org.opensourcephysics.display3d.core
Interface Camera

All Known Implementing Classes:

Camera

public interface Camera

Title: Camera

Description: This class provides access to the position of the camera, its focus point and its distance to the projection screen that are used to view the 3D scenes. The camera can also be rotated around the line of sight (i.e. the line which conects the camera with the focus point).

The camera position can be set using either the desired X,Y,Z coordinates or spherical coordinates around the focus point. This makes it easy to rotate the scene both horizontally and vertically (around the focus).

Panning can be achieved by moving the focus point to one side.

Zooming is done increasing (positive zoom) or decreasing the distance between the camera and the projection screen.

The projection screen is always normal to the line of sight and has its origin at the intersection of this line with the screen itself.

The camera provides fives different modes of projecting points in space to the screen. Two modes are truly three-dimensional. The other three are planar modes.

See Also:

setProjectionMode(int)

Nested Class Summary

static class

Camera.Loader

Field Summary

static int	MODE_NO_PERSPECTIVE
static int	MODE_PERSPECTIVE
static int	MODE_PLANAR_XY
static int	MODE_PLANAR_XZ
static int	MODE_PLANAR_YZ

Method Summary

double	getAltitude() Get the elevation (vertical) angle of the camera position in spherical coordinates with respect to the focus point.
double	getAzimuth() Get the horizontal angle of the camera position in spherical coordinates with respect to the focus point.
double	getDistanceToScreen() Returns the distance from the camera to the projecting screen.
double	getFocusX() Returns the focus X coordinate
double	getFocusY() Returns the focus Y coordinate
double	getFocusZ() Returns the focus Z coordinate
int	getProjectionMode() Gets the projecting mode of the camera.
double	getRotation() Returns the angle that the camera is rotated along the line of sight.
Transformation	getTransformation() Returns the transfomation used to project (x,y,z) points in space to points of the form (a,b,distance).
double	getX() Returns the camera X coordinate
double	getY() Returns the camera Y coordinate
double	getZ() Returns the camera Z coordinate
void	reset() Resets the camera to the default.
void	setAltitude(double angle) Set the elevation (vertical) angle of the camera position in spherical coordinates with respect to the focus point.
void	setAzimuth(double angle) Set the azimuthal (horizontal) angle of the camera position in spherical coordinates with respect to the focus point.
void	setAzimuthAndAltitude(double azimuth, double altitude) Set the angles of the camera position in spherical coordinates with respect to the focus point.
void	setDistanceToScreen(double distance) Sets the distance from the camera to the projecting screen.
void	setFocusXYZ(double[] point) Sets the focus of the camera.
void	setFocusXYZ(double x, double y, double z) Sets the focus point of the camera.
void	setProjectionMode(int mode) Sets one of the projecting modes.
void	setRotation(double angle) Sets the angle that the camera is rotated along the line of sight.
void	setXYZ(double[] point) Sets the position of the camera.
void	setXYZ(double x, double y, double z) Sets the position of the camera.

Field Detail

MODE_PLANAR_XY

public static final int MODE_PLANAR_XY

See Also:

Constant Field Values

MODE_PLANAR_XZ

public static final int MODE_PLANAR_XZ

See Also:

Constant Field Values

MODE_PLANAR_YZ

public static final int MODE_PLANAR_YZ

See Also:

Constant Field Values

MODE_NO_PERSPECTIVE

public static final int MODE_NO_PERSPECTIVE

See Also:

Constant Field Values

MODE_PERSPECTIVE

public static final int MODE_PERSPECTIVE

See Also:

Constant Field Values

Method Detail

setProjectionMode

public void setProjectionMode(int mode)

Sets one of the projecting modes. Possible values are:

• MODE_PERSPECTIVE: 3D mode in which objects far away look smaller.
• MODE_NO_PERSPECTIVE: 3D mode in which distance doesn't affect the size of the objects
• MODE_PLANAR_XY: 2D mode in which only the X and Y coordinates are displayed.
• MODE_PLANAR_XZ: 2D mode in which only the X and Z coordinates are displayed.
• MODE_PLANAR_YZ: 2D mode in which only the Y and Z coordinates are displayed.

