P‐24: Terrain Texture and 3‐D Object Cues in the Control of Heading in Simulated Flight

Abstract

The effects of terrain texture type and the height and density of 3D objects on heading control were studied in two experiments conducted in a high‐performance flight simulator. The results suggest an orthogonal‐extension principle which relates performance to the number and length of contours that are perpendicular to the ground plane, and also begin to define the stimulus conditions for which the principle is valid.

The role of visual occlusion in altitude maintenance during simulated flight.

“…Whereas there is no distinction between object height and object width in the occlusion model of Equations 1-3, these two variables may be expected to have different effects on motion perspective and hence on altitude-maintenance performance. The available experimental evidence suggests that motion-perspective cues are affected by vertically extended contours (Patterson et al, 2003) but not horizontally extended contours (Covas et al, 2005). In Experiment 2, we varied the radius (width) of 3-D objects in order to determine whether increasing horizontally extended oc-clusions affected altitude-maintenance performance differently than did the increase in vertically extended occlusions, which was tested in Experiment 1.…”

“…In the case of movement over a textured surface or a scene containing 3-D objects, the most salient perceptual cue is the motion gradient formed by differential movement of the texture elements or the 3-D objects (Sedgwick, 1986). This motion gradient is a visual cue that could be used for altitude maintenance (Patterson et al, 2003). Horizontal motion perspective has been shown to be used for lateral control, such as in the control of heading (see, e.g., Li & Warren, 2000;Longuet-Higgins & Prazdny, 1980;Rieger & Lawton, 1985), and there is some evidence that vertical motionperspective cues may also be used for altitude control (Covas et al, 2005).…”