sim3d.sensors.Camera
Description
Use the sim3d.sensors.Camera object to create a camera with a lens in
the 3D environment. The sensor is based on the ideal pinhole camera model, with a lens added
to represent a full camera model, including lens distortion. This camera object supports a
field of view of up to 150 degrees. For more details, see Algorithms. After you create a
sim3d.sensors.Camera object, you can modify aspects of the actor object by setting
property values.
Creation
Description
camera = sim3d.sensors.Camera()sim3d.sensors.Camera object in the 3D environment.
camera = sim3d.sensors.Camera(Name=Value)HorizontalFieldOfView to
60.
Input Arguments
Specify optional pairs of arguments as
Name1=Value1,...,NameN=ValueN, where Name is
the argument name and Value is the corresponding value.
Name-value arguments must appear after other arguments, but the order of the
pairs does not matter.
Example: camera =
sim3d.sensors.Camera(ActorName=Camera,ImageSize=[768,1024],FocalLength=[1109,1109])
These intrinsic camera properties are equivalent to the properties of a cameraIntrinsics (Computer Vision Toolbox) object. To obtain the intrinsic properties for your camera,
use the Camera Calibrator app.
For details about the camera calibration process, see Using the Single Camera Calibrator App (Computer Vision Toolbox) and What Is Camera Calibration? (Computer Vision Toolbox).
ActorName — Name of actor
autogenerated name (default) | character array | string
Name of actor, specified as a character array or string. If you do not specify an actor name,
then the software assigns the actor an autogenerated name. Use
this argument to set the name of the
sim3d.sensors.Camera object.
Note
If you specify the same name as an actor that already exists, then the software appends actor name you specify with a unique identifier.
Translation — Relative translation
[0,0,0] (default) | real 1-by-3 vector
Relative translation
(x,y,z) of the actor object to its
parent actor, specified as a real 1-by-3 vector, in m. Use Translation to
change the position of the sim3d.sensors.Camera object in the 3D environment along the
X, Y, and Z axes of the
coordinate system. When you add an actor to the 3D environment, the default parent actor is the
Scene Origin at (0,0,0).
Example: Translation=[1 2 1]
Rotation — Relative rotation
[0,0,0] (default) | real 1-by-3 vector
Relative rotation (roll,
pitch, yaw) of the actor object to its parent actor,
specified as a real 1-by-3 vector, in rad. Use Rotation to rotate the
sim3d.sensors.Camera object in the 3D environment.
Example: Rotation=[pi/4 pi/8 pi/2]
FocalLength — Focal length of camera
[1109,1109] (default) | real-valued 1-by-2 vector of positive integers
Focal length of camera, specified as a real-valued 1-by-2 vector of positive integers of the form [fx, fy], in pixels.
fx = F × sx
fy = F × sy
where:
F is the focal length in world units, typically millimeters.
[sx, sy] are the number of pixels per world unit in the x and y direction, respectively.
FocalLength is equivalent to the FocalLength (Computer Vision Toolbox) property
of a cameraIntrinsics object.
OpticalCenter — Optical center of camera
[640,360] (default) | real-valued 1-by-2 vector of positive integers
Optical center of camera, specified as a real-valued 1-by-2
vector of positive integers of the form [cx,cy], in
pixels. OpticalCenter is equivalent to the PrincipalPoint (Computer Vision Toolbox)
property of a cameraIntrinsics object.
ImageSize — Image size produced by camera
[768,1024] (default) | real-valued 1-by-2 vector of positive integers
Image size produced by the sim3d.sensors.Camera
object, specified as a real-valued 1-by-2 vector of positive integers of the form
[m,n], in pixels. ImageSize is
equivalent to the ImageSize (Computer Vision Toolbox) property of a
cameraIntrinsics object.
RadialDistortionCoefficients — Radial distortion coefficients
[0,0] (default) | real-valued 2-element vector | real-valued 3-element vector | real-valued 6-element vector
Radial distortion coefficients, specified as a real-valued 2-element, 3-element, or 6-element vector. Radial distortion is the displacement of image points along radial lines extending from the principal point.
As the image points move away from the principal point (positive radial displacement), image magnification decreases, and a pincushion-shaped distortion occurs on the image.
As the image points move toward the principal point (negative radial displacement), image magnification increases, and a barrel-shaped distortion occurs on the image.
