Abstract
We investigated the relationship between the texture in a local region and the global texture on a ground plane in a simulated 3-D scene in determining the judged distance between two objects. The displays consisted of a ground plane containing an irregularly shaped local region. Three vertical poles were located in this region, arranged in an inverted L so that poles 1 and 2 were separated in depth and poles 2 and 3 were separated horizontally. To enhance perceived depth, the displays translated horizontally and were viewed through a collimating lens. Subjects adjusted the distance between the two poles that were separated horizontally to match the perceived distance between the two poles that were separated in depth. In Exp. 1 and Exp. 2 either the local region or the background was textured and the other area was a uniform gray. We found in Exp. 1 that a regular stripe texture was equally effective as the local and global texture, whereas a random dot texture was effective only as the global texture. In Exp. 2 we varied the scale of the textures and found that the increase in the effectiveness of a dot texture as a global texture, rather than a local texture, was greater for smaller scale textures. In Exp. 3 both the background and the local region were textured, with one of four different textures—two regular and two random—used in each area. Judged distance was determined by the local texture with a local stripe texture (projecting to converging lines) most effective regardless of the global texture. Overall we found that with only the local or global region textured, some textures were effective both as local and global textures, whereas other textures were effective only as global textures. With both regions textured, judged distance was determined by the texture in the local region.