Model 3D construction application program interface

摘要

An application program interface may be used to construct a three-dimensional (3D) scene of 3D models defined by model 3D objects. The interface has one or more group objects and one or more leaf objects. The group objects contain or collect other group objects and/or leaf objects. The leaf objects may be drawing objects or an illumination object. The group objects may have transform operations to transform objects collected in their group. The drawing objects define instructions to draw 3D models of the 3D scene or instructions to draw 2D images on the 3D models. The illumination object defines the light type and direction illuminating the 3D models in the 3D scene. A method processes a tree hierarchy of computer program objects constructed with objects of the application program interface. The method traverses branches of a 3D scene tree hierarchy of objects to process group objects and leaf objects. The method detects whether the next unprocessed object is a group object of a leaf object. If it is a leaf object, the method detects whether the leaf object is a light object or a drawing 3D object. If the leaf object is a light object, the illumination of the 3D scene is set. If a drawing 3D object is detected, a 3D model is drawn as illuminated by the illumination. The method may also performs a group operation on the group of objects collected by a group object.