6.4  Camera

The camera definition describes the position, projection type and properties of the camera viewing the scene. Its syntax is:

CAMERA:
    camera{ [CAMERA_ITEMS...] }
CAMERA_ITEM:
    CAMERA_TYPE | CAMERA_VECTOR | CAMERA_MODIFIER |
    CAMERA_IDENTIFIER
CAMERA_TYPE:
    perspective | orthographic | fisheye | ultra_wide_angle |
    omnimax | panoramic | cylinder CylinderType | spherical
CAMERA_VECTOR:
    location <Location> | right <Right> | up <Up> | 
    direction <Direction> | sky <Sky>
CAMERA_MODIFIER:
    angle HORIZONTAL [VERTICAL] | look_at <Look_At> |
    blur_samples Num_of_Samples | aperture Size |
    focal_point <Point> | confidence Blur_Confidence |
    variance Blur_Variance | NORMAL | TRANSFORMATION

Camera default values:

DEFAULT CAMERA:
  camera {
    perspective
    location <0,0,0>
    direction <0,0,1>
    right 1.33*x
    up y
    sky <0,1,0>
  }

CAMERA TYPE: perspective
angle      : ~67.380 ( direction_length=0.5*
                       right_length/tan(angle/2) )
confidence : 0.9 (90%)
direction  : <0,0,1>
focal_point: <0,0,0>
location   : <0,0,0>
look_at    : z
right      : 1.33*x
sky        : <0,1,0>
up         : y
variance   : 1/128

Depending on the projection type zero or more of the parameters are required:

• If no camera is specified the default camera is used.
• If no projection type is given the perspective camera will be used (pinhole camera).
• The CAMERA_TYPE has to be the first item in the camera statement.
• Other CAMERA_ITEMs may legally appear in any order.
• For other than the perspective camera, the minimum that has to be specified is the CAMERA_TYPE, the cylindrical camera also requires the CAMERA_TYPE to be followed by a float.
• The Orthographic camera has two 'modes'. For the pure orthographic projection up or right have to be specified. For an orthographic camera, with the same area of view as a perspective camera at the plane which goes through the look_at point, the angle keyword has to be use. A value for the angle is optional.
• All other CAMERA_ITEMs are taken from the default camera, unless they are specified differently.