Changing the mode does not reset the camera.

Parameters:

mode - int

getProjectionMode

public int getProjectionMode()

Gets the projecting mode of the camera.

Returns:

int #see #setProjectionMode(int)

reset

public void reset()

Resets the camera to the default. The camera is placed along the X direction, at a reasonable distance from the center of the panel, which becomes the focus, and is not rotated. The screen is also placed at a reasonable distance so that to view the whole scene.

setXYZ

public void setXYZ(double x,
                   double y,
                   double z)

Sets the position of the camera.

Parameters:

x - double

y - double

z - double

setXYZ

public void setXYZ(double[] point)

Sets the position of the camera.

Parameters:

point - double[]

getX

public double getX()

Returns the camera X coordinate

Returns:

double the X coordinate of the camera position

getY

public double getY()

Returns the camera Y coordinate

Returns:

double the Y coordinate of the camera position

getZ

public double getZ()

Returns the camera Z coordinate

Returns:

double the Z coordinate of the camera position

setFocusXYZ

public void setFocusXYZ(double x,
                        double y,
                        double z)

Sets the focus point of the camera. That it, the point in space at which the camera is pointing.

Parameters:

x - double

y - double

z - double

setFocusXYZ

public void setFocusXYZ(double[] point)

Sets the focus of the camera.

Parameters:

point - double[]

getFocusX

public double getFocusX()

Returns the focus X coordinate

Returns:

double the X coordinate of the focus position

getFocusY

public double getFocusY()

Returns the focus Y coordinate

Returns:

double the Y coordinate of the focus position

getFocusZ

public double getFocusZ()

Returns the focus Z coordinate

Returns:

double the Z coordinate of the focus position

setRotation

public void setRotation(double angle)

Sets the angle that the camera is rotated along the line of sight. Default is 0.

Parameters:

angle - double The angle in radians

getRotation

public double getRotation()

Returns the angle that the camera is rotated along the line of sight.

Returns:

double

setDistanceToScreen

public void setDistanceToScreen(double distance)

Sets the distance from the camera to the projecting screen.

Parameters:

distance - double

getDistanceToScreen

public double getDistanceToScreen()

Returns the distance from the camera to the projecting screen.

Returns:

double

setAzimuth

public void setAzimuth(double angle)

Set the azimuthal (horizontal) angle of the camera position in spherical coordinates with respect to the focus point. A value of 0 places the camera in the XZ plane.

Parameters:

angle - the desired angle in radians

getAzimuth

public double getAzimuth()

Get the horizontal angle of the camera position in spherical coordinates with respect to the focus point. A value of 0 means the camera is in the XZ plane.

Returns:

double

setAltitude

public void setAltitude(double angle)

Set the elevation (vertical) angle of the camera position in spherical coordinates with respect to the focus point. A value of 0 places the camera is in the XY plane.

Parameters:

angle - the desired angle in radians in the range [-Math.PI/2,Math.PI/2]

getAltitude

public double getAltitude()

Get the elevation (vertical) angle of the camera position in spherical coordinates with respect to the focus point. A value of 0 means the camera is in the XY plane.

Returns:

double

setAzimuthAndAltitude

public void setAzimuthAndAltitude(double azimuth,
                                  double altitude)

Set the angles of the camera position in spherical coordinates with respect to the focus point.

Parameters:

azimuth - the desired azimuthal angle in radians

altitude - the desired altitude angle in radians in the range [-Math.PI/2,Math.PI/2]

getTransformation

public Transformation getTransformation()

Returns the transfomation used to project (x,y,z) points in space to points of the form (a,b,distance). (a,b) are the coordinates of the projected point in the screen coordinate system. distance is a measure of how far the point is from the camera. Typically, points in the plane parallel to the screen at the focus point are at distance=1.

Returns:

double