VIS Home of Joachim Diepstraten

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 Research Activities                              

[2003][2002]

Year 2004

In collaboration with Ralf Botchen - Extending the Interactive cutaway illustration algorithm to an interactive toolkit

The previous OpenGL version from last year of the interactive cutaway illustration algorithm has been ported to Direct3D 9 using pixel shader 2.0 increasing the rendering speed and flexibility of the system. This version now also includes a real user interface that allows to set diverse rendering options. A first version to create an interactive toolkit for generating technical illustrations was set with the new version. It is now possible to render the object in different rendering styles including a newly developed airbrush style and it is even possible to mix between different rendering styles. The user can now interact with the cuting geometry and place it freely in the 3D world.

Results:
Paper: --
Images:
Videos: --
Downloads:Version 1.0b of Toolkit requires DX9 PS2.0 card3.8Mbyte

In collaboration with Andreas Hub - Design and development of an indoor navigation and object identification system for the blind

A first step of desiging a new system that assists blind users in orienting themselves in indoor environments has been made. A first primarily version of a sensor module that can be handled like a flashlight by a blind user has been developed. It can be used for searching tasks within the three-dimensional environment. By pressing keys, inquiries concerning object characteristics, position, orientation and navigation can be sent to a connected portable computer, or to a federation of data servers providing models of the environment. Finally these inquiries are acoustically answered over a text-to-speech engine. A three-dimensional model of the surrounding is used to first find virtual corresponding objects in a 3D scenegraph.

Results:
Paper: Design and Development of an Indoor Navigation and Object Identification System for the Blind ACM ASSETS 2004
Images: --
Videos: --
Downloads:--

Development of a novel transparency model for interactive rendering applications

A novel color transparency model for surface shading for interactive computer graphics has been developed. It is based directly on the physical filter model for color transparency and incorporates latest human psychophysical results in this area. Comparisons for chromatic and achromatic cases have been taken between other transparency models either frequently used in computer graphics today or not even widely considered yet, showing clear differences between the individual models. It can be demonstrated that the model produces transparent impressions which lie closer to the visual appearance of real transparent surfaces. The transparency model itself can be implemented with current programmable shader hardware and is therefore able to run in all sort of interactive graphical applications today.

Results:
Paper: --
Images:
Videos: --
Downloads:--

Rendering of transparent and reflective surfaces in cel shading

An extension to common realtime toon/cel-shading rendering techniques for treating reflective and transparent surfaces in a 3D toon-shading environment has been developed. The approach takes advantage of multi-texturing hardware and simple fragment and vertex shader programs. This allows a broad usage in interactive applications

Results:
Paper: Interactive Rendering of Reflective and Transmissive Surfaces in 3D Toon Shading GI Workshop Computer Games 2004
Images:
Videos: Demo movie 1 17.5Mbytes (QuickTime 6) Demo movie 2 15Mbytes (QuickTime 6)
Downloads:--

In collaboration with Mike Eissele - In-Depth performance analysis of fragment and texture operations of programable DirectX9 graphics hardware

Detailed performance of DirectX9 shading hardware was carried out to check the influence of different fragment and texture operations in the fragment processing pipeline of the most common GPU architectures. A special written standalone testing program was developed that allows to measure arbitrary pixel shading programs concerning their performance impact on the rendering time. A detailed look at different assembly level operations in these shader programs and diverse texture formats and texture operations was carried out on diverse DirectX9 pixel shader 2.0 compatible cards

Results:
Paper: Article in Shader X^3 Wolfgang Engel Charles River Media
Images: --
Videos: --
Downloads: Coming as soon as the book has been published the benchmark software will be made available

In collaboration with the former student Martin Görke - Design and implementation of an alternative rendering system for mobile devices.

Since right now mobile devices are very limited concerning graphical resources basically only simple 2D rasterization operations are available, that run completely on the main CPU of the device. The desire to have more complex 3D graphics on these devices often results in a remote rendering solution. Classical remote rendering solutions produce the final images on a server and transfer these to the client device over a wired or non-wired network. We developed an alternative method to the image-based approach by splitting the rendering process between client and server transfering couple of 2D line primitives over the network, which are rendered locally by the mobile device.

Results:
Paper: Remote Line Rendering for Mobile Devices CGI'2004
Images:
Videos: --
Downloads:Win32/OpenGL Remote line render server executable46Kbyte Pocket PC 2002/3 ARM client executable23Kbyte

In collaboration with the former student Michael Braitmaier - Realtime rendering of seasonal influenced trees.

An algorithm for the visualization of trees during the passing of the year, taking into account the changing and vanishing of the tree's leaves as well as their color changes has been developed. In combination with the Phong lighting algorithm the color changes are directly integrated into the lighting model. The implementation uses graphics hardware shader programs to increase the performance to a realtime rendering of complex trees. In contrast to other previous works our approach relies more on theoretical foundation of biological and chemical insights, taking into account botanic research results about biochemical reactions influencing the leaves' pigments during the season.

Results:
Paper: Real-Time Rendering of Seasonal Influenced Trees TPCG'2004
Images:
Videos: Simulation of a tree during the year 10Mbytes (AVI/DivX 5 codec)
Downloads:--

In collaboration with Daniel Weiskopf and Martin Kraus - Design of a graphics hardware extension allowing the relocation of fragments.

An extension to the pixel pipeline of current programmable rasterization hardware to include the possibility to freely locate the rasterization position of fragments and pixels has been developed. With the work it was possible to show that this new functionality could lead to a new and wider class of algorithms in computer graphics. For testing a GPU-assisted simulator for running on the proposed architecture was developed.

Results:
Paper: Vragments - Relocatability as an Extension to Programmable Rasterization Hardware WSCG'2004
Images:
Videos: Exploding teapot using Vragments 2.8Mbytes (AVI/CinePak codec)
Downloads:--


 Personal Activities                              

For personal activities better go there


Last modified 26 Nov 2004
by Joachim Diepstraten