Browsing by Author "Schmidt, Ryan"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- ItemOpen AccessImplicit Sweep Surfaces(2005-04-29) Wyvill, Brian; Schmidt, RyanA technique is presented for generating implicit sweep objects that support direct specification and manipulation of the surface with no topological limitations on the 2D sweep template. The novelty of this method is that the underlying scalar field is bounded and C1 continuous, apart from surface creases. Bounded scalar fields guarantee local in- fluence when modeling with implicit surfaces, an important usbility requirement for interactive modeling. A discrete approximation is also described that supports fast evaluation for bounded scalar fields. The new sweep objects are implemented in an interactive BlobTree modeling tool, providing an intuitive and expressive free-form implicit modeling component. This sweep representation permits conversion of parametric sweep surfaces to implicit volumes. An application to volume reconstruction from parallel contours is also explored.
- ItemOpen AccessInteractive Decal Compositing with Discrete Exponential Maps(2006-04-11) Schmidt, Ryan; Grimm, Cindy; Wyvill, BrianA method is described for texturing surfaces using decals, images placed on the surface using local parameterizations. Decal parameterizations are generated with a novel O(N logN) discrete approximation to the exponential map which requires only a single additional step in Dijkstra s graph-distance algorithm. Decals are dynamically composited in an interface that addresses many limitations of previous work. Tools for image processing, deformation/feature-matching, and vector graphics are implemented using direct surface interaction. Exponential map decals can contain holes and can also be combined with conformal parameterization to reduce distortion. The exponential map approximation can be computed on any point set, including meshes and sampled implicit surfaces, and is relatively stable under resampling. The decals stick to the surface as it is interactively deformed, allowing the texture to be preserved even if the surface changes topology. These properties make exponential map decals a suitable approach for texturing animated implicit surfaces.
- ItemOpen AccessInteractive modeling with implicit surfaces(2006) Schmidt, Ryan; Wyvill, Brian
- ItemOpen AccessMAD Boxes: A Plug-And-Play Tiled Display Wall(2005-03-16) Schmidt, Ryan; Penner, Eric; Carpendale, SheelaghWhile interest in large displays is growing rapidly, they are still not common-place. Significant technical knowledge is required to construct and maintain current display wall systems. Our goal is to make large tiled-projector displays essentially plug and play . We want a design that can be incrementally expanded and reconfigured at will. We want a software environment that is identical to a standard desktop computer, with no need for rendering clusters and special libraries. We have designed a display wall solution that meets our needs. With our Modular Ambient Display (MAD) boxes, a variety of high-resolution large display configurations can be quickly assembled. By integrating interaction hardware into each box, we have created a stand-alone interactive large display component. Our system permits experimentation not only with the wall software, but the physical wall configuration as well.
- ItemOpen AccessSPINALTAP: AN ARCHITECTURE FOR REAL-TIME VERTEBRAE DRILLING SIMULATION(2002-09-27) Schmidt, RyanThis report describes the implementation of the SpinalTap virtual spinal surgery simulation system. The goal of the system is to simulate drilling into vertebrae. Two methods for reconstructing a vertebrae from CT scan data are presented. Several models of an L3 vertebrae are reconstructed with varying results. An architecture for real-time high speed decimation of point volumes is explained and implemented. Simulations performed with test data show collision testing rates of over 400Hz on current PC hardware.