Patent attributes
An information processing apparatus acquires a plurality of geometric features and normals at the respective geometric features from a target object arranged at the first position. The information processing apparatus also acquires a plurality of normals corresponding to the respective geometric features of the target object from a shape model for the target object that is arranged at the second position different from the first position. The information processing apparatus calculates direction differences between the acquired normals for respective pairs of corresponding geometric features of the target object and shape model. The information processing apparatus determines whether or not occlusion occurs at each geometric feature by comparing the calculated direction differences with each other.