Animating a Camera View Along a Path

Autofly lets you animate the camera view of a scene along a path to effectively simulate a walkthrough of a scene.

• Geometry in a scene cannot be animated using the Autofly function.

• The camera is animated to travel along any NURBS curve.

Overview

When animating the camera, think of the camera in terms of three component parts:

At least one curve is needed to use the Autofly function. If only one curve is used, that curve must be assigned as the motion path for the camera eye. The camera view then remains directly in front of the camera at all times throughout the animation. In some applications, this may be exactly what you want. In other applications, you may want to control the camera view throughout the animation, which means you need a minimum of two motion path curves.

Camera eye

The camera eye can be considered the camera unit itself, which travels along the motion path to which it is assigned. The motion path determines the position of the camera at any given time in relation to the scene. For example, the design of the motion path lets you move the camera closer to or further away from an object in the scene. To visualize, think of yourself walking along with a camera taking pictures: the route you follow would be the motion path.

Camera view

The camera view can be considered the focus point of the camera - where the camera is looking at any given time. If the camera view is not assigned to a motion path of its own, then the view is always directly in front of the camera. Think of yourself walking through a scene without ever pivoting your head, your view is always directly ahead of your body. By assigning the view to a motion path of its own, you can change the view point of the camera at any time in relation to the camera position.

Camera up vector

The camera up vector can be considered the current angle of the camera at any given time in relation to the camera eye. The camera up vector is the direction from the camera's eye to the camera's up. If the camera's up is not assigned a motion path of its own, the camera remains parallel to the path that the eye has been assigned to at all times. By assigning the camera up to an independent motion path, the camera can be pivoted to any angle up to 360 degrees. This can be likened to a camera on a tripod except that the tripod could pivot a full 360 degrees.

How to Use

1

In the Tool Palette, select Anim > Autofly, or click its icon. (If you want to specify options such as start and end frames, select Autofly -.)

The following prompt is displayed:

Select the motion path for the camera EYE to follow

Objects do not have to be active when this function is invoked.

2

Click on the curve you want to assign as the motion path for the camera eye. The curve will change color to indicate that it is now a motion path.

Once the camera eye motion path has been selected, the system prompts:

Select the motion path for the VIEW, or select the GO icon

3

To use a second curve for the camera view, click on the curve that you want to assign as the motion path of the camera view.

If you click the Go icon instead, the system uses a camera view motion path that is straight ahead along the motion path chosen for the camera eye.

4

Once you select the camera view motion path and clicked the Go icon, the system prompts:

Select the motion path for the UP, or select the GO icon

To use a third curve for the camera up, click directly on the curve you want to assign as the camera up path.

If you click the Go icon instead, the system generates the camera up motion path. The camera is oriented in the up direction, and banks around curves according to the current Maximum Bank degree values set in the Autofly Options box.

5

When you are finished selecting curves, a new perspective window is created and its camera is animated along the curves.

6

To halt the animation playback, press the Esc key.

Examples

In the following diagram, only one motion path is used. The camera view is always directly in front of the camera eye as the camera travels along the motion path. The camera view loses sight of the objects as it weaves between them.

In the next diagram, a second curve has been assigned as the motion path for the camera view. In this case, regardless of the camera position on the eye motion path, the camera's view is always directed to the cones as it weaves between them.

Autofly Options

To view or change Autofly options, select Autofly -, or double-click the icon to display the Autofly Options box.

Auto Bank In/Out

Indicates whether the camera tilts into the curve, or away from the center of the curvature, while traveling along the motion path. The Auto Bank option has no effect if the Maximum Bank value is set to 0 degrees.

Maximum Bank Degrees

Indicates the maximum number of degrees the camera banks at the maximum curvature of the eye motion path.

Start Frame/End Frame/By Frames

Indicate the numbers of the first and last frames of the animation, and the frame increment respectively.

Create SDL File

If toggled ON (indicated by a check mark), the system creates an SDL file to record the animation for rendering. In this case, you are prompted to supply an SDL file name in which to store the animation.