Abstract: An image depicting an object has a center that is not on an optical axis of a camera used to capture the image. The image is on an image plane, and the object is in an object space. A method implemented for automatically determining the position of the camera relative to the object includes displaying the image via a user interface, receiving vanishing point information from the user interface, such that the vanishing point data indicates a respective location on the image plane of each of a first vanishing point, a second vanishing point, and a third vanishing point, and automatically determining the position of the camera based on the first vanishing point, the second vanishing point, and the third vanishing point.

Abstract: In a computer-implemented method of determining an outer shell of a composite three-dimensional model, an indication of a plurality of initial faces of the composite three-dimensional model is received. A plurality of intersections between the plurality of initial faces is determined. A plurality of split faces is generated by splitting each of the plurality of initial faces that intersects another one or more of the plurality of initial faces into two or more split faces along one or more lines of intersection. It is determined whether each of the plurality of split faces and each of the plurality of initial faces that does not intersect another one or more of the plurality of initial faces corresponds to the outer shell or to an interior portion of the composite three-dimensional model.

Abstract: A three-dimensional design and modeling environment allows users to draw the outlines, or perimeters, of objects in a two-dimensional manner, similar to pencil and paper, already familiar to them. The two-dimensional, planar faces created by a user can then be pushed and pulled by editing tools within the environment to easily and intuitively model three-dimensional volumes and geometries.