Separation and Layers
Separation is tightly dependent on SketchUp's Layers functionality. Layers are covered in full in SketchUp's own documentation; a summary is provided here as well as how layers relate to the separation task.
Overview of Layers
Layers in SketchUp are conceptually similar to the layers features of many common image-manipulation applications: they ofter the user a means of attaching labels to different parts of the model. These labels typically have some type of meaning to the model's creator and viewers, but not to SketchUp itself. For example, an architect that is designing a new building might want to create an "Existing Cityscape" for the currently-existing buildings in the target area, and a "New Building" Layer for the building that's being designed. This type of conceptual division often helps break up a model into easier-to-manage pieces.
SketchUp natively provides some tools for visualising Layers. These are accessible by selecting the Windows → Layers sub-menu item from the SketchUp main menu. This opens a dialog box similar to that shown in the following example.
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Clicking on any of the checkboxes will make that Layer visible or invisible. Clicking on the arrow in the top-right corner and selecting "Color by layer" will color-code all geometry according to the Layer it's on, determined by the little color-swatches.
Layers and the Virtualwind Plugin
The Virtualwind SketchUp Plugin uses SketchUp's Layers to separate geometry. By using the various Plugin Tools, five "Virtualwind Layers" will automatically be created:
- vwPlugin_Solids: Holds "Solid" geometry (Buildings)
- vwPlugin_Canopies: Holds "Canopy" geometry
- vwPlugin_Terrain: Holds "Terrain" geometry
- vwPlugin_Images: Holds SketchUp "Image" Entities. These are currently ignored by the Virtualwind Plugin, but may be supported in future versions.
- vwPlugin_Unhandled: Holds all remaining geometry that is not currently supported by Virtualwind.
When a SketchUp model is fully separated for export into Virtualwind, it might look similar to that shown in the following example.
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The next two topics will explore how to use the Separation-related Plugin Tools: the Make Terrain Tool and the Separate Solids and Canopies Tool.