virtual reality and texture mapping

"Texture mapping" is an efficient method to create surfaces for 3D virtual things by overlaying 2D texture gradients on object surfaces. Depth perception of these surfaces can be then be refined via the use of shading and reflected light. "Ray tracing" takes light reflection to a high level by tracing individual beams of light as they bounce among things and ultimately bounce from the exterior surfaces of objects to the viewer. Texture mapping, light shading, and ray tracing are computationally intensive, particularly for complex virtual constructs with moving things. Conveniently for the sake of computing cost, people do not follow as much vision detail in travelling things as in immobile things. Accordingly, computational effort in Virtual Reality can be reduced without serious reduction in perceptual realism by rendering the surfaces of travelling things in less detail than the exteriors of stationery things. See TwirlPix Digital Photography Services for interesting material.

One method to view different pictures on a screen far away is to have eyes view the screen with different polarized filters. This is the way "3D glasses" work in movies. The interaction of the polarized filters with colors or other attributes of the picture on the screen changes the pictures, causing different perspectives and depth perception, but this method has significant limitations. Another method to present the eyes with different pictures is to use "shutter glasses." Shutter glasses alternatively block the picture to one eye and then to the other, in synchronization with images from two different perspectives shown successively on a single screen. When the alternating images are shown in sufficiently quick order, then the brain integrates the two pictures into one three-dimensional image. Most Head Mounted Displays (HMDs) used in virtual reality are some type of helmet that includes: some type of shutter glasses; a relatively close high-resolution screen with an image that spans more than 60 degrees of the scope of vision and moves with head motion; and a mechanical, optical, magnetic or other mechanism to track head motion. Virtual Tours Grand Rapids, Minnesota discusses further information and sources.

In depth, Virtual Reality Maps .