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psychological cues of computer graphics start learning
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perspective shortening, occlusion of objects, light and shadow, texture gradients, atmospheric perspective
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start learning
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1949- first CG on a computer at MIT, 1956-sensorama, 1962-sketchpad the first interactive CG system, 1965-VR challenges(sutherland), 1968-the ultimate display of Sutherland
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visible light + good and bad conditions start learning
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380(violet)-780(red), around 625 in bad conditions(scotopic), around 780 in good conditions(photopic)
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) Why is stereoscopic vision alone not sufficient to fulfill all visual representation requirements of Virtual Reality? start learning
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Stereoscopic vision ⇒ illusion of depth in an image by presenting two offset images separately to the left and right eye • But: motion parallax is missing ⇒ no realistic feedback during motions of the users’ head
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What additional feature has to be included to provide a “holographic” perception? and what kinda hardware is required for this? start learning
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User centered projection ⇒ Perspective has to be adapted to the users position and orientation? 2. Tracking system
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Discuss the pros and cons of electro-magnetic and opto-electronic tracking systems, respectively (electro) start learning
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electro-magnetic: • + position and orientation • + no occlusion • - sensitive to ferromagnetic materials in the environment • - accuracy decreases with growing distance between sender and receiver • - rather large sensors (1–2 cm) • - cabling
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Discuss the pros and cons of electro-magnetic and opto-electronic tracking systems, respectively (opto) start learning
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opto-electronic: • +accuracy • + passive markers available: no cabling, nearly non-intrusive + latency (-occlusion -no orientation (combine 3 non-collinear markers) -calibration process (rather comfortable in today’s systems)
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start learning
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When watching an object close to us, our eyes point slightly inward. This difference in the direction of the eyes is called convergence
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start learning
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As our eyes see the world from slightly different locations, the images sensed by the eyes are slightly different. This difference is called Binocular Paralax. binocular parallax is the most important depth cue for medium viewing distances.
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start learning
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Accommodation is the tension of the muscle that changes the focal length of the lens of eye. Thus it brings into focus objects at different distances
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start learning
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If we close one of our eyes, we can perceive depth by moving our head. This happens because human visual system can extract depth information in two similar images sensed after each other, in the same way it can combine two images from different eyes.
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