To Create a Surface Mask

1. In Toolspace, on the Prospector tab, expand the surface collection, right-click Masks, and click Create Mask.
2. From the drawing, select an object or multiple objects to define the mask. Press Enter.
3. In the Create Mask dialog box, in the properties grid, click the Value column for the Name property and enter a name for the mask.
4. Click the Value column for the Description property and enter a description for the mask.
5. For Mask Type property, select Inside or Outside.
   Note: If you define an inside mask on a surface, you cannot create another inside or outside mask on the same surface.
6. Depending on whether or not you want to set a selected object as a render-only mask, select Yes or No for Render Only option.
   Note: If multiple objects are selected for the mask, the Render Only option is set to true and is unavailable.
7. Optionally, if the polygon object from which you are creating a mask has curves, enter a value in the Mid-Ordinate Distance field or click to digitize a distance in the drawing area.
8. Specify the render material by clicking in the Render Material row and clicking .

   The Render Material dialog box is displayed. For more information, see To Work With Render Materials.

9. Click OK.

   The mask is created and added to the surface Masks collection in the Prospector tree.

   Note: A render-only mask must be rendered before it is displayed.