Panda3D
Public Types | Public Member Functions | Static Public Member Functions | Public Attributes | List of all members
Lens Class Reference

A base class for any number of different kinds of lenses, linear and otherwise. More...

Inheritance diagram for Lens:
TypedWritableReferenceCount TypedWritable ReferenceCount TypedObject MatrixLens OrthographicLens PerspectiveLens CylindricalLens FisheyeLens OSphereLens PSphereLens

Public Types

enum  FromCorners {
  FC_roll = 1, FC_camera_plane = 2, FC_off_axis = 4, FC_aspect_ratio = 8,
  FC_shear = 16, FC_keystone = 32
}
 
enum  StereoChannel { SC_mono = 0, SC_left = 1, SC_right = 2, SC_stereo = 3 }
 

Public Member Functions

 clear ()
 Resets all lens parameters to their initial default settings. More...
 
 clearCustomFilmMat ()
 Disables the lens custom_film_mat correction. More...
 
 clearKeystone ()
 Disables the lens keystone correction. More...
 
 clearViewMat ()
 Resets the lens transform to identity. More...
 
bool extrude (const LPoint2 point2d, LPoint3 near_point, LPoint3 far_point)
 Given a 2-d point in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner, compute the corresponding vector in space that maps to this point, if such a vector can be determined. More...
 
bool extrude (const LPoint3 point2d, LPoint3 near_point, LPoint3 far_point)
 Given a 2-d point in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner, compute the corresponding vector in space that maps to this point, if such a vector can be determined. More...
 
bool extrudeDepth (const LPoint3 point2d, LPoint3 point3d)
 Uses the depth component of the 3-d result from project() to compute the original point in 3-d space corresponding to a particular point on the lens. More...
 
bool extrudeVec (const LPoint2 point2d, LVector3 vec3d)
 Given a 2-d point in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner, compute the vector that corresponds to the view direction. More...
 
bool extrudeVec (const LPoint3 point2d, LVector3 vec3d)
 Given a 2-d point in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner, compute the vector that corresponds to the view direction. More...
 
float getAspectRatio ()
 Returns the aspect ratio of the Lens. More...
 
str getChangeEvent ()
 Returns the name of the event that will be generated whenever any properties of this particular Lens have changed. More...
 
float getConvergenceDistance ()
 See set_convergence_distance(). More...
 
CoordinateSystem getCoordinateSystem ()
 Returns the coordinate system that all 3-d computations are performed within for this Lens. More...
 
const LMatrix4 getCustomFilmMat ()
 Returns the custom_film_mat specified for the lens. More...
 
float getFar ()
 Returns the position of the far plane (or cylinder, sphere, whatever). More...
 
const LMatrix4 getFilmMat ()
 Returns the matrix that transforms from a point behind the lens to a point on the film. More...
 
const LMatrix4 getFilmMatInv ()
 Returns the matrix that transforms from a point on the film to a point behind the lens. More...
 
const LVector2 getFilmOffset ()
 Returns the horizontal and vertical offset amounts of this Lens. More...
 
const LVecBase2 getFilmSize ()
 Returns the horizontal and vertical film size of the virtual film. More...
 
float getFocalLength ()
 Returns the focal length of the lens. More...
 
const LVecBase2 getFov ()
 Returns the horizontal and vertical film size of the virtual film. More...
 
float getHfov ()
 Returns the horizontal component of fov only. More...
 
float getInterocularDistance ()
 See set_interocular_distance(). More...
 
const LVecBase2 getKeystone ()
 Returns the keystone correction specified for the lens. More...
 
UpdateSeq getLastChange ()
 Returns the UpdateSeq that is incremented whenever the lens properties are changed. More...
 
const LMatrix4 getLensMat ()
 Returns the matrix that transforms from a point in front of the lens to a point in space. More...
 
const LMatrix4 getLensMatInv ()
 Returns the matrix that transforms from a point in space to a point in front of the lens. More...
 
float getMinFov ()
 Returns the field of view of the narrowest dimension of the window. More...
 
float getNear ()
 Returns the position of the near plane (or cylinder, sphere, whatever). More...
 
