# PreviewLayer enum

Namespace: [Grasshopper2.UI.Crystallography](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.ui.crystallography.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
[Flags]
public enum PreviewLayer
```

Enumerates all layers of a material preview thumbnail. This includes both bitmap and geometric layers.

## Values

| Name | Value | Description |
| --- | --- | --- |
| None | 0 | Includes no layers. |
| ShapeDiffuse | 1 | Diffuse colour adjusted for transparency and lighting. |
| ShapeShine | 2 | Highlight effects. |
| ShapeEmission | 4 | Emission effects. |
| AllShapeLayers | 7 | Includes all shape bitmap layers. |
| ContextColours | 512 | Pixel layer which determines the colour of the context at each pixel. |
| ContextDirect | 1024 | Pixel greyscale layer which sets the amount of darkening the context receives from fully opaque preview geometry. |
| ContextIndirect | 2048 | Pixel greyscale layer which sets the amount of brightening the context receives from fully opaque preview geometry. |
| AllContextLayers | 3584 | Includes all shape bitmap layers. |
| AllBitmapLayers | 3591 | Includes all shape and context bitmap layers. |
| SilhouetteEdges | 65536 | Vector layer containing a collection of silhouette edges. |
| VisibleEdges | 131072 | Vector layer containing a collection of visible edges. |
| HiddenEdges | 262144 | Vector layer containing a collection of hidden edges. |
| AllEdgeLayers | 458752 | Includes all edge layers. |
| All | 462343 | Includes all layers. |