Overview

This section reviews how to design scene-graphs for a variety of application types, and assumes familiarity with the database concepts located in HOOPS/3dGS Programming Guide Section 1.0. When creating your scene-graph, you should always follow general segment and geometry organization guidelines reviewed in Section 7.1 and Section 7.2 of the guide.

All of the guides depict a scene graph that is created underneath a main 'model' segment, which would then be included by one or more 'views'. If you are using HOOPS/MVO, this starting segment hierarchy is implicitly created when instantiating the HOOPS/MVO HBaseModel and HBaseView objects, and you would create the model underneath the prexisting 'model' segment. If you are not using HOOPS/MVO, you will need to manually create this view/model segment hierarchy.

HOOPS/MVO also has built-in support for exporting/importing the model data to/from several file formats. However, you may not by using MVO, or may need to write your own custom logic for model export/import. In either case, you should export the scene-graph starting with the contents of the 'model' segment, and likewise import a scene-graph into the 'model' segment.

 

AEC/GIS/ECAD

This describes the scene-graph that would typically be created by applications in the AEC, ECAD, and GIS markets. These application types commonly deal with 2D information distributed among various layers, which need to be independently manipulated, ordered, and styled.
 

3D/MCAD

This describes the scene-graph that would typically be created by MCAD, 3D Viewing or 'generic' 3D applications. It discusses how to represent assembly, part, body, and edge topology, and also reviews efficient segment organization for 3D data.
 

2D/3D

This describes a scene-graph whose 3D model is based on the 3D/MCAD scene-graph discussed above, but incorporates concepts required by 'design intent' applications in the CAD market. These are applications that contain 3D part data, but also overlay 2D annotation data on the 3D objects, and layout multiple views of the model in preparation for hardcopy.
 

CAE

This describes the scene graph common to Computer Aided Engineering applications. These include Finite Element Analysis (FEA) and virtual prototyping/simulation applications. It reviews concepts such as creating legend bars, applying color ramps to the model, and using the various face/edge visibility capabilties available in HOOPS/3dGS. (This document focuses on the post-processor component of these applications. You should refer to the 3D/MCAD document above if you're designing a scene-graph for a pre-processor.)