LPoint3 getNodalPoint ()
 Returns the center point of the lens: the point from which the lens is viewing. More...
 
const LMatrix4 getProjectionMat (Lens::StereoChannel channel)
 Returns the complete transformation matrix from a 3-d point in space to a point on the film, if such a matrix exists, or the identity matrix if the lens is nonlinear. More...
 
const LMatrix4 getProjectionMatInv (Lens::StereoChannel channel)
 Returns the matrix that transforms from a 2-d point on the film to a 3-d vector in space, if such a matrix exists. More...
 
const LVector3 getUpVector ()
 Returns the axis perpendicular to the camera's view vector that indicates the "up" direction. More...
 
float getVfov ()
 Returns the vertical component of fov only. More...
 
const LVecBase3 getViewHpr ()
 Returns the direction in which the lens is facing. More...
 
const LMatrix4 getViewMat ()
 Returns the direction in which the lens is facing. More...
 
const LVector3 getViewVector ()
 Returns the axis along which the lens is facing. More...
 
bool isLinear ()
 Returns true if the lens represents a linear projection (e.g. More...
 
bool isOrthographic ()
 Returns true if the lens represents a orthographic projection (i.e. More...
 
bool isPerspective ()
 Returns true if the lens represents a perspective projection (i.e. More...
 
BoundingVolume makeBounds ()
 Allocates and returns a new BoundingVolume that encloses the frustum used for this kind of lens, if possible. More...
 
Lens makeCopy ()
 
Geom makeGeometry ()
 Allocates and returns a new Geom that can be rendered to show a visible representation of the frustum used for this kind of lens, if it makes sense to do so. More...
 
 output (Ostream out)
 
bool project (const LPoint3 point3d, LPoint2 point2d)
 Given a 3-d point in space, determine the 2-d point this maps to, in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner. More...
 
bool project (const LPoint3 point3d, LPoint3 point2d)
 Given a 3-d point in space, determine the 2-d point this maps to, in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner. More...
 
 recomputeAll ()
 Forces all internal parameters of the Lens to be recomputed. More...
 
 setAspectRatio (float aspect_ratio)
 Sets the aspect ratio of the lens. More...
 
 setChangeEvent (str event)
 Sets the name of the event that will be generated whenever any properties of the Lens have changed. More...
 
 setConvergenceDistance (float convergence_distance)
 Sets the distance between between the camera plane and the point in the distance that the left and right eyes are both looking at. More...
 
 setCoordinateSystem (CoordinateSystem cs)
 Specifies the coordinate system that all 3-d computations are performed within for this Lens. More...
 
 setCustomFilmMat (const LMatrix4 custom_film_mat)
 Specifies a custom matrix to transform the points on the film after they have been converted into nominal film space (-1 . More...
 
 setFar (float far_distance)
 Defines the position of the far plane (or cylinder, sphere, whatever). More...
 
 setFilmOffset (const LVecBase2 film_offset)
 Sets the horizontal and vertical offset amounts of this Lens. More...
 
 setFilmOffset (float x, float y)
 Sets the horizontal and vertical offset amounts of this Lens. More...
 
 setFilmSize (const LVecBase2 film_size)
 Sets the size and shape of the "film" within the lens. More...
 
 setFilmSize (float width)
 Sets the horizontal size of the film without changing its shape. More...
 
 setFilmSize (float width, float height)
 Sets the size and shape of the "film" within the lens. More...
 
 setFocalLength (float focal_length)
 Sets the focal length of the lens. More...
 
 setFov (const LVecBase2 fov)
 Sets the field of view of the lens in both dimensions. More...
 
 setFov (float fov)
 Sets the horizontal field of view of the lens without changing the aspect ratio. More...
 
 setFov (float hfov, float vfov)
 Sets the field of view of the lens in both dimensions. More...
 
 setFrustumFromCorners (const LVecBase3 ul, const LVecBase3 ur, const LVecBase3 ll, const LVecBase3 lr, int flags)
 Sets up the lens to use the frustum defined by the four indicated points. More...
 
 setInterocularDistance (float interocular_distance)
 Sets the distance between the left and right eyes of a stereo camera. More...
 
 setKeystone (const LVecBase2 keystone)
 Indicates the ratio of keystone correction to perform on the lens, in each of three axes. More...
 
 setMinFov (float min_fov)
 Sets the field of view of the smallest dimension of the window. More...
 
 setNear (float near_distance)
 Defines the position of the near plane (or cylinder, sphere, whatever). More...
 
 setNearFar (float near_distance, float far_distance)
 Simultaneously changes the near and far planes. More...
 
 setViewHpr (const LVecBase3 view_hpr)
 Sets the direction in which the lens is facing. More...
 
 setViewHpr (float h, float p, float r)
 Sets the direction in which the lens is facing. More...
 
 setViewMat (const LMatrix4 view_mat)
 Sets an arbitrary transformation on the lens. More...
 
