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207
Volume Illustration: Non-Photorealistic Rendering of Volume Models
- IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS
, 2001
"... Accurately and automatically conveying the structure of a volume model is a problem not fully solved by existing volume rendering approaches. Physics-based volume rendering approaches create images which may match the appearance of translucent materials in nature, but may not embody important struct ..."
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Cited by 190 (18 self)
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Accurately and automatically conveying the structure of a volume model is a problem not fully solved by existing volume rendering approaches. Physics-based volume rendering approaches create images which may match the appearance of translucent materials in nature, but may not embody important structural details. Transfer function approaches allow flexible design of the volume appearance, but generally require substantial hand tuning for each new data set in order to be effective. We introduce the volume illustration approach, combining the familiarity of a physics-based illumination model with the ability to enhance important features using non-photorealistic rendering techniques. Since features to be enhanced are defined on the basis of local volume characteristics rather than volume sample value, the application of volume illustration techniques requires less manual tuning than the design of a good transfer function. Volume illustration provides a flexible unified framework for enhancing structural perception of volume models through the amplification of features and the addition of illumination effects.
Interactive ray tracing
- In Symposium on interactive 3D graphics
, 1999
"... University of Utah, We examine a rendering system that interactively ray traces an image on a conventional multiprocessor. The implementation is “brute force ” in that it explicitly traces rays through every screen pixel, yet pays careful attention to system resources for acceleration. The design of ..."
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Cited by 176 (28 self)
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University of Utah, We examine a rendering system that interactively ray traces an image on a conventional multiprocessor. The implementation is “brute force ” in that it explicitly traces rays through every screen pixel, yet pays careful attention to system resources for acceleration. The design of the system is described, along with issues related to material models, lighting and shadows, and frameless rendering. The system is demonstrated for several different types of input scenes.
Curvature-based transfer functions for direct volume rendering: Methods and applications
- In Proceedings of IEEE Visualization 2003
, 2003
"... Figure 1: Volume renderings of a 64 3 synthetic volume with four different curvature measures. Left to right: first principal curvature κ ..."
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Cited by 157 (11 self)
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Figure 1: Volume renderings of a 64 3 synthetic volume with four different curvature measures. Left to right: first principal curvature κ
Interactive technical illustration
- In Proceedings of the 1999 symposium on Interactive 3D graphics
, 1999
"... A rendering is an abstraction that favors, preserves, or even emphasizes some qualities while sacrificing, suppressing, or omitting other characteristics that are not the focus of attention. Most computer graphics rendering activities have been concerned with photorealism, i.e., trying to emulate an ..."
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Cited by 117 (8 self)
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A rendering is an abstraction that favors, preserves, or even emphasizes some qualities while sacrificing, suppressing, or omitting other characteristics that are not the focus of attention. Most computer graphics rendering activities have been concerned with photorealism, i.e., trying to emulate an image that looks like a highquality photograph. This laudable goal is useful and appropriate in many applications, but not in technical illustration where elucidation of structure and technical information is the preeminent motivation. This calls for a different kind of abstraction in which technical communication is central, but art and appearance are still essential instruments toward this end. Work that has been done on computer generated technical illustrations has focused on static images, and has not included all of the techniques used to hand draw technical illustrations. A paradigm for the display of technical illustrations in a dynamic environment is presented. This display environment includes all of the benefits of computer generated technical illustrations, such as a clearer picture of shape, structure, and material composition than traditional computer graphics methods. It also includes the three-dimensional interactive strength of modem display systems. This is accomplished by using new algorithms for real time drawing of silhouette curves, algorithms which solve a number of the problems inherent in previous methods. We incorporate current non-photorealistic lighting methods, and augment them with new shadowing algorithms based on accepted techniques used by artists and studies carried out in human perception. This paper, all of the images, and a mpeg video clip are available at
Volumeshop: An interactive system for direct volume illustration
- PROCEEDINGS OF IEEE VISUALIZATION 2005
, 2005
"... Illustrations play a major role in the education process. Whether used to teach a surgical or radiologic procedure, to illustrate normal or aberrant anatomy, or to explain the functioning of a technical device, illustration significantly impacts learning. Although many specimens are readily availabl ..."
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Cited by 114 (21 self)
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Illustrations play a major role in the education process. Whether used to teach a surgical or radiologic procedure, to illustrate normal or aberrant anatomy, or to explain the functioning of a technical device, illustration significantly impacts learning. Although many specimens are readily available as volumetric data sets, particularly in medicine, illustrations are commonly produced manually as static images in a time-consuming process. Our goal is to create a fully dynamic three-dimensional illustration environment which directly operates on volume data. Single images have the aesthetic appeal of traditional illustrations, but can be interactively altered and explored. In this paper we present methods to realize such a system which combines artistic visual styles and expressive visualization techniques. We introduce a novel concept for direct multi-object volume visualization which allows control of the appearance of inter-penetrating objects via two-dimensional transfer functions. Furthermore, a unifying approach to efficiently integrate many non-photorealistic rendering models is presented. We discuss several illustrative concepts which can be realized by combining cutaways, ghosting, and selective deformation. Finally, we also propose a simple interface to specify objects of interest through three-dimensional volumetric painting. All presented methods are integrated into VolumeShop, an interactive hardware-accelerated application for direct volume illustration.
