Graphics Programs Reference
In-Depth Information
The Orthographic Scale zoom discards the vanishing point concept. When
you zoom in and out with the camera, only the object scale appears to be
changing with the camera view.
When you drag with the 3D Camera Zoom tool over the object with the
Orthographic Scale mode, you change the scale of the object, which is
calculated based in part on the object size. For example, the view of the
object can be 1/10 of the object size, which is larger than 1/50 of the object
size. So an object with the value 1/50 looks farther away than the same
object with a scale of 1/10.
When the Orthographic Scale value is 1/1, the camera is in the middle of the
object, so the object does not appear on the screen.
In the following exercise, you will see the diference between the Perspective
camera view and the Orthographic Scale zoom:
1. Open the ile 3Dspace_ship.psd, which includes a 3D spaceship model.
2. Click the 3D Camera tool or press the N shortcut to activate it.
3. Choose the 3D Camera Zoom tool from the Properties toolbar.
4. Make sure that the Perspective view is selected.
5. Choose the 3D Object Rotate tool or press the K key as a shortcut.
6. Start dragging the object to rotate it and see how the object's sides
maintain the vanishing point based on the distance of the camera.
7. Click the Orthographic Scale Zoom icon.
8. Click the 3D Object Rotate tool.
9. Click and drag over the object and notice that the object is not afected
by the vanishing point (Figure 10.6).
Figure 10.6
The spaceship on the
right is using the Orthographic Scale
Zoom. Notice that it doesn't look
quite right, as it does not consider the
perspective of the object. The
spaceship on the left is using the
Perspective camera view. However, it
appears correct considering the
perspective of the object.