 setViewVector (const LVector3 view_vector, const LVector3 up_vector)
 Specifies the direction in which the lens is facing by giving an axis to look along, and a perpendicular (or at least non-parallel) up axis. More...
 
 setViewVector (float x, float y, float z, float i, float j, float k)
 Specifies the direction in which the lens is facing by giving an axis to look along, and a perpendicular (or at least non-parallel) up axis. More...
 
 write (Ostream out, int indent_level)
 
- Public Member Functions inherited from TypedWritable
object __reduce__ ()
 
object __reduce_persist__ (object pickler)
 
VectorUchar encodeToBamStream ()
 Converts the TypedWritable object into a single stream of data using a BamWriter, and returns that data as a bytes object. More...
 
bool encodeToBamStream (VectorUchar data, BamWriter writer)
 Converts the TypedWritable object into a single stream of data using a BamWriter, and stores that data in the indicated string. More...
 
 fillin (DatagramIterator scan, BamReader manager)
 This internal function is intended to be called by each class's make_from_bam() method to read in all of the relevant data from the BamFile for the new object. More...
 
UpdateSeq getBamModified ()
 Returns the current bam_modified counter. More...
 
 markBamModified ()
 Increments the bam_modified counter, so that this object will be invalidated and retransmitted on any open bam streams. More...
 
- Public Member Functions inherited from TypedObject
TypeHandle getType ()
 
int getTypeIndex ()
 Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. More...
 
bool isExactType (TypeHandle handle)
 Returns true if the current object is the indicated type exactly. More...
 
bool isOfType (TypeHandle handle)
 Returns true if the current object is or derives from the indicated type. More...
 
- Public Member Functions inherited from ReferenceCount
int getRefCount ()
 Returns the current reference count. More...
 
 ref ()
 Explicitly increments the reference count. More...
 
bool testRefCountIntegrity ()
 Does some easy checks to make sure that the reference count isn't completely bogus. More...
 
bool testRefCountNonzero ()
 Does some easy checks to make sure that the reference count isn't zero, or completely bogus. More...
 
bool unref ()
 Explicitly decrements the reference count. More...
 

Static Public Member Functions

static TypeHandle getClassType ()
 
static float getDefaultFar ()
 Returns the default far plane distance that will be assigned to each newly- created lens. More...
 
static float getDefaultNear ()
 Returns the default near plane distance that will be assigned to each newly-created lens. More...
 
- Static Public Member Functions inherited from TypedWritableReferenceCount
static TypedWritableReferenceCount decodeFromBamStream (VectorUchar data, BamReader reader)
 Reads the bytes created by a previous call to encode_to_bam_stream(), and extracts and returns the single object on those bytes. More...
 
static TypeHandle getClassType ()
 
- Static Public Member Functions inherited from TypedWritable
static TypeHandle getClassType ()
 
- Static Public Member Functions inherited from TypedObject
static TypeHandle getClassType ()
 
- Static Public Member Functions inherited from ReferenceCount
static TypeHandle getClassType ()
 

Public Attributes

float aspect_ratio
 Returns the aspect ratio of the Lens. More...
 
const String change_event
 Returns the name of the event that will be generated whenever any properties of this particular Lens have changed. More...
 
float convergence_distance
 See set_convergence_distance(). More...
 
CoordinateSystem coordinate_system
 Returns the coordinate system that all 3-d computations are performed within for this Lens. More...
 
float far
 Returns the position of the far plane (or cylinder, sphere, whatever). More...
 
const LVector2 film_offset
 Returns the horizontal and vertical offset amounts of this Lens. More...
 
const LVecBase2 film_size
 Returns the horizontal and vertical film size of the virtual film. More...
 
float focal_length
 Returns the focal length of the lens. More...
 
const LVecBase2 fov
 Returns the horizontal and vertical film size of the virtual film. More...
 
float interocular_distance
 See set_interocular_distance(). More...
 
const LVecBase2 keystone
 Returns the keystone correction specified for the lens. More...
 
float min_fov
 Returns the field of view of the narrowest dimension of the window. More...
 
float near
 Returns the position of the near plane (or cylinder, sphere, whatever). More...
 
LPoint3 nodal_point
 Returns the center point of the lens: the point from which the lens is viewing. More...
 
const LVecBase3 view_hpr
 Returns the direction in which the lens is facing. More...
 
const LMatrix4 view_mat
 Returns the direction in which the lens is facing. More...
 
