Perceiving the shape of three-dimensional objects is essential for interacting with them in daily life. If objects are constructed from different materials, can the human visual system accurately estimate their three-dimensional shape? We varied the thickness, motion, opacity, and specularity of globally convex objects rendered in a photorealistic environment. These objects were presented under either dynamic or static viewing condition. Observers rated the overall convexity of these objects along the depth axis. Our results show that observers perceived solid transparent objects as flatter than the same objects rendered with opaque reflectance properties. Regional variation in local root-mean-square image contrast was shown to provide information that is predictive of perceived surface convexity.

感知三维物体的形状对于在日常生活中与它们互动至关重要。如果物体是由不同的材料构成的，人类视觉系统能否准确地估计它们的三维形状？我们改变了在真实感环境中渲染的全局凸物体的厚度、运动、不透明度和镜面反射度。这些物体在动态或静态观看条件下呈现。观察者对这些物体沿深度轴的整体凸度进行了评级。我们的结果表明，观察者认为固体透明物体比使用不透明反射特性渲染的相同物体更平坦。局部均方根图像对比度的区域变化可以提供预测感知表面凸度的信息。