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Hybrid visibility compositing and masking for illustrative rendering.

Bruckner S, Rautek P, Viola I, Roberts M, Sousa MC, Gröller ME - Comput Graph (2010)

Bottom Line: These tools behave just like in 2D, but their influence extends beyond a single viewpoint.Since the presented approach makes no assumptions about the underlying rendering algorithms, layers can be generated based on polygonal geometry, volumetric data, point-based representations, or others.Our implementation exploits current graphics hardware and permits real-time interaction and rendering.

View Article: PubMed Central - PubMed

Affiliation: Institute of Computer Graphics and Algorithms, Vienna University of Technology, Austria.

ABSTRACT
In this paper, we introduce a novel framework for the compositing of interactively rendered 3D layers tailored to the needs of scientific illustration. Currently, traditional scientific illustrations are produced in a series of composition stages, combining different pictorial elements using 2D digital layering. Our approach extends the layer metaphor into 3D without giving up the advantages of 2D methods. The new compositing approach allows for effects such as selective transparency, occlusion overrides, and soft depth buffering. Furthermore, we show how common manipulation techniques such as masking can be integrated into this concept. These tools behave just like in 2D, but their influence extends beyond a single viewpoint. Since the presented approach makes no assumptions about the underlying rendering algorithms, layers can be generated based on polygonal geometry, volumetric data, point-based representations, or others. Our implementation exploits current graphics hardware and permits real-time interaction and rendering.

No MeSH data available.


Related in: MedlinePlus

Two viewpoints for a magic lens effect generated using our compositing framework.
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fig10: Two viewpoints for a magic lens effect generated using our compositing framework.

Mentions: In addition to the visibility operator, we provide a simple but powerful extension of conventional blending operators which allows them to make use of the additional spatial information. This includes the operators of the Porter–Duff algebra, such as over, atop, in, and out, as well as further operators typically present in image manipulation software (e.g., multiply, screen, or overlay). Our framework allows the use of all these operators in combination with a blending weight based on the distance between the layer's depth z and the current depth of the intermediate composite zf. The layer's opacity is multiplied by the blending weight wo which is computed by(3)wo=1ifβz<βzf1−Δz(z,zf,/β/)otherwisewhere is a user-controlled parameter of the operator. If is zero (the default value), the operator will behave exactly like its two-dimensional counterpart. If , the parts in front of the intermediate image will be shown and parts behind it will decrease in opacity with increasing distance. Conversely, if parts behind the current depth of the intermediate composite will be shown with full opacity and parts in front of it will decrease in opacity with increasing distance. This enables smooth fading of layers based on occlusion relationships. For instance, two layers containing different representations of the same object can be used to make it shine through an occluding layer with a different appearance. This effect is demonstrated in Fig. 10 where an occlusion-based plus operator is used to show an X-ray style representation of the hand where it is occluded by the lens of the magnifying glass.


Hybrid visibility compositing and masking for illustrative rendering.

Bruckner S, Rautek P, Viola I, Roberts M, Sousa MC, Gröller ME - Comput Graph (2010)

Two viewpoints for a magic lens effect generated using our compositing framework.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2925605&req=5

fig10: Two viewpoints for a magic lens effect generated using our compositing framework.
Mentions: In addition to the visibility operator, we provide a simple but powerful extension of conventional blending operators which allows them to make use of the additional spatial information. This includes the operators of the Porter–Duff algebra, such as over, atop, in, and out, as well as further operators typically present in image manipulation software (e.g., multiply, screen, or overlay). Our framework allows the use of all these operators in combination with a blending weight based on the distance between the layer's depth z and the current depth of the intermediate composite zf. The layer's opacity is multiplied by the blending weight wo which is computed by(3)wo=1ifβz<βzf1−Δz(z,zf,/β/)otherwisewhere is a user-controlled parameter of the operator. If is zero (the default value), the operator will behave exactly like its two-dimensional counterpart. If , the parts in front of the intermediate image will be shown and parts behind it will decrease in opacity with increasing distance. Conversely, if parts behind the current depth of the intermediate composite will be shown with full opacity and parts in front of it will decrease in opacity with increasing distance. This enables smooth fading of layers based on occlusion relationships. For instance, two layers containing different representations of the same object can be used to make it shine through an occluding layer with a different appearance. This effect is demonstrated in Fig. 10 where an occlusion-based plus operator is used to show an X-ray style representation of the hand where it is occluded by the lens of the magnifying glass.

Bottom Line: These tools behave just like in 2D, but their influence extends beyond a single viewpoint.Since the presented approach makes no assumptions about the underlying rendering algorithms, layers can be generated based on polygonal geometry, volumetric data, point-based representations, or others.Our implementation exploits current graphics hardware and permits real-time interaction and rendering.

View Article: PubMed Central - PubMed

Affiliation: Institute of Computer Graphics and Algorithms, Vienna University of Technology, Austria.

ABSTRACT
In this paper, we introduce a novel framework for the compositing of interactively rendered 3D layers tailored to the needs of scientific illustration. Currently, traditional scientific illustrations are produced in a series of composition stages, combining different pictorial elements using 2D digital layering. Our approach extends the layer metaphor into 3D without giving up the advantages of 2D methods. The new compositing approach allows for effects such as selective transparency, occlusion overrides, and soft depth buffering. Furthermore, we show how common manipulation techniques such as masking can be integrated into this concept. These tools behave just like in 2D, but their influence extends beyond a single viewpoint. Since the presented approach makes no assumptions about the underlying rendering algorithms, layers can be generated based on polygonal geometry, volumetric data, point-based representations, or others. Our implementation exploits current graphics hardware and permits real-time interaction and rendering.

No MeSH data available.


Related in: MedlinePlus