- Public Attributes inherited from TypedObject
TypeHandle type
 Returns the TypeHandle representing this object's type. More...
 
- Public Attributes inherited from ReferenceCount
int ref_count
 The current reference count. More...
 

Detailed Description

A base class for any number of different kinds of lenses, linear and otherwise.

Presently, this includes perspective and orthographic lenses.

A Lens object is the main part of a Camera node, which defines the fundamental interface to point-of-view for rendering. Lenses are also used in other contexts, however; for instance, a Spotlight is also defined using a lens.

Member Enumeration Documentation

◆ FromCorners

Enumerator
FC_roll 
FC_camera_plane 
FC_off_axis 
FC_aspect_ratio 
FC_shear 
FC_keystone 

◆ StereoChannel

Enumerator
SC_mono 
SC_left 
SC_right 
SC_stereo 

== SC_left | SC_right

Member Function Documentation

◆ clear()

clear ( )

Resets all lens parameters to their initial default settings.

◆ clearCustomFilmMat()

clearCustomFilmMat ( )

Disables the lens custom_film_mat correction.

◆ clearKeystone()

clearKeystone ( )

Disables the lens keystone correction.

◆ clearViewMat()

clearViewMat ( )

Resets the lens transform to identity.

◆ extrude() [1/2]

bool extrude ( const LPoint2  point2d,
LPoint3  near_point,
LPoint3  far_point 
)

Given a 2-d point in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner, compute the corresponding vector in space that maps to this point, if such a vector can be determined.

The vector is returned by indicating the points on the near plane and far plane that both map to the indicated 2-d point.

Returns true if the vector is defined, or false otherwise.

◆ extrude() [2/2]

bool extrude ( const LPoint3  point2d,
LPoint3  near_point,
LPoint3  far_point 
)

Given a 2-d point in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner, compute the corresponding vector in space that maps to this point, if such a vector can be determined.

The vector is returned by indicating the points on the near plane and far plane that both map to the indicated 2-d point.

The z coordinate of the 2-d point is ignored.

Returns true if the vector is defined, or false otherwise.

◆ extrudeDepth()

bool extrudeDepth ( const LPoint3  point2d,
LPoint3  point3d 
)

Uses the depth component of the 3-d result from project() to compute the original point in 3-d space corresponding to a particular point on the lens.

This exactly reverses project(), assuming the point does fall legitimately within the lens.

◆ extrudeVec() [1/2]

bool extrudeVec ( const LPoint2  point2d,
LVector3  vec3d 
)

Given a 2-d point in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner, compute the vector that corresponds to the view direction.

This will be parallel to the normal on the surface (the far plane) corresponding to the lens shape at this point.

See the comment block on Lens::extrude_vec_impl() for a more in-depth comment on the meaning of this vector.

Returns true if the vector is defined, or false otherwise.

◆ extrudeVec() [2/2]

bool extrudeVec ( const LPoint3  point2d,
LVector3  vec3d 
)

Given a 2-d point in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner, compute the vector that corresponds to the view direction.

This will be parallel to the normal on the surface (the far plane) corresponding to the lens shape at this point.

See the comment block on Lens::extrude_vec_impl() for a more in-depth comment on the meaning of this vector.

The z coordinate of the 2-d point is ignored.

Returns true if the vector is defined, or false otherwise.

◆ getAspectRatio()

float getAspectRatio ( )

Returns the aspect ratio of the Lens.

This is determined based on the indicated film size; see set_film_size().

◆ getChangeEvent()

str getChangeEvent ( )

Returns the name of the event that will be generated whenever any properties of this particular Lens have changed.

◆ getClassType()

static TypeHandle getClassType ( )
static

◆ getConvergenceDistance()

float getConvergenceDistance ( )

See set_convergence_distance().

◆ getCoordinateSystem()

CoordinateSystem getCoordinateSystem ( )

Returns the coordinate system that all 3-d computations are performed within for this Lens.

Normally, this is CS_default.

◆ getCustomFilmMat()

const LMatrix4 getCustomFilmMat ( )

Returns the custom_film_mat specified for the lens.

◆ getDefaultFar()

static float getDefaultFar ( )
static

Returns the default far plane distance that will be assigned to each newly- created lens.

This is read from the Config.prc file.

◆ getDefaultNear()

static float getDefaultNear ( )
static

Returns the default near plane distance that will be assigned to each newly-created lens.

This is read from the Config.prc file.

◆ getFar()

float getFar ( )

Returns the position of the far plane (or cylinder, sphere, whatever).

