Inverting the mask

About mask modes

Editing a mask

The mask looks pretty good, but instead of masking the information inside the monitor, the mask has removed everything outside the monitor. So you need to invert the mask. (Alternatively, you could change the mask mode, which is set to Add by default.)

Blending modes for masks (mask modes) control how masks within a layer interact with one another. By default, all masks are set to Add, which combines the transparency values of any masks that overlap on the same layer. You can apply one mode to each mask, but you cannot change a mask’s mode over time.

The first mask you create interacts with the layer’s alpha channel. If that channel doesn’t define the entire image as opaque, then the mask interacts with the layer frame. Each additional mask that you create interacts with masks located above it in the Timeline panel. The results of mask modes vary depending on the modes set for the masks in the same layer. Using mask modes, you can create complex mask shapes with multiple transparent areas. For example, you can set a mask mode that combines two masks and sets the opaque area to the areas where the two masks intersect.

For this project, you need everything inside the mask to be transparent and everything outside the mask to be opaque. You’ll invert the mask now.

1 Select the office_mask layer in the Timeline panel, and press the M key to see the Mask Path property for the mask.

_ Tip: Pressing the M key twice in quick succession displays all mask properties for the selected layer.

There are two ways to invert this mask: by choosing Subtract from the Mask Mode pop-up menu, or by selecting the Inverted option.

2 Select the Inverted option for Mask 1. The mask inverts.

3 Press F2, or click an empty area of the Timeline panel, to deselect the office_ mask layer.

If you look closely at the monitor, you will probably see portions of the screen still appearing around the edges of the mask.

These errors will certainly call attention to changes being made to the layer, and they need to be fixed. To fix them, you’ll change the straight lines to curves.

Дата добавления: 2014-11-20