Classes

The Entity class provides a local coordinate system (LCS) and is a container for child Entities objects. An Entity object can have any number of child nodes. It acts as a base class for three further specialised classes. The resulting entity tree is the scene graph. Many scene graphs at the same time are allowed. An entity object can be embedded only into one scene graph at the same time.

A Frame is a visible which provides a view port to the scene. It contains a reference to an Entity object which acts as the camera. This camera entity is part of the entity tree which becomes to be rendered. A Frame holds further the rendering policy for special effects like fogging, blending, texturing, lighting and so on.

The Light class provides a dynamic light source. That means that by transformations (rotation, scale, or translation) the light effect on surfaces changes. Static light sources are already contained in the lighting information of 3D shapes (i.e. intensity of verticies or intensity maps). The source of the light is always the centre of the local coordinate system. The direction belongs to the negative z-axis

A Sensor is a sensitive area to check whether an object moves or rotates inside an area, whether Sensors are colliding or hit by the users pointing device. It has a primitive geometrical structure, it is either a sphere, a plane or a box. A Sensor can either have a volume or be volume-less.

The Shape class provides means for presenting 3D content data. It encapsulates the handling of primitive 3D-objects like triangles, quads, fans, stripes, textures etc.. It depends from content retrieval, engine and domain how many features of its handled format are transferred into the scene graph. On slow machines the engine may avoid texture mapping, blending or other features which can be omitted to increase rendering speed. The content retrieval of the current domain may use established Internet and ISO standards for 3D file formats like DXF, 3DS, VRML(X3D) etc.. Content data may include level of detail information, intensity maps etc., too.