◆ getFilmMat()

const LMatrix4 getFilmMat ( )

Returns the matrix that transforms from a point behind the lens to a point on the film.

◆ getFilmMatInv()

const LMatrix4 getFilmMatInv ( )

Returns the matrix that transforms from a point on the film to a point behind the lens.

◆ getFilmOffset()

const LVector2 getFilmOffset ( )

Returns the horizontal and vertical offset amounts of this Lens.

See set_film_offset().

◆ getFilmSize()

const LVecBase2 getFilmSize ( )

Returns the horizontal and vertical film size of the virtual film.

See set_film_size().

◆ getFocalLength()

float getFocalLength ( )

Returns the focal length of the lens.

This may have been set explicitly by a previous call to set_focal_length(), or it may be computed based on the lens' fov and film_size. For certain kinds of lenses, the focal length has no meaning.

◆ getFov()

const LVecBase2 getFov ( )

Returns the horizontal and vertical film size of the virtual film.

See set_fov().

◆ getHfov()

float getHfov ( )

Returns the horizontal component of fov only.

See get_fov().

◆ getInterocularDistance()

float getInterocularDistance ( )

See set_interocular_distance().

◆ getKeystone()

const LVecBase2 getKeystone ( )

Returns the keystone correction specified for the lens.

◆ getLastChange()

UpdateSeq getLastChange ( )

Returns the UpdateSeq that is incremented whenever the lens properties are changed.

As long as this number remains the same, you may assume the lens properties are unchanged.

◆ getLensMat()

const LMatrix4 getLensMat ( )

Returns the matrix that transforms from a point in front of the lens to a point in space.

◆ getLensMatInv()

const LMatrix4 getLensMatInv ( )

Returns the matrix that transforms from a point in space to a point in front of the lens.

◆ getMinFov()

float getMinFov ( )

Returns the field of view of the narrowest dimension of the window.

See set_min_fov().

◆ getNear()

float getNear ( )

Returns the position of the near plane (or cylinder, sphere, whatever).

◆ getNodalPoint()

LPoint3 getNodalPoint ( )

Returns the center point of the lens: the point from which the lens is viewing.

◆ getProjectionMat()

const LMatrix4 getProjectionMat ( Lens::StereoChannel  channel)

Returns the complete transformation matrix from a 3-d point in space to a point on the film, if such a matrix exists, or the identity matrix if the lens is nonlinear.

◆ getProjectionMatInv()

const LMatrix4 getProjectionMatInv ( Lens::StereoChannel  channel)

Returns the matrix that transforms from a 2-d point on the film to a 3-d vector in space, if such a matrix exists.

◆ getUpVector()

const LVector3 getUpVector ( )

Returns the axis perpendicular to the camera's view vector that indicates the "up" direction.

◆ getVfov()

float getVfov ( )

Returns the vertical component of fov only.

See get_fov().

◆ getViewHpr()

const LVecBase3 getViewHpr ( )

Returns the direction in which the lens is facing.

◆ getViewMat()

const LMatrix4 getViewMat ( )

Returns the direction in which the lens is facing.

◆ getViewVector()

const LVector3 getViewVector ( )

Returns the axis along which the lens is facing.

◆ isLinear()

bool isLinear ( )

Returns true if the lens represents a linear projection (e.g.

PerspectiveLens, OrthographicLens), and therefore there is a valid matrix returned by get_projection_mat(), or false otherwise.

◆ isOrthographic()

bool isOrthographic ( )

Returns true if the lens represents a orthographic projection (i.e.

it is a OrthographicLens), false otherwise.

◆ isPerspective()

bool isPerspective ( )

Returns true if the lens represents a perspective projection (i.e.

it is a PerspectiveLens), false otherwise.

◆ makeBounds()

BoundingVolume makeBounds ( )

Allocates and returns a new BoundingVolume that encloses the frustum used for this kind of lens, if possible.

If a suitable bounding volume cannot be created, returns NULL.

◆ makeCopy()

Lens makeCopy ( )

◆ makeGeometry()

Geom makeGeometry ( )

Allocates and returns a new Geom that can be rendered to show a visible representation of the frustum used for this kind of lens, if it makes sense to do so.

If a visible representation cannot be created, returns NULL.

◆ output()

output ( Ostream  out)

◆ project() [1/2]

bool project ( const LPoint3  point3d,
LPoint2  point2d 
)

Given a 3-d point in space, determine the 2-d point this maps to, in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner.

