A vector mask creates a transparency effect based on a style of gradient ink, such as radial or rectangular. You can choose the style when you apply a vector mask, or you can apply an existing vector object as a vector mask.
A vector mask can be applied to any type of objects, including vector, paint, text, and group objects.
It’s easy to apply vector masks. You can drag a vector transparency tool to apply radial, directional, elliptical, or rectangular style masks. If you want to use precise values for position and transparency levels, you can enter numbers in the Transparency palette. You can apply a mask quickly by selecting an object and choosing Object | SpriteLayers and selecting a vector mask style in the submenu.
Vector mask styles
(Left to right) Radial, Directional, Rectangular, Elliptical
The styles of vector masks applied by the Vector Transparency tools are related to vector gradient styles. You can think of these tools as applying a hidden gradient to a masked object. The transparency effect is based on the hidden gradient; the transparency level is relative to the lightness of the gradient shading.
For example, a linear vector gradient blends colors along a straight axis. A directional vector mask fades from opaque to transparent along a linear axis. For linear vector gradients and directional vector masks, you can specify the length and angle of the axis.
The relationship between vector gradients and vector transparency masks can be seen if you detach a vector transparency mask. With a masked object selected, choose Object | SpriteLayers | Detach Mask. Canvas X Draw removes the vector mask and places it in the document as a separate vector object. If you examine this object, you see that it has a vector gradient. The gradient style is similar to the vector mask style. The vector gradient fades from black to white in the same way that the vector mask caused the masked object to fade from transparent to opaque.
The relationship between vector masks and vector gradients also works in reverse; use a vector gradient-filled object as a vector mask. (See Masking with a Vector Object.)
A vector mask is related to a vector gradient. If you detach a vector mask, you get an object with a gradient. The grays in the gradient correspond to transparency levels in a masked object.
The Vector Transparency tools provide the easiest way to create transparency effects, such as vignettes, (images that appear in ovals and other shapes), as well as linear, radial, or rectangular fades.
You can use the Transparency palette to apply vector transparency effects. When you use the Transparency palette, you can specify values for the position and intensity of the effect.
In the Transparency palette, the Mask menu shows the vector mask style when a selected object has a vector mask.
As you drag, a vector line or shape appears, which represents the position of the vector transparency effect.
You can use the Transparency palette to apply a vector mask. To open the Transparency palette, see Using the Transparency Palette.
You can’t select Object in the menu. To use an object as a vector mask, see Masking with a Vector Object.
When you apply a vector mask to a vector object, the mask affects the vector object’s fill ink or its fill ink and stroke (pen ink). To change the effect, change the Scope option in the Properties bar or Transparency palette. (See Controlling the Scope of Transparency Effects.)
Create a vector mask by attaching a vector object to another object. Like other vector masks, a vector mask created from a vector object produces transparency relative to its color values; e.g., if the vector object that you attach is solid white, it creates no transparency; if it is solid black, it creates 100% transparency, making the masked object invisible.
If the vector object and the object to be masked aren’t the same size, Canvas X Draw scales the vector object to fit the masked object.
You can edit vector masks that have been applied with the Vector Transparency tools, and masks created by attaching gradient-filled vector objects. Editing lets you change the boundary of the opaque and transparent areas of a mask. You can also add nodes for finer control of transparency levels.
The handles correspond to the values in the Mask area in the Transparency palette. When you drag a handle, the values are updated to match the new position.
Change values in the Transparency palette to make precise changes to a vector mask. When you change the mask settings, Canvas X Draw updates the mask handles to match the current position values.
The default handles that appear in Vector Mask Edit mode indicate the start and end points of the transparency gradient. For a directional mask (the most basic style), a hollow handle represents the point of 100% transparency, and the solid handle represents the point of 100% opacity.
When a vector mask is in Edit mode, you can add nodes to set additional opacity levels. The default mask has a start and end point, with a smooth transition from opacity to transparency between the start and end point. When you add nodes, set the opacity level at each node.
Nodes (small circles) let you set several opacity levels in a directional vector mask
Use the pop-up opacity slider to set the opacity level of a node. You can add a series of nodes for additional control of a transparency mask.
Setting node opacity
When you edit rectangular or elliptical vector mask styles, add nodes to the horizontal vector that joins the inner box, (which represents the area of 100% opacity), to the object’s bounding box. When you edit radial mask styles, you can add nodes to the circle, which represents the 360° sweep of the mask.
Removing a vector mask from an object removes the transparency effect produced by the mask.
When you detach a vector mask, the former mask appears in the document as a separate vector object filled with a grayscale gradient.
In Paint Edit mode, a temporary channel mask that represents the object’s vector mask appears in the Channel Mask slot in the Channels palette. The temporary mask lets you see the effect of the vector mask as you edit the paint object.
If you click in the Channel Mask slot to try to select the temporary channel mask for editing, Canvas X Draw asks if you want to convert the vector mask to a channel mask.
All objects—vector objects, text objects, paint objects, and group objects—have transfer modes, which are like invisible filters that affect the appearance of colors. When objects overlap, the transfer mode of the front object can change the appearance of the back object.
Transfer modes work with transparency effects, including opacity and transparency masks; however, transfer modes can make objects appear to be transparent without reduced opacity or transparency masks; e.g., Multiply mode lets underlying colors show through an object. The default transfer mode is Normal; i.e., the colors of overlapping objects do not mix unless the front object is partially transparent.
In addition to interacting with background objects, transfer modes can interact with the document’s white background. When an object’s transfer mode is Screen, anything white replaces the object’s color, so the document’s white background can make the object seem to be invisible.
For vector objects, apply transfer modes to fill inks alone or to fill inks and strokes together.
The following descriptions are based on objects with RGB colors with no other transparency effects. Each mode is described in terms of the front object when the back object’s transfer mode is Normal.
Canvas X Draw calculates transfer mode effects by applying formulas to color values. Canvas X Draw performs these calculations using RGB color values or CMYK color values.
For example, the formula for Multiply mode is Color 1 multiplied by Color 2. Canvas X Draw applies the formula separately to each value that defines a color. In the case of RGB colors, Canvas X Draw applies the formula separately to the red, green, and blue values. For CMYK colors, Canvas X Draw calculates the effect on cyan, magenta, yellow, and black values.
The significance of the color space calculation is that the effect you see on screen could appear completely different if the effect is printed in a different color space.
In particular, you must display transfer mode effects in CMYK if the document will be separated for printing with process (CMYK) colors. Otherwise, the color separations could produce colors that are completely different from the colors you see on screen.
For an example of this effect, draw several overlapping objects with different colors. Set the transfer mode of the front object to Difference. (See Available Transfer Modes.) Choose Layout | Display Options. In the Display Options manager, change the Mode from RGB to CMYK. Click OK to close the manager. To refresh the screen, press F5. You will probably see a significant change in colors when you switch from RGB to CMYK mode.
Select Grayscale from the menu to lessen the required memory if working on complex graphics or editing images. In Grayscale mode, your screen redraws faster than in CMYK or RGB.