3D Compositing with Action > Action: Masks >
Creating a Mask

After you have added a GMask object to the scene, you can now create the mask itself.

To create a mask:

1. In the Edit Modes box, select Create (N).
2. Do any of the following as draw the mask:
   - Click to add vertices.
   - Shift-click to hide vertices and tangents as you add them.
   - Shift-drag to draw the mask freehand. Vertices and tangents are hidden as you add them. After closing the mask, you can use the Lasso Fit field (in the Vertices tab of the GMask menu) to increase or decrease the number of vertices that define the freehand segments of the mask.
   - Click and drag out the tangents to adjust the curvature of the spline at the current vertex.
3. Complete the mask by closing the mask shape or leaving it as an open spline. See Closing the Mask and Finishing the Mask.

#### Topics in this section

- Editing the Mask
- Closing the Mask
- Finishing the Mask