Returns true if the 3-d point is in front of the lens and within the viewing frustum (in which case point2d is filled in), or false otherwise (in which case point2d will be filled in with something, which may or may not be meaningful).

◆ project() [2/2]

bool project ( const LPoint3  point3d,
LPoint3  point2d 
)

Given a 3-d point in space, determine the 2-d point this maps to, in the range (-1,1) in both dimensions, where (0,0) is the center of the lens and (-1,-1) is the lower-left corner.

The z coordinate will also be set to a value in the range (-1, 1), where 1 represents a point on the near plane, and -1 represents a point on the far plane.

Returns true if the 3-d point is in front of the lens and within the viewing frustum (in which case point2d is filled in), or false otherwise (in which case point2d will be filled in with something, which may or may not be meaningful).

◆ recomputeAll()

recomputeAll ( )

Forces all internal parameters of the Lens to be recomputed.

Normally, this should never need to be called; it is provided only to assist in debugging.

◆ setAspectRatio()

setAspectRatio ( float  aspect_ratio)

Sets the aspect ratio of the lens.

This is the ratio of the height to the width of the generated image. Setting this overrides the two-parameter fov or film size setting.

◆ setChangeEvent()

setChangeEvent ( str  event)

Sets the name of the event that will be generated whenever any properties of the Lens have changed.

If this is not set for a particular lens, no event will be generated.

The event is thrown with one parameter, the lens itself. This can be used to automatically track changes to camera fov, etc. in the application.

◆ setConvergenceDistance()

setConvergenceDistance ( float  convergence_distance)

Sets the distance between between the camera plane and the point in the distance that the left and right eyes are both looking at.

This distance is used to apply a stereo effect when the lens is rendered on a stereo display region. It only has an effect on a PerspectiveLens.

This parameter must be greater than 0, but may be as large as you like. It controls the distance at which the two stereo images will appear to converge, which is a normal property of stereo vision. Normally this should be set to the distance from the camera to the area of interest in your scene. Anything beyond this distance will appear to go into the screen, and anything closer will appear to come out of the screen. If you want to simulate parallel stereo, set this to infinity.

Note that this creates an off-axis frustum, which means that the lenses are still pointing in the same direction, which is usually more desirable than the more naive toe-in approach, where the two lenses are simply tilted toward each other.

Prior to Panda3D 1.9.0, the convergence was being calculated incorrectly. It has since been corrected. To restore the legacy behavior you can set the stereo-lens-old-convergence variable to true.

Also see set_interocular_distance(), which relates.

◆ setCoordinateSystem()

setCoordinateSystem ( CoordinateSystem  cs)

Specifies the coordinate system that all 3-d computations are performed within for this Lens.

Normally, this is CS_default.

◆ setCustomFilmMat()

setCustomFilmMat ( const LMatrix4  custom_film_mat)

Specifies a custom matrix to transform the points on the film after they have been converted into nominal film space (-1 .

. 1 in U and V). This can be used to introduce arbitrary scales, rotations, or other linear transforms to the media plane. This is normally a 2-d matrix, but a full 4x4 matrix may be specified. This is applied on top of any film size, lens shift, and/or keystone correction.

◆ setFar()

setFar ( float  far_distance)

Defines the position of the far plane (or cylinder, sphere, whatever).

Points farther from the lens than this may not be rendered.

◆ setFilmOffset() [1/2]

setFilmOffset ( const LVecBase2  film_offset)

Sets the horizontal and vertical offset amounts of this Lens.

These are both in the same units specified in set_film_size().

This can be used to establish an off-axis lens.

◆ setFilmOffset() [2/2]

setFilmOffset ( float  x,
float  y 
)

Sets the horizontal and vertical offset amounts of this Lens.

These are both in the same units specified in set_film_size().

This can be used to establish an off-axis lens.

◆ setFilmSize() [1/3]

setFilmSize ( const LVecBase2  film_size)

Sets the size and shape of the "film" within the lens.

This both establishes the units used by calls like set_focal_length(), and establishes the aspect ratio of the frame.

In a physical camera, the field of view of a lens is determined by the lens' focal length and by the size of the film area exposed by the lens. For instance, a 35mm camera exposes a rectangle on the film about 24mm x 36mm, which means a 50mm lens gives about a 40-degree horizontal field of view.

In the virtual camera, you may set the film size to any units here, and specify a focal length in the same units to simulate the same effect. Or, you may ignore this parameter, and specify the field of view and aspect ratio of the lens directly.

◆ setFilmSize() [2/3]

setFilmSize ( float  width)

Sets the horizontal size of the film without changing its shape.

