Computer Image Generation Texture Study

摘要

This development project resulted from the need to enhance visual flight simulators (based on computer image generation (CIG) techniques) with textured surfaces. Pilots viewing homogeneous surfaces experience an inadequate perception of motion above these surfaces as well as an ambiguity in the orientation of the surface. Therefore, it was felt that by using textured surfaces within the scene, both depth and motion cues would be made available. This report describes the approaches and techniques used to develop texture material and introduce it into a complex CIG scene. The approach is to create texture tile arrays of trees and grass from digitized photographs of natural texture. These arrays are then replicated over the surface in the fashion of tiles. Preprocessing techniques are described which eliminate the periodic effect due to the tile boundary and macropatterns within the tile itself. Level-of-detail texture tile arrays are created that match the resolution of the texture to the appropriate observer-scene viewing geometry. The level-of-detail arrays and other descriptive parameters are merged into the existing CIG software to produce textured images. Scenes depicting a landing sequence, a divebomb, and a low-altitude flight were then generated. These images show the effect of the varying levels of detail, fields of viewing geometries, and scene deriving distance and motion cues from the additional information contained in the textured images. (Author)