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.
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.
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.
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.
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.)