Revolving a Semicircle to Generate a Sphere
Now that we've touched on the conceptual dimension of 3D effects, and I've briefly introduced extrusion and revolving, let's bring on the main act—the 3D Revolve effect. In the rest of this article, I'll show you how to revolve a semicircle to generate a sphere, and then how to map a vector map of the earth onto that revolvable globe.
In this example, we'll create a circle, cut it in half to create a semicircle, and then revolve the semicircle into a sphere. Let's get started:
the Ellipse tool, hold down the Shift key, and click and drag to create a
circle. (Holding down Shift as you drag constrains the ellipse to a perfect
circle.) Use the Direct Selection key to select the left anchor in the circle
(see Figure 4).
Figure 4 Starting with a perfect circle.
- Press the Delete key to delete the left anchor, leaving a semicircle. Apply a thin black stroke and no fill to the semicircle (you can select these attributes from the control panel).
- With the semicircle selected, choose Effect > 3D > Revolve to open the 3D Revolve Options dialog.
- Click the More Options button in the 3D Revolve Options dialog. From the Surface pop-up, choose Wireframe. You'll be applying a map to the surface of the sphere, but for now the wireframe helps give a sense of the 3D generated effect.
- Choose either the left edge or the right edge from the From pop-up. (Enabling the Preview checkbox will reveal the different effect generated by starting from either the right or left edge.)
the Revolve area of the dialog, set the Angle to the default value of 360
degrees to generate a fully revolved object (see Figure
Figure 5 A generated 3D sphere.
- Play with the rotation of the sphere: Click and drag on the cube to define all three axes: x (horizontal), y (vertical), and z (front to back).
- When you have finished defining the 3D Revolve effect, click OK.