Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters

The field of Visual Analytics attempts to identify phenomena, guidelines, and algorithms to generate images suitable to communicate information efficiently and effectively. The benefit of using information visualizations is that the represented data can be quickly perceived and comprehended by the viewer. Research of novel visualization and interaction techniques in the context of three-dimensional computer graphics requires interactive computer systems. To this end, a component-oriented software framework is presented in this contribution. Bildsprache LiveLab (BiLL) allows independent implementation and combination of different components. Each component is responsible for various tasks in the context of investigating images of three-dimensional scenes. Two case studies covering multiperspective and color perspective illustrate the application of BiLL and its potential as an experimental environment for visualizing user-centered projections of three-dimensional scenes.

BiLL: an experimental environment for visual analytics

Projection of 3D space onto a 2D surface relies on the computer graphics camera, which is designed like the camera obscura The procedure follows the laws of perspective projection and does not explicitly consider the viewer of the rendered image Our approach is to extend this camera model in order to involve human perception into the rendering of 3D scenes The aim is to create a user-centred spatial impression by a 2D image By integrating the user into this process, implicit interactions can be applied to provide interfaces for an efficient and coherent communication of information in virtual environments This paper introduces user-specific and context-specific parameters that must be taken into account when designing presence-aware applications To this end, we present a concept of an interactive exhibition based on implicit interaction and point out its applicability in information design of three-dimensional scenes

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Guest login: visitor-centred information design

Computer graphics perspective is based on photography, the pin-hole camera model. This thesis examines the perspective as practiced by artists, who develop the picture geometry within the planar surface of the canvas. Their approach is flexible, depth is simulated with planar composition as the primary geometry. Renaissance artists discovered construction methods to draw the foreshortening of realistic pictures: the construction of a tiled floor in perspective was fundamental. This thesis presents the framework, a computer program, I developed to create the perspective of pictures based on the geometry practices of artists. Construction lines on the image plane simulate the 3D geometry of the pictorial space; cartoons of foreground elements are manipulated in 2D within the picture perspective; projected shadows, examples of double projection, are also included. A formalism, reformulating algebraically the straight-edge and compass evaluations, generalizes the planar geometry that solves the challenge of depicting 3D. A revised Painter’s algorithm produces the occlusions between the picture elements from sequencing them from their definitions on the canvas.

Perspective in Two Dimensions for Computer Graphics

During the design process of 3D interfaces, designer and software developer make a multitude of design decisions. The construction of a virtual scene, the texturing, and the lighting are applied methods to create effective and efficient user interfaces. In contrast, the camera model of computer graphics or rather the projection of the three-dimensional scene onto a two-dimensional image plane is often of little practical use as a tool for designing 3D interfaces. To improve the camera as an instrument in 3D interface design, the MosaIC approach (Model-Based 3D Interface Composition) is presented. The top-down approach allows designers and developers to specify 3D interfaces at multiple levels of abstraction by means of model-based interface development.

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Beyond Perspective A Model-Based Approach for Camera-Based 3D-Interface Design

Projection of three-dimensional space onto a twodimensional surface relies on the computer graphics camera based in design on the camera obscura. Geometrical limitations of this model lead to perspective distortions in wide-angle projections. Including the camera model, our approach is to involve the human perception in order to create a realistic spatial impression by a two-dimensional image. This paper discusses the influence of multi-perspective on three-dimensional computer graphics in virtual worlds based on the rules of perspective projection enhanced by characteristics of visual perception and techniques of Renaissance painting. The aim is to provide human-centered interfaces for an efficient and coherent communication of spatial information in virtual worlds to support avatarmediated interaction with its need for correct depiction of human figures concerning proportion and orientation. To this end, we explain an object-based and introduce a camera-based computer graphics procedure to prevent projective distortions and misalignments.

Figure out perspectives: perceptually realistic avatar visualization

Projection of three-dimensional space onto a two-dimensional surface relies on the computer graphics camera based in design on the camera obscura. Geometrical limitations of this model lead to perspective distortions in wide-angle projections. Including the camera model, our approach is to involve the human perception in order to create a realistic spatial impression by a two-dimensional image. The aim is to provide humancentered interfaces for an efficient and coherent communication of spatial information in virtual worlds to support avatar-mediated interaction with its need for correct depiction of human figures concerning proportion and orientation. To this end, we explain an object-based and introduce a camera-based computer graphics procedure to prevent projective distortions and misalignments.

Kerstin Kusch

Papers

Figure out perspectives: perceptually realistic avatar visualization

AN INDIVIDUAL PERSPECTIVE - Perceptually Realistic Depiction of Human Figures