RenderMan in production at WDFA

Pritchett, Heather; Lancaster, Tal

doi:10.1145/1185657.1185820

3D unsharp masking for scene coherent enhancement

Ritschel¹,

Smith²,

Ihrke³

et al. 2008

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Figure 1: A naturally illuminated 3D scene (left) and the same scene with 3D unsharp masking enhancement (center). Our enhancement technique is coherent with the scene itself, not simply with each rendered frame, permits arbitrary lighting and is temporally coherent. AbstractWe present a new approach for enhancing local scene contrast by unsharp masking over arbitrary surfaces under any form of illumination. Our adaptation of a well-known 2D technique to 3D interactive scenarios is designed to aid viewers in tasks like understanding complex or detailed geometric models, medical visualization and navigation in virtual environments. Our holistic approach enhances the depiction of various visual cues, including gradients from surface shading, surface reflectance, shadows, and highlights, to ease estimation of viewpoint, lighting conditions, shapes of objects and their world-space organization. Motivated by recent perceptual findings on 3D aspects of the Cornsweet illusion, we create scene coherent enhancements by treating cues in terms of their 3D context; doing so has a stronger effect than approaches that operate in a 2D image context and also achieves temporal coherence. We validate our unsharp masking in 3D with psychophysical experiments showing that the enhanced images are perceived to have better contrast and are preferred over unenhanced originals. Our operator runs at real-time rates on a GPU and the effect is easily controlled interactively within the rendering pipeline.

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3D unsharp masking for scene coherent enhancement

Ritschel¹,

Smith²,

Ihrke³

et al. 2008

ACM SIGGRAPH 2008 Papers

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Figure 1: A naturally illuminated 3D scene (left) and the same scene with 3D unsharp masking enhancement (center). Our enhancement technique is coherent with the scene itself, not simply with each rendered frame, permits arbitrary lighting and is temporally coherent. AbstractWe present a new approach for enhancing local scene contrast by unsharp masking over arbitrary surfaces under any form of illumination. Our adaptation of a well-known 2D technique to 3D interactive scenarios is designed to aid viewers in tasks like understanding complex or detailed geometric models, medical visualization and navigation in virtual environments. Our holistic approach enhances the depiction of various visual cues, including gradients from surface shading, surface reflectance, shadows, and highlights, to ease estimation of viewpoint, lighting conditions, shapes of objects and their world-space organization. Motivated by recent perceptual findings on 3D aspects of the Cornsweet illusion, we create scene coherent enhancements by treating cues in terms of their 3D context; doing so has a stronger effect than approaches that operate in a 2D image context and also achieves temporal coherence. We validate our unsharp masking in 3D with psychophysical experiments showing that the enhanced images are perceived to have better contrast and are preferred over unenhanced originals. Our operator runs at real-time rates on a GPU and the effect is easily controlled interactively within the rendering pipeline.

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Approximating dynamic global illumination in image space

Ritschel¹,

Grosch²,

Seidel³

2009

Proceedings of the 2009 Symposium on Interactive 3D Graphics and Games

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Figure 1: We generalize screen-space ambient occlusion (SSAO) to directional occlusion (SSDO) and one additional diffuse indirect bounce of light. This scene contains 537k polygons and runs at 20.4 fps at 1600×1200 pixels. Both geometry and lighting can be fully dynamic. AbstractPhysically plausible illumination at real-time framerates is often achieved using approximations. One popular example is ambient occlusion (AO), for which very simple and efficient implementations are used extensively in production. Recent methods approximate AO between nearby geometry in screen space (SSAO). The key observation described in this paper is, that screen-space occlusion methods can be used to compute many more types of effects than just occlusion, such as directional shadows and indirect color bleeding. The proposed generalization has only a small overhead compared to classic SSAO, approximates direct and one-bounce light transport in screen space, can be combined with other methods that simulate transport for macro structures and is visually equivalent to SSAO in the worst case without introducing new artifacts. Since our method works in screen space, it does not depend on the geometric complexity. Plausible directional occlusion and indirect lighting effects can be displayed for large and fully dynamic scenes at real-time frame rates.

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RenderMan in production at WDFA

Cited by 4 publications

References 0 publications

3D unsharp masking for scene coherent enhancement

3D unsharp masking for scene coherent enhancement

3D unsharp masking for scene coherent enhancement

Approximating dynamic global illumination in image space

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