PhotoSketch offers the following intuitive three-step workflow. A full description is available in the user manual.

The camera calibration module is first invoked to solve for intrinsic parameters of the camera such as focal length, center of projection, and radial lens distortion.

The camera pose recovery module then operates on an overlapping set of images of the scene to be modeled. The goal of this module is to automatically determine the position and orientation (pose) of the camera for each input image. The up-axis of the recovered poses must then be aligned to the up-axis of the SketchUp coordinate system.

The photo-guided modeling phase uses our drawing and modeling tools, along with the native SketchUp tools, to build the 3D model from photographs. This process begins by drawing 2D sketches of footprints or rooftops directly on the photos. This establishes the base of the 3D volumes, which will be created by extruding these footprints. The images projected from the known camera poses serve as guiding visual cues during sketching, extrusion, and tapering.