A single experiment is reported that measured the apparent stereoscopic shapes of symmetric and asymmetric objects at different viewing distances. The symmetric stimuli were specifically designed to satisfy the minimal conditions for computing veridical shape from symmetry. That is to say, they depicted complex, bilaterally symmetric, plane-faced polyhedra whose symmetry planes were oriented at an angle of 45° relative to the line of sight. The asymmetric stimuli were distorted versions of the symmetric ones in which the 3D position of each vertex was randomly displaced. Prior theoretical analyses have shown that it is mathematically possible to compute the 3D shapes of symmetric stimuli under these conditions, but those algorithms are useless for asymmetric objects. The results revealed that the apparent shapes of both types of objects were expanded or compressed in depth as a function of viewing distance, in exactly the same way as has been reported in many other studies, and that the presence or absence of symmetry had no detectable effect on performance.

据报道，一项实验测量了对称和不对称物体在不同观看距离下的表观立体形状。对称刺激经过专门设计，以满足根据对称性计算真实形状的最低条件。也就是说，他们描绘了复杂的、双边对称的平面多面体，其对称面与视线成 45° 角。非对称刺激是对称刺激的扭曲版本，其中每个顶点的 3D 位置是随机移位的。先前的理论分析表明，在这些条件下计算对称刺激的 3D 形状在数学上是可能的，但这些算法对于不对称物体毫无用处。结果表明，两种类型物体的外观形状都会随着观看距离的变化而在深度上扩展或压缩，这与许多其他研究中报道的方式完全相同，并且对称性的存在或不存在无法检测到。对性能的影响。