The camera sensor calculates the (xd,yd) radial-distorted location of a point using a two-coefficient, three-coefficient, or six-coefficient formula. This table shows the formulas, where:
(x,y) = undistorted pixel locations
k1,k2,k3,k4,k5,k6 = radial distortion coefficients of the lens
r2 = x2 + y2
| Coefficients | Formula | Description |
[k1, k2] |
xd = x(1 + k1r2 + k2r4) yd = y(1 + k1r2 + k2r4) | This model is equivalent to the two-coefficient model used by the
RadialDistortion (Computer Vision Toolbox) property of a
cameraIntrinsics object. |
[k1, k2, k3] |
xd = x(1 + k1r2 + k2r4 + k3r6) yd = y(1 + k1r2 + k2r4 + k3r6) | This model is equivalent to the three-coefficient model used by the
RadialDistortion (Computer Vision Toolbox) property of a
cameraIntrinsics object. |
[k1, k2, k3, k4, k5, k6] | The six-coefficient model is based on the OpenCV radial distortion model. Note The Camera Calibrator app does not support this model. To calibrate a camera using this model, see Camera Calibration and 3D Reconstruction in the OpenCV documentation. |
TangentialDistortionCoefficients — Tangential distortion coefficients
[0,0] (default) | real-valued 2-element vector
Tangential distortion coefficients, specified as a real-valued 2-element vector. Tangential distortion occurs when the lens and the image plane are not parallel.
The camera sensor calculates the tangential distorted location of a point, (xd, yd), using this formula:
xd = x + [2p1xy + p2 × (r2 + 2x2)]
yd = y + [p1 × (r2 + 2y2) + 2p2xy]
where:
x, y = undistorted pixel locations
p1, p2 = tangential distortion coefficients of the lens
r2 = x2 + y2
The undistorted pixel locations appear in normalized image coordinates, with the origin at the optical center. The coordinates are expressed in world units. TangentialDistortionCoefficients is equivalent to the TangentialDistortion (Computer Vision Toolbox) property of a cameraIntrinsics object.
Skew — Skew angle of camera axes
0 (default) | nonnegative real-valued scalar
Skew angle of camera axes, specified as a nonnegative real-valued scalar. If the X-axis and Y-axis are exactly perpendicular, then the skew must be 0. Units are dimensionless. Skew is equivalent to the Skew (Computer Vision Toolbox) property of a cameraIntrinsics object.
EnableDepthOutput — Option to enable depth output
0 or false (default) | 1 or true
Option to enable depth output, specified as 0
(false) if depth output is not enabled or 1
(true) if it is enabled.
Example: EnableDepthOutput=1
EnableSemanticOutput — Option to enable semantic output
0 or false (default) | 1 or true
Option to enable semantic output, specified as 0
(false) if semantic output is not enabled or
1 (true) if it is enabled.
Example: EnableSemanticOutput=1
Properties
Parent — Parent of actor
handle to parent actor object
Parent of actor, specified as a handle to the parent actor
object. After you add an actor to the sim3d.World object, the default parent
actor is the Scene Origin at (0,0,0). Use
Parent to set any actor in the 3D environment as the parent actor of a
sim3d.sensors.Camera object.
Children — Children of actor
structure
This property is read-only.
Children of actor, specified as a structure. Each field of the structure contains a handle to
the child of a sim3d.sensors.Camera object.
ParentWorld — Parent world
handle to parent world object
Parent world, specified as a handle to the parent sim3d.World
object. You can use this property only if the sim3d.sensors.Camera object is
added to the parent sim3d.World object.
SensorIdentifier — Unique ID of sensor
real positive scalar
This property is read-only.
Unique ID of the sensor, specified as a real positive scalar.
Data Types: uint32
Translation — Relative translation
[0,0,0] (default) | real 1-by-3 vector
Relative translation
(x,y,z) of the actor object to its
parent actor, specified as a real 1-by-3 vector, in m. Use Translation to
change the position of the sim3d.sensors.Camera object in the 3D environment along the
X, Y, and Z axes of the
coordinate system. When you add an actor to the 3D environment, the default parent actor is the
Scene Origin at (0,0,0).
Example: camera.Translation = [1 2 1]
Rotation — Relative rotation
[0,0,0] (default) | real 1-by-3 vector
Relative rotation (roll,
pitch, yaw) of the actor object to its parent actor,
specified as a real 1-by-3 vector, in rad. Use Rotation to rotate the
sim3d.sensors.Camera object in the 3D environment.
Example: camera.Rotation = [pi/4 pi/8 pi/2]
Mobility — Type of actor mobility
'sim3d.utils.MobilityTypes.Static' (default) | 'sim3d.utils.MobilityTypes.Movable'
Type of actor mobility to respond to physics, move the actor
during simulation, or both, specified as 'sim3d.utils.MobilityTypes.Movable'
or 'sim3d.utils.MobilityTypes.Static'.
Example: camera.Mobility =
sim3d.utils.MobilityTypes.Movable
Data Types: sim3d.utils.MobilityTypes
FocalLength — Focal length of camera
[1109,1109] (default) | real-valued 1-by-2 vector of positive integers
Focal length of camera, specified as a real-valued 1-by-2 vector of positive integers of the form [fx, fy], in pixels.
fx = F × sx
fy = F × sy
where:
F is the focal length in world units, typically millimeters.
