on different body parts) and concatenate motions generated by different animation techniques. We discuss several aspects of motion naturalness and show how it can be evaluated. We conclude by showing the promise of combinations of different animation paradigms to enhance both naturalness and control

Developing serious games for cultural heritage: a state-of-the-art review

Although the widespread use of gaming for leisure purposes has been well documented, the use of games to support cultural heritage purposes, such as historical teaching and learning, or for enhancing museum visits, has been less well considered. The state-of-the-art in serious game technology is identical to that of the state-of-the-art in entertainment games technology. As a result, the field of serious heritage games concerns itself with recent advances in computer games, real-time computer graphics, virtual and augmented reality and artificial intelligence. On the other hand, the main strengths of serious gaming applications may be generalised as being in the areas of communication, visual expression of information, collaboration mechanisms, interactivity and entertainment. In this report, we will focus on the state-of-the-art with respect to the theories, methods and technologies used in serious heritage games. We provide an overview of existing literature of relevance to the domain, discuss the strengths and weaknesses of the described methods and point out unsolved problems and challenges. In addition, several case studies illustrating the application of methods and technologies used in cultural heritage are presented

The Stretch-Engine: A Method for Creating Exaggeration in Animation Through Squash and Stretch

Animators exaggerate character motion to emphasize personality and actions. Exaggeration is expressed by pushing a character’s pose, changing the action’s timing, or by changing a character’s form. This last method, referred to as squash and stretch, creates the most noticeable change in exaggeration. However, without practice, squash and stretch can adversely affect the animation. This work introduces a method to create exaggeration in motion by focusing solely on squash and stretch to control changes in a character’s form. It does this by displaying a limbs' path of motion and altering the shape of that path to create a change in the limb’s form. This paper provides information on tools that exist to create animation and exaggeration, then discusses the functionality and effectiveness of these tools and how they influenced the design of the Stretch-Engine. The Stretch-Engine is a prototype tool developed to demonstrate this approach and is designed to be integrated into an existing animation software, Maya. The Stretch-Engine contains a bipedal-humanoid rig with controls necessary for animation and the ability to squash and stretch. It can be accessed through a user interface that allows the animator to control squash and stretch by changing the shape of generated paths of motion. This method is then evaluated by comparing animations of realistic motion to versions created with the Stretch-Engine. These stretched versions displayed exaggerated results for their realistic counterparts, creating similar effects to Looney Tunes animation. This method fits within the animator’s workflow and helps new artists visualize and control squash and stretch to create exaggeration

Serious Games in Cultural Heritage

Although the widespread use of gaming for leisure purposes has been well documented, the use of games to support cultural heritage purposes, such as historical teaching and learning, or for enhancing museum visits, has been less well considered. The state-of-the-art in serious game technology is identical to that of the state-of-the-art in entertainment games technology. As a result the field of serious heritage games concerns itself with recent advances in computer games, real-time computer graphics, virtual and augmented reality and artificial intelligence. On the other hand, the main strengths of serious gaming applications may be generalised as being in the areas of communication, visual expression of information, collaboration mechanisms, interactivity and entertainment. In this report, we will focus on the state-of-the-art with respect to the theories, methods and technologies used in serious heritage games. We provide an overview of existing literature of relevance to the domain, discuss the strengths and weaknesses of the described methods and point out unsolved problems and challenges. In addition, several case studies illustrating the application of methods and technologies used in cultural heritage are presented

Comparing and Evaluating Real Time Character Engines for Virtual Environments

As animated characters increasingly become vital parts of virtual environments, then the engines that drive these characters increasingly become vital parts of virtual environment software. This paper gives an overview of the state of the art in character engines, and proposes a taxonomy of the features that are commonly found in them. This taxonomy can be used as a tool for comparison and evaluation of different engines. In order to demonstrate this we use it to compare three engines. The first is Cal3D, the most commonly used open source engine. We also introduce two engines created by the authors, Piavca and HALCA. The paper ends with a brief discussion of some other popular engines

Velocity based controllers for dynamic character animation

Dynamic character animation is a technique used to create character movements based on physics laws. Proportional derivative (PD) controllers are one of the preferred techniques in real time character simulations for driving the state of the character from its current state to a new target-state. In this paper is presented an alternative approach named velocity based controllers that are able to introduce into the dynamical system desired limbs relative velocities as constraints. As a result, the presented technique takes into account all the dynamical system to calculate the forces that transform our character from its current state to the target-state. This technique allows realtime simulation, uses a straightforward parameterization for the character muscle force capabilities and it is robust to disturbances. The paper shows the controllers capabilities for the case of human gait animation.Postprint (published version