Crowdbrush: Interactive Authoring of Real-time Crowd Scenes

Branislav Ulicny, Pablo de Heras Ciechomski and Daniel Thalmann

Virtual Reality Lab, EPFL

Virtual audience Colored spotlight
Specular highlights shading
Color brush Creation brush Pedestrian crowd Cartoon shading


Abstract: Recent advances in computer graphics techniques and increasing power of graphics hardware made it possible to display and animate large crowds in real-time. Most of the research efforts have been directed towards improving rendering or behavior control; the question how to author crowd scenes in an efficient way is usually not addressed. We introduce a novel approach to create complex scenes involving thousands of animated individuals in a simple and intuitive way. By employing a brush metaphor, analogous to the tools used in image manipulation programs, we can distribute, modify and control crowd members in real-time with immediate visual feedback. We define concepts of operators and instance properties that allow to create and manage variety in populations of virtual humans. An efficient technique allowing to render up to several thousands of fully three-dimensional polygonal characters with keyframed animations at interactive framerates is presented. The potential of our approach is demonstrated by authoring a scenario of a virtual audience in a theater and a scenario of a pedestrian crowd in a city.


Reference

Ulicny B., de Heras P., Thalmann D., “Crowdbrush: Interactive Authoring of Real-time Crowd Scenes”, Proc. ACM SIGGRAPH/Eurographics Symposium on Computer Animation ‘04, 2004.

Videos

Brushes Virtual audience Pedestrian crowd
Brushes, DivX (11 MB) Audience, DivX (6.5 MB) Pedestrians, DivX (16 MB)


Design: Mireille Clavien, Stephanie Noverraz, Rachel Cetre