[sx, sy] are the number of pixels per world unit in the x and y direction, respectively.
FocalLength is equivalent to the FocalLength (Computer Vision Toolbox) property
of a cameraIntrinsics object.
OpticalCenter — Optical center of camera
[640,360] (default) | real-valued 1-by-2 vector of positive integers
Optical center of camera, specified as a real-valued 1-by-2
vector of positive integers of the form [cx,cy], in
pixels. OpticalCenter is equivalent to the PrincipalPoint (Computer Vision Toolbox)
property of a cameraIntrinsics object.
ImageSize — Image size produced by camera
[768,1024] (default) | real-valued 1-by-2 vector of positive integers
Image size produced by the sim3d.sensors.Camera
object, specified as a real-valued 1-by-2 vector of positive integers of the form
[m,n], in pixels. ImageSize is
equivalent to the ImageSize (Computer Vision Toolbox) property of a
cameraIntrinsics object.
RadialDistortionCoefficients — Radial distortion coefficients
[0,0] (default) | real-valued 2-element vector | real-valued 3-element vector | real-valued 6-element vector
Radial distortion coefficients, specified as a real-valued 2-element, 3-element, or 6-element vector. Radial distortion is the displacement of image points along radial lines extending from the principal point.
As the image points move away from the principal point (positive radial displacement), image magnification decreases, and a pincushion-shaped distortion occurs on the image.
As the image points move toward the principal point (negative radial displacement), image magnification increases, and a barrel-shaped distortion occurs on the image.
The camera sensor calculates the (xd,yd) radial-distorted location of a point using a two-coefficient, three-coefficient, or six-coefficient formula. This table shows the formulas, where:
(x,y) = undistorted pixel locations
k1,k2,k3,k4,k5,k6 = radial distortion coefficients of the lens
r2 = x2 + y2
| Coefficients | Formula | Description |
[k1, k2] |
xd = x(1 + k1r2 + k2r4) yd = y(1 + k1r2 + k2r4) | This model is equivalent to the two-coefficient model used by the
RadialDistortion (Computer Vision Toolbox) property of a
cameraIntrinsics object. |
[k1, k2, k3] |
xd = x(1 + k1r2 + k2r4 + k3r6) yd = y(1 + k1r2 + k2r4 + k3r6) | This model is equivalent to the three-coefficient model used by the
RadialDistortion (Computer Vision Toolbox) property of a
cameraIntrinsics object. |
[k1, k2, k3, k4, k5, k6] | The six-coefficient model is based on the OpenCV radial distortion model. Note The Camera Calibrator app does not support this model. To calibrate a camera using this model, see Camera Calibration and 3D Reconstruction in the OpenCV documentation. |
TangentialDistortionCoefficients — Tangential distortion coefficients
[0,0] (default) | real-valued 2-element vector
Tangential distortion coefficients, specified as a real-valued 2-element vector. Tangential distortion occurs when the lens and the image plane are not parallel.
The camera sensor calculates the tangential distorted location of a point, (xd, yd), using this formula:
xd = x + [2p1xy + p2 × (r2 + 2x2)]
yd = y + [p1 × (r2 + 2y2) + 2p2xy]
where:
x, y = undistorted pixel locations
p1, p2 = tangential distortion coefficients of the lens
r2 = x2 + y2
The undistorted pixel locations appear in normalized image coordinates, with the origin at the optical center. The coordinates are expressed in world units. TangentialDistortionCoefficients is equivalent to the TangentialDistortion (Computer Vision Toolbox) property of a cameraIntrinsics object.
Skew — Skew angle of camera axes
0 (default) | nonnegative real-valued scalar
Skew angle of camera axes, specified as a nonnegative real-valued scalar. If the X-axis and Y-axis are exactly perpendicular, then the skew must be 0. Units are dimensionless. Skew is equivalent to the Skew (Computer Vision Toolbox) property of a cameraIntrinsics object.
Object Functions
read | Return image data captured with camera |
Algorithms
References
[1] Bouguet, Jean-Yves. Camera Calibration Toolbox for Matlab. CaltechDATA, 2022. https://doi.org/10.22002/D1.20164.
[2] Zhang, Zhengyou. "A Flexible New Technique for Camera Calibration." IEEE Transactions on Pattern Analysis and Machine Intelligence. 22, no. 11 (2000): 1330–34.
[3] Heikkilä, Janne, and Olli Silven. “A Four-Step Camera Calibration Procedure with Implicit Image Correction.” In Proceedings of IEEE International Conference on Computer Vision and Pattern Recognition. San Juan, PR, June 17–19, 1997: 1106–12. https://doi.org/10.1109/CVPR.1997.609468.
Version History
Introduced in R2024b
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