Camera (jReality API)

java.lang.Object
- de.jreality.scene.SceneGraphNode
- - de.jreality.scene.Camera

```
public class Camera
extends SceneGraphNode
```
The camera represents essentially a projection from three dimensions into two, that is a specification of a viewing frustrum. The camera coordinate system is assumed to point down the positive z-axis. (Note: specific backends may flip the orientation of the z-axis. This issue is handled separately from the camera description here).
All instance of Camera require specifying the near and far clipping planes.
The camera can be either perspective or orthographic. If it is perspective, then its viewing frustum can be specified by giving the field of view setFieldOfView(double). This implies that the camera is on-axis, that is, the viewing frustum is centered on the z-axis.
There is also support for off-axis cameras (setOnAxis(boolean)). Use the setViewPort(Rectangle2D) method to specify the desired viewport, which is assumed to lie in the z=1 plane. In this case the field of view is ignored.
The camera also supports stereo viewing @link #setStereo(boolean). For most desktop environments the only other required parameters are:
- eye separation (setEyeSeparation(double)), a horizontal displacement in camera coordinates, and
- focus setFocus(double), the z-depth where the two images are identical.
For CAVE-like environments where the eyes are not always oriented horizontally, there is an additional parameter: an orientation matrix (setOrientationMatrix(double[])), a 4x4 transformation matrix which defines the rotation that has to be applied to the x-axis to get the line in camera coordinates on which the eyes lie. (This matrix should fix (0,0,0,1)!).
Default eye positions are (-eyeSeparation/2,0,0) and (eyeSeparation, 0,0) in the camera coordinate system. Use CameraUtility#getNDCToCamera(Camera, double, int) to generate the appropriate projection matrices.
Instances of CameraListener can register with the camera to be notified when the camera changes.
Due to refactoring, the camera no longer has enough state to provide the perspective viewing transformation from/to camera to/from Normalized Device Coordinates (NDC). It basically lacks the aspect ratio of the output device. This allows to use the same camera for different viewers with i. e. different window sizes. See CameraUtility for methods which provide this functionality.
Author:

Charles Gunn

See Also:

CameraUtility

Constructor Summary

Constructors
Constructor and Description

Camera()

Camera(String name)

Constructors
Constructor and Description
`Camera()`
`Camera(String name)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`accept(SceneGraphVisitor v)` The accept method for a SceneGraphVisitor.
`void`	`addCameraListener(CameraListener listener)`
`double`	`getEyeSeparation()`
`double`	`getFar()`
`double`	`getFieldOfView()`
`double`	`getFocalLength()` Values useful in Renderman backend.
`double`	`getFocus()`
`double`	`getFStop()` Values useful in Renderman backend.
`double`	`getNear()`
`double[]`	`getOrientationMatrix()` The orientation matrix describes the transformation in camera coordinate system which describes the orientation of the head; the "standard" position is that the eyes are on the x-axis, up is the y-axis, and z is the direction of projection The orientation matrix is used for cameras such as those in the PORTAL.
`Rectangle2D`	`getViewPort()`
`boolean`	`isLeftEye()`
`boolean`	`isOnAxis()`
`boolean`	`isPerspective()`
`boolean`	`isRightEye()`
`boolean`	`isStereo()`
`void`	`removeCameraListener(CameraListener listener)`
`void`	`setEyeSeparation(double eyeSeparation)`
`void`	`setFar(double d)`
`void`	`setFieldOfView(double d)`
`void`	`setFocalLength(double focalLength)`
`void`	`setFocus(double d)`
`void`	`setFStop(double fstop)`
`void`	`setLeftEye(boolean isLeftEye)`
`void`	`setNear(double d)`
`void`	`setOnAxis(boolean b)`
`void`	`setOrientationMatrix(double[] orientationMatrix)`
`void`	`setPerspective(boolean b)`
`void`	`setRightEye(boolean isRightEye)`
`void`	`setStereo(boolean isStereo)`
`void`	`setViewPort(Rectangle2D rectangle2D)`

Methods inherited from class de.jreality.scene.SceneGraphNode
getName, getOwner, getThreadSafe, isReadOnly, setName, setOwner, setReadOnly, setThreadSafe, toString

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Camera
```
public Camera(String name)
```

Camera
```
public Camera()
```

Method Detail

getNear
```
public double getNear()
```

setNear
```
public void setNear(double d)
```

getFar
```
public double getFar()
```

setFar
```
public void setFar(double d)
```

getFieldOfView
```
public double getFieldOfView()
```

setFieldOfView
```
public void setFieldOfView(double d)
```

getFocus
```
public double getFocus()
```

setFocus
```
public void setFocus(double d)
```

getViewPort
```
public Rectangle2D getViewPort()
```

setViewPort

public void setViewPort(Rectangle2D rectangle2D)

isOnAxis
```
public boolean isOnAxis()
```

setOnAxis
```
public void setOnAxis(boolean b)
```

isPerspective
```
public boolean isPerspective()
```

setPerspective

public void setPerspective(boolean b)

getEyeSeparation
```
public double getEyeSeparation()
```

setEyeSeparation
```
public void setEyeSeparation(double eyeSeparation)
```
Parameters:

eyeSeparation - The eyeSeparation to set.

getOrientationMatrix
```
public double[] getOrientationMatrix()
```
The orientation matrix describes the transformation in camera coordinate system which describes the orientation of the head; the "standard" position is that the eyes are on the x-axis, up is the y-axis, and z is the direction of projection The orientation matrix is used for cameras such as those in the PORTAL.

Returns:

Returns the orientationMatrix.

setOrientationMatrix

public void setOrientationMatrix(double[] orientationMatrix)

isStereo
```
public boolean isStereo()
```

isLeftEye
```
public boolean isLeftEye()
```

isRightEye
```
public boolean isRightEye()
```

setStereo

public void setStereo(boolean isStereo)

setLeftEye

public void setLeftEye(boolean isLeftEye)

setRightEye

public void setRightEye(boolean isRightEye)

addCameraListener

public void addCameraListener(CameraListener listener)

removeCameraListener

public void removeCameraListener(CameraListener listener)

accept
```
public void accept(SceneGraphVisitor v)
```
Description copied from class: SceneGraphNode

The accept method for a SceneGraphVisitor.

Overrides:

accept in class SceneGraphNode

getFocalLength
```
public double getFocalLength()
```
Values useful in Renderman backend.

Returns:

getFStop
```
public double getFStop()
```
Values useful in Renderman backend.

Returns:

setFStop
```
public void setFStop(double fstop)
```

setFocalLength

public void setFocalLength(double focalLength)

Class Camera

Constructor Summary

Method Summary

Methods inherited from class de.jreality.scene.SceneGraphNode

Methods inherited from class java.lang.Object

Constructor Detail

Camera

Camera

Method Detail

getNear

setNear

getFar

setFar

getFieldOfView

setFieldOfView

getFocus

setFocus

getViewPort

setViewPort

isOnAxis

setOnAxis

isPerspective

setPerspective

getEyeSeparation

setEyeSeparation

getOrientationMatrix

setOrientationMatrix

isStereo

isLeftEye

isRightEye

setStereo

setLeftEye

setRightEye

addCameraListener

removeCameraListener

accept

getFocalLength

getFStop

setFStop

setFocalLength