Stylized rendering techniques for scalable real-time 3d animation
, 2000
"... “We’re searching here, trying to get away from the cut and dried handling of things all the way through—everything—and the only way to do it is to leave things open until we have completely explored every bit of it.” –Walt Disney Researchers in nonphotorealistic rendering (NPR) have investigated a v ..."
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Cited by 106 (0 self)
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“We’re searching here, trying to get away from the cut and dried handling of things all the way through—everything—and the only way to do it is to leave things open until we have completely explored every bit of it.” –Walt Disney Researchers in nonphotorealistic rendering (NPR) have investigated a variety of techniques to simulate the styles of artists. Recent work has resulted in methods for pen-and-ink illustration, pencil sketching, watercolor, engraving, and silhouette edge rendering. This paper presents real-time methods to emulate cartoon styles. We also present variations on a texture mapping technique to achieve real-time pencil sketching. We demonstrate our method of inking silhouettes, material and mesh boundaries, and crease edges. In addition, we present techniques for emphasizing motion of cartoon objects by introducing geometry into the cartoon scene. The rendering system is integrated with an animation system and a runtime multiresolution mesh (MRM) system to achieve scalability, ensuring real-time performance on any platform. Such solutions allow us to take advantage of evolving hardware in order to make nonphotorealistic animation and rendering achievable on low- and high-end consumer platforms. All of the techniques described can be applied to models created with standard modeling tools and require no additional mark-up information from the modeler.
Silhouette Clipping
, 2000
"... Approximating detailed models with coarse, texture-mapped meshes results in polygonal silhouettes. To eliminate this artifact, we introduce silhouette clipping, a framework for efficiently clipping the rendering of coarse geometry to the exact silhouette of the original model. The coarse mesh is obt ..."
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Cited by 102 (8 self)
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Approximating detailed models with coarse, texture-mapped meshes results in polygonal silhouettes. To eliminate this artifact, we introduce silhouette clipping, a framework for efficiently clipping the rendering of coarse geometry to the exact silhouette of the original model. The coarse mesh is obtained using progressive hulls, a novel representation with the nesting property required for proper clipping. We describe an improved technique for constructing texture and normal maps over this coarse mesh. Given a perspective view, silhouettes are efficiently extracted from the original mesh using a precomputed search tree. Within the tree, hierarchical culling is achieved using pairs of anchored cones. The extracted silhouette edges are used to set the hardware stencil buffer and alpha buffer, which in turn clip and antialias the rendered coarse geometry. Results demonstrate that silhouette clipping can produce renderings of similar quality to high-resolution meshes in less rendering time.
H.: HighQuality Two-Level Volume Rendering of Segmented Data Sets on Consumer Graphics Hardware
- In IEEE Visualization ’03 (2003
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Artistic silhouettes: a hybrid approach
- In Proceedings of NPAR 2000
, 2000
"... We present a new algorithm for rendering silhouette outlines of 3D polygonal meshes with stylized strokes. Rather than use silhouette edges of the model directly as the basis for drawing strokes, we first process the edges in image space to create long, connected paths corresponding to visible porti ..."
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Cited by 86 (5 self)
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We present a new algorithm for rendering silhouette outlines of 3D polygonal meshes with stylized strokes. Rather than use silhouette edges of the model directly as the basis for drawing strokes, we first process the edges in image space to create long, connected paths corresponding to visible portions of silhouettes. The resulting paths have the precision of object-space edges, but avoid the unwanted zig-zagging and inconsistent visibility of raw silhouette edges. Our hybrid screen/object space approach thus allows us to apply stylizations to strokes that follow the visual silhouettes of an object. We describe details of our OpenGL-based stylized strokes that can resemble natural media, but render at interactive rates. We demonstrate our technique with the accompanying still images and animations rendered with our technique.
Art-based rendering of fur, grass, and trees
- Proceedings of SIGGRAPH 99
, 1999
"... Artists and illustrators can evoke the complexity of fur or vegetation with relatively few well-placed strokes. We present an algorithm that uses strokes to render 3D computer graphics scenes in a stylized manner suggesting the complexity of the scene without representing it explicitly. The basic al ..."
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Cited by 83 (11 self)
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Artists and illustrators can evoke the complexity of fur or vegetation with relatively few well-placed strokes. We present an algorithm that uses strokes to render 3D computer graphics scenes in a stylized manner suggesting the complexity of the scene without representing it explicitly. The basic algorithm is customizable to produce a range of effects including fur, grass and trees, as we demonstrate in this paper and accompanying video. The algorithm is implemented within a broader framework that supports procedural stroke-based textures on polyhedral models. It renders moderately complex scenes at multiple frames per second on current graphics workstations, and provides some interframe coherence.