The aspect ratio remains unchanged; this computes the vertical size of the film to automatically maintain the aspect ratio.

◆ setFilmSize() [3/3]

setFilmSize ( float  width,
float  height 
)

Sets the size and shape of the "film" within the lens.

This both establishes the units used by calls like set_focal_length(), and establishes the aspect ratio of the frame.

In a physical camera, the field of view of a lens is determined by the lens' focal length and by the size of the film area exposed by the lens. For instance, a 35mm camera exposes a rectangle on the film about 24mm x 36mm, which means a 50mm lens gives about a 40-degree horizontal field of view.

In the virtual camera, you may set the film size to any units here, and specify a focal length in the same units to simulate the same effect. Or, you may ignore this parameter, and specify the field of view and aspect ratio of the lens directly.

◆ setFocalLength()

setFocalLength ( float  focal_length)

Sets the focal length of the lens.

This may adjust the field-of-view correspondingly, and is an alternate way to specify field of view.

For certain kinds of lenses (e.g. OrthographicLens), the focal length has no meaning.

◆ setFov() [1/3]

setFov ( const LVecBase2  fov)

Sets the field of view of the lens in both dimensions.

This establishes both the field of view and the aspect ratio of the lens. This is one way to specify the field of view of a lens; set_focal_length() is another way.

For certain kinds of lenses (like OrthographicLens), the field of view has no meaning.

◆ setFov() [2/3]

setFov ( float  fov)

Sets the horizontal field of view of the lens without changing the aspect ratio.

The vertical field of view is adjusted to maintain the same aspect ratio.

◆ setFov() [3/3]

setFov ( float  hfov,
float  vfov 
)

Sets the field of view of the lens in both dimensions.

This establishes both the field of view and the aspect ratio of the lens. This is one way to specify the field of view of a lens; set_focal_length() is another way.

For certain kinds of lenses (like OrthoLens), the field of view has no meaning.

◆ setFrustumFromCorners()

setFrustumFromCorners ( const LVecBase3  ul,
const LVecBase3  ur,
const LVecBase3  ll,
const LVecBase3  lr,
int  flags 
)

Sets up the lens to use the frustum defined by the four indicated points.

This is most useful for a PerspectiveLens, but it may be called for other kinds of lenses as well.

The frustum will be rooted at the origin (or by whatever translation might have been specified in a previous call to set_view_mat).

It is legal for the four points not to be arranged in a rectangle; if this is the case, the frustum will be fitted as tightly as possible to cover all four points.

The flags parameter contains the union of one or more of the following bits to control the behavior of this function:

FC_roll - If this is included, the camera may be rotated so that its up vector is perpendicular to the top line. Otherwise, the standard up vector is used.

FC_camera_plane - This allows the camera plane to be adjusted to be as nearly perpendicular to the center of the frustum as possible. Without this bit, the orientation camera plane is defined by position of the four points (which should all be coplanar). With this bit, the camera plane is arbitarary, and may be chosen so that the four points do not themselves lie in the camera plane (but the points will still be within the frustum).

FC_off_axis - This allows the resulting frustum to be off-axis to get the tightest possible fit. Without this bit, the viewing axis will be centered within the frustum, but there may be more wasted space along the edges.

FC_aspect_ratio - This allows the frustum to be scaled non-proportionately in the vertical and horizontal dimensions, if necessary, to get a tighter fit. Without this bit, the current aspect ratio will be preserved.

FC_shear - This allows the frustum to be sheared, if necessary, to get the tightest possible fit. This may result in a parallelogram-based frustum, which will give a slanted appearance to the rendered image. Without this bit, the frustum will be rectangle-based.

In general, if 0 is passed in as the value for flags, the generated frustum will be a loose fit but sane; if -1 is passed in, it will be a tighter fit and possibly screwy.

◆ setInterocularDistance()

setInterocularDistance ( float  interocular_distance)

Sets the distance between the left and right eyes of a stereo camera.

This distance is used to apply a stereo effect when the lens is rendered on a stereo display region. It only has an effect on a PerspectiveLens.

The left eye and the right eye are each offset along the X axis by half of this distance, so that this parameter specifies the total distance between them.

Also see set_convergence_distance(), which relates.

◆ setKeystone()

setKeystone ( const LVecBase2  keystone)

Indicates the ratio of keystone correction to perform on the lens, in each of three axes.

This will build a special non-affine scale factor into the projection matrix that will compensate for keystoning of a projected image; this can be used to compensate for a projector that for physical reasons cannot be aimed directly at its screen.

