Blending and Masks
Use blending and clipping masks to render an irregular shape.
Rendering a Statue
Using a combination of blends, offset paths, and clipping masks, we’ll render a part of this logo illustration (based on a statue) for a conference in Vienna. The overall figure of the woman was first blocked in with basic objects. Looking at all the objects that need to be rendered can be a little intimidating, so we’ll concentrate on one part—the arm of the statue. Select the object that makes up the arm, and then press Cmd-Option (Ctrl-Alt)-Shift-3 to hide all the other objects on the artboard.
Create a Basic Mask
You’ll use what you learned earlier in this chapter and create a clipping mask using Offset Path to create a background shape for the mask. With the arm object still selected, choose Object > Path > Offset Path. In the dialog box that appears enter 2 pt and click OK A. With the new offset path still selected, hold down the Shift key and select the original shape too. Press Cmd (Ctrl)-7 (or choose Object > Clipping Mask > Make or bring up the contextual menu and choose Make Clipping Mask) to create a mask B.
Start to Create the Highlight Shape
Using the arm shape as the starting point, create a blend that defines the highlight of the arm. With the Direct Selection tool, select the left side anchor points of the arm shape (now being used as a clipping mask). Press Cmd (Ctrl)-C to copy the path segment, and then press Cmd (Ctrl)-F to paste the segment on top of the mask in the exact same location.
Finish Creating the Highlight Shape
Now move the path segment with the Selection tool to the point where the highlight will end. With the path segment still selected, press Cmd (Ctrl)-J to close the path. Use the Add Anchor Point tool to add three anchor points to the newly enclosed path A. Using the new anchor points, create a shape that extends past the arm B. Then fill the new shape with a highlight color. You’ll see that the highlight shape conforms to the contour of the arm and sits inside the clipping mask C.
Rule Breaker: The Shape Becomes Part of the Mask
Since the shape you just created was taken from a segment of the clipping mask and then pasted in front of that same clipping mask, based on the rule about masks always needing to be on the top layer in the stacking order, why did the highlight shape become part of the clipping mask? Unfortunately, explaining the inner workings of why masks work in this way is beyond the scope of this book or project. Suffice it to say that a) it works, and b) if you really need a detailed explanation of why it works, check out Mordy Golding’s Illustrator blog site at http://rwillustrator.blogspot.com/
2006/08/ask-mordy-you-gotta-read-between-lines.html where his mission in life is to explain Illustrator’s many unsolved mysteries.
Make the Starting Point of the Highlight
Now, back to the show . . . Select the highlight shape you just created and press Cmd (Ctrl)-C to copy the shape and then Cmd (Ctrl)-F to paste the copy in front of the original shape A. Using the Direct Selection tool, select the anchor points that make up the curve and move that portion of the curve to the starting point of the blend B. Fill the original highlight shape with the body color C.
Create the Blend
Create the blend of the two shadow shapes by selecting both shapes and then pressing Cmd-Option (Ctrl-Alt)-B (or choose Object > Blend > Make). The result is a blended shadow that conforms to the shape of the arm.