REDDY M. 1997. "Perceptually Modulated Level of Detail for Virtual Environments". Ph.D. Thesis (CST- 13497) , University of Edinburgh.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....ahshima et al. described a system for gazedirected stereoscopic rendering [21]again using heuristic models of eccentricity, velocity, and convergence to guide selection ofprecomputed LaDs. Reddy was the first to attempt an LaD selection system guided throughout by a principled perceptual model [24]. Using images rendered from multiple viewpoints, Reddy analyzed the frequency content of objects and their LaDs, A model of the visual acuity, defined as highest perceptible spatial frequency, guided LaD selection: if a high resolution and a low resolution LaD differed only at frequencies beyond ....

....temporal contrast sensitivity to address possible flicker artifacts in interactive or animated rendering. Finally, we would like to exploit the reduced visual acuity caused by velocity across the retinal field, which Reddy s work suggests provides a promising opportunity for further simplification [24]. 5 ....

Reddy, Martin. "Perceptually-Modulated Level of Detail for Virtual Environments", Ph.D. thesis, University of Edinburgh, 1997.

....details that cannot be rendered by the hardware. Methods based on distance and object size fall in this group. In another group we have algorithms that try to strip away details that could not be perceived by the human viewer. These are methods based on eccentricity, depth of field and velocity [Red97]. There is also another method with the main goal of maintaining a constant high frame rate, regardless of the complexity of the model. 3.1.1 Culling There are certain situations when some parts of the geometry are never seen by the user. In these cases, those parts are not represented by the ....

Martin Reddy. Perceptually Modulated Level of Detail for Virtual Environments. PhD dissertation, University of Edinburgh, 1997.

....the connections between objects remain ignored. 2.2 Psychophisical considerations 2.2.1 Visual perception of levels of details The use of levels of details is based on the assumption that the perception of details varies with the apparent size or speed of object. This was validated by Reddy [3] who used the characteristics of the human visual system to introduce contrast sensitivity functions in order to determine the perception of features in a scene and decide which version of an object should be chosen without the simplification being noticeable. He showed that level of details ....

Martin Reddy. Perceptually Modulated Level of Detail for Virtual Environments. PhD thesis, University of Edinburgh, 1997.

....three perceptual effects, and the method for combining all three effects to choose an LOD, appear to have been determined empirically. Thus their algorithm, while clearly demonstrating the potential of a gaze directed approach, still employs a fundamentally heuristic model of the visual system. Reddy 97] was the first to attempt an LOD selection system guided throughout by a rigorous model of the human perceptual system. Using the psychophysical findings described below, Reddy analyzes the frequency content of objects and their LODs from multiple viewpoints. A model of the visual acuity, or ....

....to contrast threshold and spatial frequency by the equation: 9 . 45 ) 2 ( 2 2 3 10 ) 3 ( log 3 . 7 1 . 6 1 = v Threshold e v v c a a [Equation 4] Here v is the velocity of a contrast grating measured in degrees per second across the visual field. Experiments by [Reddy 97] confirmed the abstract relationship within Kelly s equation, but found different constants. To avoid introducing more than one variable in our perceptual metrics, we elected to concentrate on peripheral degradation due to eccentricity, and currently ignore the additional degradation introduced ....

Reddy, Martin. "Perceptually-Modulated Level of Detail for Virtual Environments", Ph.D. thesis, University of Edinburgh, 1997.

....to get the chaining information. 4 Evaluation and Performance Experiments. The aim of these experiments was to evaluate the loss of information when simplifying virtual 3D objects. Reddy showed that the caracteristics of the human visual system can be used to control the simplification objects [8]. We extend these results by showing that simplifications can be used at levels which are perceivable because cognitive processes facilitate the recognition of objects. We tested the perceptual behavior of various types of users to determine the effect of field knowledge: workers from the piping ....

M. Reddy. Perceptually Modulated Level of Detail for Virtual Environments. PhD thesis, University of Edinburgh, 1997.

....the connections between objects remain ignored. 2.2 Psychophisical considerations 2.2.1 Visual perception of levels of details The use of levels of details is based on the assumption that the perception of details varies with the apparent size or speed of object. This was validated by Reddy [3] who used the characteristics of the human visual system to introduce contrast sensitivity functions in order to determine the perception of features in a scene and decide which version of an object should be chosen without the simplification being noticeable. He showed that level of details ....

Martin Reddy. Perceptually Modulated Level of Detail for Virtual Environments. PhD thesis, University of Edinburgh, 1997.

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REDDY M. 1997. "Perceptually Modulated Level of Detail for Virtual Environments". Ph.D. Thesis (CST- 13497) , University of Edinburgh.

No context found.

M. Reddy. Perceptually Modulated Level of Detail for Virtual Environments. Ph.D. Thesis, University of Edinburgh, 1997.

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