- Sep 23, 2008
Understanding Vanishing Point and Perspective Angle
Objects in 3D space represented on a 2D surface (such as the computer screen) are rendered with perspective to make them appear as they do in real life. Correct perspective depends on many factors, including the vanishing point and the perspective angle, both of which can be changed in Flash.
The vanishing point determines where on the horizon parallel lines of a perspective drawing converge. Think of railroad tracks and how the parallel tracks seem to converge to a single point as they recede into the distance. The vanishing point is usually at eye level in the center of your field of view, so the default settings are exactly in the middle of the Stage. You can change the vanishing point setting, however, so it appears above or below eye level, or to the right or left.
The perspective angle determines how quickly parallel lines converge to the vanishing point. The greater the angle, the quicker the convergence, and therefore the more severe and distorted the illustration appears.
Let's experiment with these perspectives:
- Select an object on the Stage that has been moved or rotated in 3D space.
- In the Property inspector, expand the 3D Position and View section, as shown in Figure 12.
- Click-and-drag the X and Y values of the Vanishing Point setting (set to 300 and 225.0, respectively, in Figure 12) to change the vanishing point, which is indicated on the Stage by intersecting gray lines (see Figure 13).
- To reset the vanishing point to the default values (to the center of the Stage), click the Reset button.
- Click-and-drag the Perspective Angle value (set to 55.0 in Figure 12) to change the amount of distortion. The greater the angle, the more the distortion, as shown in Figure 14.