Open Inventor modules
Introduction
In total, there are three types of modules:
- blue ML modules
- brown macro modules
- green Open Inventor modules
The names of Open Inventor modules start with the prefix So\* (for Scene Objects). Open Inventor modules process and render 3D scene objects and enable image interactions. Scene objects are transmitted using the semi-circle shaped input and output connectors. With the help of these modules, Open Inventor scenes can be implemented.
An exemplary Open Inventor scene will be implemented in the following paragraph.
Open Inventor Scenes and Execution of Scene Graphs
Inventor scenes are organized in structures called scene graphs. A scene graph is made up of nodes, which represent 3D objects to be drawn, properties of the 3D objects, nodes that combine other nodes and are used for hierarchical grouping, and others (cameras, lights, etc.). These nodes are accordingly called shape nodes, property nodes, group nodes and so on. Each node contains one or more pieces of information stored in fields. For example, the Sphere node contains only its radius, stored in its radius field. Open Inventor modules function as Inventor nodes, so they may have input connectors to add Inventor child nodes (modules) and output connectors to link themselves to Inventor parent nodes (modules).
SoGroup and SoSeparator
The SoGroup and SoSeparator modules can be used as containers for child nodes. They both allow multiple inputs and combine the results in one single output as seen above. Nevertheless, there is a big difference in handling the traversal state of the scene graph.
In the network above, we render four SoCone objects. The left side uses the SoSeparator modules, the right side uses the SoGroup ones. There is a SoMaterial module defining one of the left cone objects to be yellow. As you can see, the SoMaterial module is only applied to that cone, the other left cone remains in its default grey color, because the SoSeparator module isolates the separator’s children from the rest of the scene graph.
On the right side, we are using SoGroup (
SoGroup module reference
). The material of the cone is set to red. As the SoGroup module does not alter the traversal state in any way, the second cone in this group is also red.
SoSeparator modules are the cause.
Details on these can be found in the
SoSeparator module referenceMore Information about Open Inventor and Scene Graphs can be found here , in the Open Inventor Overview or the Open Inventor Reference.