Height-field construction using cross contours.

•A novel method to construct a height field using cross contours: Our system uses cross contours as a metaphor for constructing a height field from a 2D hand-drawn input. Users can draw sketches without hard constraints or additional understanding about drawing primitives.•Unprojection of 2D polygons into 3D space based on properties of polygons: we consider intersecting cross contours as the projection of a 3D polygonal mesh approximating a depicted shape. We also propose an image-space optimization method to obtain 3D edge vectors and 3D normals of the polygons.•Height field construction without fixed boundary conditions: Instead of giving specific values as constraints, we constraint the relative height values between the intersection points of cross contours.