Work with Faceted Topology
Faceted topology are surfaces that were broken down into groups of small polygons (basically triangles). This process is called meshing.
Types of Faceted Topologies
There are several types of faceted topology objects in ODA BimRv SDK. Each type has four different parameters:
- Max points — Defines the size of the point container.
- Precision — Defines the size of the precision values.
- Presence of offset — Object's offset.
- Flags — Additional object flags.
The following table shows the faceted topology differences:
| Type | Max points | Precision | Offset | Edge visibility flags |
|---|---|---|---|---|
| FacetedTopology0 | 64K | Single | - | - |
| FacetedTopology1 | 4M | Single | - | - |
| FacetedTopology2 | 64K | Single | + | - |
| FacetedTopology3 | 4M | Single | + | - |
| FacetedTopology4 | 64K | Double | - | - |
| FacetedTopology5 | 4M | Double | - | - |
| FacetedTopology8 | 64K | Single | - | + |
| FacetedTopology9 | 4M | Single | - | + |
| FacetedTopology10 | 64K | Single | + | + |
| FacetedTopology11 | 4M | Single | + | + |
| FacetedTopology12 | 64K | Double | - | + |
| FacetedTopology13 | 4M | Double | - | + |
As you can see, there are pros and cons to these types of faceted topologies:
- Max points — A container for faceted topologies with 4M points occupies more memory, but it can represent a more detailed model (up to 4 million points can be used).
- Precision — A container with double precision values ("double") is more precise, but takes two times the memory than single-precision ("float"); 8 bytes instead of 4 bytes for each point.
- Offset — An additional 3D-based value gives the ability to add the object's offset, but it allocates more memory.
- Edges visibility flags — More memory is needed for these flags, but it gives additional advantages in special cases.