User's Guide

Virtualwind SketchUp Plugin Tools   →   Exporting to Virtualwind   →   Exporting and Groups

Exporting and Groups

The export process is heavily dependent on the presence of SketchUp Groups. Only geometries that are contained within at least one SketchUp Group are exported: any "top-level geometry" – that is to say, geometry that doesn't belong to any SketchUp Group – will always be ignored.

This leads to an important observation: Exporting a model that has no Groups in it will produce an empty VWS file (i.e. a VWS that has no geometry in it). This is one of the two most common mistakes when trying to load a model into Virtualwind. The other is discussed in Separating Geometry. If you load a model that was exported but did not have any Groups in it, Virtualwind will look like it loaded "empty". Alternatively, you might find that part of the model is missing in Virtualwind. If this happens, check that all the geometry you want to contain is in Groups.

SketchUp Groups, Virtualwind Entities, and Virtualwind Parts

Each top-level SketchUp Group is exported as a Virtualwind Entity of some type – i.e. a Canopy, a Building, or a Terrain. The exact type of the Entity depends on the type of Export that is performed. This is discussed in the next section.

In contrast, Virtualwind Parts are determined by the "sub-Group" information. Any nested Group (in other words, any Group within a Group) is exported as a Part of that Entity. All geometry that is directly part of the Group (i.e. not contained in a sub-Group) will be collected into one extra Part. For example, if you have a Group on the Canopy layer that has three sub-Groups plus some extra geometry that is not in a sub-Group, that geometry will be exported as a Canopy Entity with four Canopy Parts – one Part for the "direct geometry", plus one Part each for the three sub-Groups.

Nested Groups, Flattened Parts

Although SketchUp supports "nested Groups", Virtualwind does not support "nested Parts". In other words, you can't have a Part within a Part in Virtualwind, even though you can have Groups within a Group in SketchUp.

The export process resolves this apparent mismatch by "flattening": all nested sub-Groups are converted into Parts and "promoted" to the top. To understand this concept better, you are encouraged to experiment with some models of your own.

The Quickest Way to Make a Group

Although covering the full functionality of Groups is beyond the scope of this User Guide (it is covered in detail in SketchUp's documentation), the quickest way to make a Group that contains all the geometry in a model is outlined below. This is useful if you just want the model in Virtualwind, but you do not necessarily care about its structure. To make a Group, follow these steps:

  1. Ensure that you are in the model's top level (in other words, make sure you're not editing a Group).
  2. Type ctrl-a. (This is the keyboard shortcut for "Select all".)
  3. Type 'g'. (This is the keyboard shortcut for "Make Group".)
  4. In the dialog box that appears, click on the "Create" button.