This paper describes design principles and a system, based on reinforcement learning and procedural animation, to create an autonomous character capable of believable acting—exhibiting a responsive and expressive illusion of interactive life, grounded in its subjective experience of its world. The design principles incorporate knowledge from animation, human-computer interaction, and psychology, articulating guidelines that, when followed, support a viewer’s suspension of disbelief. The system’s reinforcement learning brain generates action, emotion, and attention signals based on motivational drives, and its procedural animation system translates those signals into expressive biophysical movement in real time. We demonstrate the system on a stylized quadruped character in a virtual habitat. In a user study, participants rated the character favorably on animacy and ability to experience emotions, which is consistent with finding the character believable.

Abstract We present Fluidymation—a new example‐based approach to stylizing animation that employs the natural dynamics of artistic media to convey a prescribed motion. In contrast to previous stylization techniques that transfer the hand‐painted appearance of a static style exemplar and then try to enforce temporal coherence, we use moving exemplars that capture the artistic medium's inherent dynamic properties, and transfer both movement and appearance to reproduce natural‐looking transitions between individual animation frames. Our approach can synthetically generate stylized sequences that look as if actual paint is diffusing across a canvas in the direction and speed of the target motion.

We present a new framework for sketch-based modeling and animation of 3D organic shapes that can work entirely in an intuitive 2D domain, enabling a playful, casual experience. Unlike previous sketch-based tools, our approach does not require a tedious part-based multi-view workflow with the explicit specification of an animation rig. Instead, we combine 3D inflation with a novel rigidity-preserving, layered deformation model, ARAP-L, to produce a smooth 3D mesh that is immediately ready for animation. Moreover, the resulting model can be animated from a single viewpoint --- and without the need to handle unwanted inter-penetrations, as required by previous approaches. We demonstrate the benefit of our approach on a variety of examples produced by inexperienced users as well as professional animators. For less experienced users, our single-view approach offers a simpler modeling and animating experience than working in a 3D environment, while for professionals, it offers a quick and casual workspace for ideation.

This paper describes the various artistic effects of watercolor and shows how they can be simulated automatically.Our watercolor model is based on an ordered set of translucent glazes, which are created independently using a shallow-water fluid simulation.We use a Kubelka-Munk compositing model for simulating the optical effect of the superimposed glazes.We demonstrate how computergenerated watercolor can be used in three different applications: as part of an interactive watercolor paint system, as a method for automatic image "watercolorization," and as a mechanism for nonphotorealistic rendering of three-dimensional scenes.