Solid Geometry
HyperMesh provides tools to create and edit solid geometry. In this section we will learn about solid topology, how to create a solid from enclosed surfaces, how to edit a solid, and finally what the term mappable means and how to make a solid mappable.
Expand the sections below to learn more about Solid Geometry in HyperMesh.
To use the automatic Solid Map function the geometry must be split into mappable shapes. Mappable shapes are defined as 2 opposing faces (source and destination) and faces that directly connect the source and destination (along faces).
While this example shows two faces that are of the same shape and directly oppose each other, that is not a requirement. The source and destination can be of drastically different shape and contour and need not lie directly opposite each other.
Requirements and Tips
- Shape must be a closed volume
- Multiple source faces are allowed
- Destination face must be a single face
- No edges are permitted that are perpendicular to the drag direction. If they exist they must be suppressed.
The first step is to create a solid. This is done with the Solids panel, Bounding Surfaces subpanel. This can be accessed through the main menu by selecting Geometry > Create > Solids > Bounding Surfaces. Below is the Solids panel with the Bounding Surfaces subpanel. Use your mouse and roll over the different options in the subpanel for a description of each option.
Because the surfaces enclose a single volume, a solid can be created. Activating Auto select solid surfaces allows us to select only one surface and HyperMesh will select the remaining surfaces that enclose the volume. Once create is selected, a solid is created. Below is an illustration of the surfaces (grey with green lines) and then what the geometry looks like as a solid entity (green with green lines):
In this section we will explore some of the tools needed to make a solid mappable. Many of these tools are the same ones we used in Chapter 1, but here we will see how they work with a different model.
Before we start looking at the various tools available in HyperMesh to split the solid to make it mappable, let's first fully understand how the Mappable view in HyperMesh works. Within the Visualization toolbar there is an option for the Mappable view:
When this view is selected, the solid faces are colored by their mappability. Any given volume can have one of four states, which are color-coded when using the mappable view option on the visualization toolbar. Although the colors can be customized, the default settings are:
- Blue indicates a solid that has not been edited at all and therefore isn't evaluated for mappability.
- Orange indicates a solid that has been edited, but remains completely unmappable (further partitioning may enable mapping).
- Green indicates a solid that is mappable in three directions (this is very rare).
In the image above, the left cube is mappable in 3 directions. But if that cube has one corner split off (right cube), it becomes mappable in only 1 direction and the corner is not mappable without further partitioning.
Returning to our model, in order to make the solid mappable, several partitions need to be made. Most of these partitions can be made using the Solid Edit panel, split with plane/surf subpanel. The with surfs option will be used and the panel is shown below:
In the image below, surfaces are selected one at a time to trim the solid. A total of 5 surfaces are selected to trim the solid:
Now that the solid has been split using the surfaces, the view is changed to the Mappable View (as shown below). Notice how all the solids are now mappable in 1 direction except for a single solid.
In order to make the remaining solid mappable, some topology editing needs to be done. This is done using the Quick Edit panel. This panel will be discussed in more detail in the next sections. The tool that will be used to edit the remaining solid is the split surf-line tool. Using this tool, a face in the solid is split by selecting a node and then a line:
Once the face is split, the solid can be split using the Solid Edit panel, trim with lines subpanel. The with bounding lines option is used and the two lines shown below are selected to split the solid:
Returning the view to the Mappable view, we now see that all solids are mappable in 1 direction. We are now ready to create the solid mesh:
Once a solid is split and is considered mappable, you can still do some topology revision. This topology revision can help give the user more control over the node seeding when the solid meshing is done. To do the topology revision, the Quick Edit panel can be used. This panel is accessed by selecting Geometry > Quick Edit
Once the topology revision is complete, meshing can be done. The solid hexa mesh is created using the Solid Map panel (this panel was covered in detail in the previous chapter). The multi solids subpanel is used to mesh multiple solids in a single step. In the example below, two solids are selected and then the mesh is created. The interactive option is used and the node seedings are edited before the solid mesh is created. Notice how the area where the topology revision was done is used to edit the node seeding. This process is repeated a few times to complete the solid mesh:
