You can create an Opacity channel for paint layers that lets you paint a transparent effect on a mesh, useful for simulating transparent real-world materials like glass and ice.

- In the Layers window, switch to the Paint tab and click
to create a new paint layer.
- In the Create New Paint Layer window that appears, set the Channel to Opacity.
- Select a paint tool from the Paint Tools tray, then set the tool Color to black. Note: Painting with darker colors makes areas on a model more transparent, while painting with lighter colors make the areas more opaque. Paint with black for complete transparency, and paint with white for complete opacity.
- Stroke to paint the areas you want to make transparent.
Areas that you paint now appear with a glass-like transparent effect.
Tip:To change the transparency effect from the default glass-like appearance to a more cut-away effect, change the Opacity Affects property of the material from Diffuse Only to All Channels. To open the material properties, right-click the model in the scene and select Edit Material from the pop-up menu that appears.