JavaFX 3D - JavaFX 8: A Definitive Guide to Building Desktop, Mobile, and Embedded Java Clients - page 445

same size regardless of distance to the camera. This is called orthographic projection, and although much easier
to calculate, it does not look realistic. The PerspectiveCamera is more interesting for 3D modeling. When using a
PerspectiveCamera , objects in the distance are smaller than objects in the foreground.

Understanding the PerspectiveCamera
The PerspectiveCamera class has the following public constructors:
•

PerspectiveCamera()

PerspectiveCamera(boolean fixedEyeAtCameraZero)
The default constructor creates a PerspectiveCamera with the fixedEyeAtCameraZero set to false. The
one-parameter constructor creates a PerspectiveCamera with the specified fixedEyeAtCameraZero. Cameras are
Node s, and can be placed in a JavaFX scene. A newly created PerspectiveCamera , like a newly created Sphere or
Cylinder or Box , has its center or eye located in the origin (0, 0, 0) of the three-dimensional space. The eye looks into
the positive z direction. As a Node , the PerspectiveCamera itself can be transformed by 3D transformations such as
Rotate , Translate , Scale , or even the generic Affine . A fixedEyeAtCameraZero setting of true guarantees that after
such transforms, the eye of the PerspectiveCamera moves along with it, and remains at the camera's zero position. A
fixedEyeAtCameraZero setting of false allows the eye to drift away from the camera's zero position to accommodate
what is in the scene. This is useful for rendering 2D scenes and only makes sense when the camera itself is not
transformed in any way. Therefore for use with a 3D model, you should always use the one-parameter constructor,
passing in a fixedEyeAtCameraZero of true .
The PerspectiveCamera class has the following public methods:
•

•

void setFieldOfView(double)

•

double getFieldOfView()

•

DoubleProperty fieldOfViewProperty()

•

void setVerticalFieldOfView(boolean)

•

boolean isVerticalFieldOfView()

•

BooleanProperty verticalFieldOfViewProperty()

boolean isFixedEyeAtCameraZero()
These methods define two properties, fieldOfView and verticalFieldOfView , for the PerspectiveCamera
class. The fieldOfView is a double property and represents the field of view of the perspective camera in degrees.
The default value is 30 degrees. The verticalFieldOfView is a boolean property that determines if the field of view
property applies to the vertical dimension of the projection plane. The isFixedEyeAtCameraZero() method returns
the fixedEyeAtCameraZero flag the PerspectiveCamera is constructed with.
The PerspectiveCamera also inherits two double properties from the Camera abstract class: nearClip and
farClip . Objects closer to the eye than nearClip and objects farther from the eye than farClip are not rendered in
the scene.
In the program in Listing 10-5, we create a Box and a PerspectiveCamera . Unlike in previous examples where
we transform the 3D objects themselves like the Box , in this program we keep the Box fixed and transform the
PerspectiveCamera with a combination of rotating around the x axis, rotating around the y axis, and a translation
along the z axis. We animate the rotation degrees from 90 to -90 and the z translation from -20 to -80 in a five-second
Timeline .

•