Lens and FOV
Lens field sets the camera’s focal length in millimeters. Use the lens spinner to give the focal length a value other than the preset “stock” values on the buttons in the stock lenses group box.
FOV (which stands for field of view), sets the width of the area that the camera displays. The value is specified in degrees and can be set to represent a Horizontal, Vertical, or Diagonal distance using the flyout button to its left.
When on, the camera view looks just like a User view. When off, the camera view is the standard perspective-like view. While Orthographic Projection is in effect, the view port navigation buttons behave as they ordinarily do, except for Perspective. Perspective function still moves the camera and changes the FOV, but the Orthographic Projection cancels the two out, so you don’t see any change until you turn off Orthographic Projection.
Standard stock lenses can be simulated in Max by clicking one of the Stock Lens buttons. Preset stock lenses include 15, 20, 24, 28, 35, 50, 85, 135, and 200mm lengths. The Lens and FOV fields are automatically updated on stock lens selection.
Camera Type and Display Options
Camera type changes the camera’s type from a Target Camera to a Free Camera, and vice versa.
The Show Cone option enables you to display the camera’s cone, showing the boundaries of the camera view when the camera isn’t selected. The Show Horizon option displays the horizon line. A dark gray line appears at the level of the horizon in the camera’s viewport.
Enviroment Ranges and Clipping
Environment ranges determine the near and far range limits for atmospheric effects you set in the Environment dialog.
Clipping planes let you exclude some of the scene´s geometry to view or render only certain portions of the scene. Objects closer than the near clipping plane or farther than the far clipping plane are invisible to the camera. The location of each clipping plane is measured along the camera's line of sight (its local Z axis) in the current units for the scene. In viewports, clipping planes are displayed as red rectangles (with diagonals) within the camera’s cone.
Multi-Pass Camera Effects
All cameras have the option to enable them to become multi-pass cameras. You can find these settings in the Parameters rollout when a camera object is selected. Checking the Enable button and selecting the effect from the drop-down list creates multi-pass cameras.
The available effects include Depth of Field (mental ray), Depth of Field, and Motion Blur. For each, an associated rollout of parameters opens.
The Multi-Pass Effect section of the Parameters rollout also includes a Preview button. This button makes the effect visible in the viewports. This feature can save you a significant amount of time that normally would be spent test-rendering the scene. The Preview button is worth its weight in render speed. Using this button, you can preview the effect without having to render the entire sequence.
The Render Effect Per Pass option causes any applied Render Effect to be applied at each pass. If disabled, then any of the applied Render Effect is applied after the passes are completed.
The Camera Match tool is used to align a camera’s position to the background image. After you align the camera to the position that was used to take the image, you can place 3D objects within your scene and be assured that they will line up correctly with the objects within the image. For example, if you take a picture of a street scene and align the camera with the background image, then any cars or buildings that you digitally add to the scene are correctly aligned.
Figure 8-5: Camera Match utility
You can find the Camera Match tool in the Utilities panel. Before you can use this tool, you need to load a bitmap image as a background.
The Camera Tracker utility recreates the movements of a camera that was used to create an animated background. As with the Camera Match utility, you access the Camera Tracker utility from the Utilities panel. Click on the More button to open the Utilities dialog box, and select the Camera Tracker from the list of additional utilities.