The default value is taken from the default-keystone Config variable. 0, 0 indicates no keystone correction; specify a small value (usually in the range -1 .. 1) in either the x or y position to generate a keystone correction in that axis.

◆ setMinFov()

setMinFov ( float  min_fov)

Sets the field of view of the smallest dimension of the window.

If the window is wider than it is tall, this specifies the vertical field of view; if it is taller than it is wide, this specifies the horizontal field of view.

In many cases, this is preferable to setting either the horizontal or vertical field of view explicitly. Setting this parameter means that pulling the window wider will widen the field of view, which is usually what you expect to happen.

◆ setNear()

setNear ( float  near_distance)

Defines the position of the near plane (or cylinder, sphere, whatever).

Points closer to the lens than this may not be rendered.

◆ setNearFar()

setNearFar ( float  near_distance,
float  far_distance 
)

Simultaneously changes the near and far planes.

◆ setViewHpr() [1/2]

setViewHpr ( const LVecBase3  view_hpr)

Sets the direction in which the lens is facing.

Normally, this is down the forward axis (usually the Y axis), but it may be rotated. This is only one way of specifying the rotation; you may also specify an explicit vector in which to look, or you may give a complete transformation matrix.

◆ setViewHpr() [2/2]

setViewHpr ( float  h,
float  p,
float  r 
)

Sets the direction in which the lens is facing.

Normally, this is down the forward axis (usually the Y axis), but it may be rotated. This is only one way of specifying the rotation; you may also specify an explicit vector in which to look, or you may give a complete transformation matrix.

◆ setViewMat()

setViewMat ( const LMatrix4  view_mat)

Sets an arbitrary transformation on the lens.

This replaces the individual transformation components like set_view_hpr().

Setting a transformation here will have a slightly different effect than putting one on the LensNode that contains this lens. In particular, lighting and other effects computations will still be performed on the lens in its untransformed (facing forward) position, but the actual projection matrix will be transformed by this matrix.

◆ setViewVector() [1/2]

setViewVector ( const LVector3  view_vector,
const LVector3  up_vector 
)

Specifies the direction in which the lens is facing by giving an axis to look along, and a perpendicular (or at least non-parallel) up axis.

See also set_view_hpr().

◆ setViewVector() [2/2]

setViewVector ( float  x,
float  y,
float  z,
float  i,
float  j,
float  k 
)

Specifies the direction in which the lens is facing by giving an axis to look along, and a perpendicular (or at least non-parallel) up axis.

See also set_view_hpr().

◆ write()

write ( Ostream  out,
int  indent_level 
)

Member Data Documentation

◆ aspect_ratio

float aspect_ratio

Returns the aspect ratio of the Lens.

This is determined based on the indicated film size; see set_film_size().

◆ change_event

const String change_event

Returns the name of the event that will be generated whenever any properties of this particular Lens have changed.

◆ convergence_distance

float convergence_distance

See set_convergence_distance().

◆ coordinate_system

CoordinateSystem coordinate_system

Returns the coordinate system that all 3-d computations are performed within for this Lens.

Normally, this is CS_default.

◆ far

float far

Returns the position of the far plane (or cylinder, sphere, whatever).

◆ film_offset

const LVector2 film_offset

Returns the horizontal and vertical offset amounts of this Lens.

See set_film_offset().

◆ film_size

const LVecBase2 film_size

Returns the horizontal and vertical film size of the virtual film.

See set_film_size().

◆ focal_length

float focal_length

Returns the focal length of the lens.

This may have been set explicitly by a previous call to set_focal_length(), or it may be computed based on the lens' fov and film_size. For certain kinds of lenses, the focal length has no meaning.

◆ fov

const LVecBase2 fov

Returns the horizontal and vertical film size of the virtual film.

See set_fov().

◆ interocular_distance

float interocular_distance

See set_interocular_distance().

◆ keystone

const LVecBase2 keystone

Returns the keystone correction specified for the lens.

◆ min_fov

float min_fov

Returns the field of view of the narrowest dimension of the window.

See set_min_fov().

◆ near

float near

Returns the position of the near plane (or cylinder, sphere, whatever).

◆ nodal_point

LPoint3 nodal_point

Returns the center point of the lens: the point from which the lens is viewing.

◆ view_hpr

const LVecBase3 view_hpr

Returns the direction in which the lens is facing.

◆ view_mat

const LMatrix4 view_mat

Returns the direction in which the lens is facing.