Miscellaneous Visualization Projects
	Strategies for Interactive Exploration of 3D Flow Using Evenly-Spaced Illuminated Streamlines(2002-2003) This paper presents several strategies to interactively explore 3D flow. Based on a fast illuminated streamlines algorithm, standard graphics hardware is sufficient to gain interactive rendering rates. Our approach does not require the user to have any prior knowledge of flow features. After the streamlines are computed in a short preprocessing time, the user can interactively change appearance and density of the streamlines to further explore the flow. Most important flow features like velocity or pressure not only can be mapped to all available streamline appearance properties like streamline width, material, opacity, but also to streamline density. To improve spatial perception of the 3D flow we apply techniques based on animation, depth cueing, and halos along a streamline if it is crossed by another streamline in the foreground. Finally, we make intense use of focus+context methods like magic volumes, region of interest driven streamline placing, and spotlights to solve the occlusion problem.
	Christmas Tree Case Study: Computed Tomography as a Tool for Mastering Complex Real World Objects with Applications in Computer Graphics(2002)bib accepted at IEEE Visualization 2002 We report on using computed tomography (CT) as a model acquisition tool for complex objects in computer graphics. Unlike other modeling and scanning techniques the complexity of the object is irrelevant in CT, which naturally enables to model objects with, for example, concavities, holes, twists or fine surface details. Once the data is scanned, one can apply post-processing techniques aimed at its further enhancement, modification or presentation. For demonstration purposes we chose to scan a Christmas tree which exhibits high complexity which is difficult or even impossible to handle with other techniques. However, care has to be taken to achieve good scanning results with CT. Further, we illustrate the post-processing by means of data segmentation and photorealistic as well as non-photorealistic surface and volume rendering techniques.
	The Multi-Dimensional Hartley Transform as a Basis for Volume Rendering(1999) The Fast Hartley Transform (FHT), a discrete version of the Hartley Transform (HT), has been studied in various papers and shown to be faster and more convenient to implement and handle than the corresponding Fast Fourier Transform (FFT). As the HT is not as nicely separable as the Fourier Transform (FT), a multidimensional version of the HT needs to perform a final correction step to convert the result of separate HTs for each dimension into the final multi-dimensional transform. Although there exist algorithms for two and three dimensions, no generalization to arbitrary dimensions can be found in the literature. We demonstrate an easily comprehensible and efficient implementation of the fast HT and its multi-dimensional extension. By adapting this algorithm to volume rendering by the projection-slice theorem and by the use for filter analysis in frequency domain we further demonstrate the importance of the HT in this application area.
	AlVis - An Aluminium-Foam Visualization and Investigation Tool(1999) In recent years there has been an increased interest in metal foams in the field of material science. The stress absorbing potential is one of the most interesting properties for the application of aluminium foam (e.g. car manufacturing). Material scientists need to investigate the structure of metal foams in order to optimize their deformation behavior. An interactive tool for the investigation is presented in this paper.
	Smurf - a smart surface model for advanced visualization techniques (1998) Highly elaborated visualization techniques that are based on surfaces often are independent from the origin of the surface data. For re-using advanced visualization methods for surfaces of various kind, we developed an abstract surface interrogation layer called SMURF. In this paper we discuss the steps necessary to unify multiple types of surfaces under a shared general purpose interface.
	VisCof: A Java-Applet-Interface Builder in Java (1996-1997) Visual Coffee is an java-applet-development-environment, which for itself is written in Java. Similar to Visual Basic and other graphical development environments the user composes an applet by placing control-objects (buttons, textfields, ...) into the bare applet. Java-Sourcecode can be added in methods, which are assigned to events of the control-objects.
	TunVis: Visualizing specific geologic features for tunnel planning and construction (1997) This is a project on the visualization of virtual tunnels by using data of existing geologic rock formations.

Institute of Computer Graphics / Visualization and Animation Group / Research

This page is maintained by Helwig Löffelmann. It was last updated on January 5, 2000.
If you have any comments, please send a message to helwig@cg.tuwien.ac.at.