Creating a rounded rectangle mask in After Effects is straightforward and can be achieved in a few simple steps. There's no direct "roundness" slider for masks, but you can utilize the built-in shape tools and their properties to achieve the desired effect.
Methods for Creating Rounded Rectangle Masks
Here are two primary ways to create rounded rectangle masks in After Effects:
1. Using the Rounded Rectangle Tool:
- This is the most intuitive approach.
- Select the Rounded Rectangle tool from the Tool panel.
- Click and drag on your composition to create the rounded rectangle.
- The corner radius is adjustable during the creation process. Use the arrow keys on your keyboard to subtly increase or decrease the radius while still dragging to draw the shape. You cannot adjust the radius after the shape is created.
- This shape automatically creates a mask if it's applied to a layer. You can modify this mask further.
2. Using the Rectangle Tool and Modifying the Path:
- If you need more precise control or are making adjustments after initial creation, use the Rectangle tool.
- Create a rectangle mask or shape layer.
- Select the Convert Vertex Tool (freehand selection tool).
- Click on the corner points of your rectangle.
- Drag the corner points to round the corners to your desired level of curvature.
- Manually adjusting these points offers flexibility for asymmetric rounding.
Additional Tips and Considerations
- Shape Layers: Creating a shape layer (a rounded rectangle in this case) is different from creating a mask. A mask affects a layer's visibility, while a shape layer is an independent element in the composition. While they produce the same visual result often, using shape layers is preferable for animation and effects.
- Pre-Compositions: If you're working with complex compositions, creating a pre-composition with your rounded rectangle mask can streamline the workflow and maintain organization.
Remember that the ability to adjust the roundness of a mask’s corners directly after creation is not available. You need to create the rounded rectangle either during drawing or by manually adjusting its vertices post-creation.
