vesta_variables

vesta_variables

Commonly used variable types for state estimation in factor graph optimization. All variables derive from vesta_core::Variable and support Boost serialization for persistence and polymorphic deserialization.

Architecture

Variables are organized into four subdirectories by domain:

• 2d/ -- Planar state variables (position, orientation, velocity, acceleration)
• 3d/ -- Spatial state variables (position, orientation, velocity, acceleration, IMU biases)
• vision/ -- Camera intrinsic models and visual landmarks
• common/ -- Base classes and mixins shared across variable types

Most variables inherit from two base classes via multiple inheritance:

• FixedSizeVariable<N> -- Provides a compile-time-sized std::array<double, N> for the variable's parameter block
• Stamped -- Adds a timestamp and device ID for time-varying quantities

Vision variables (cameras and landmarks) are not stamped, as they represent quantities that persist across time.

Include Convention

#include <vesta_variables/2d/position_2d_stamped.h>
#include <vesta_variables/3d/orientation_3d_stamped.h>
#include <vesta_variables/vision/pinhole_camera.h>
#include <vesta_variables/common/fixed_size_variable.h>

Variable Reference

Common (common/)

Class	Header	Description
FixedSizeVariable<N>	common/fixed_size_variable.h	Template base class providing a statically-sized std::array<double, N> parameter block. Implements Variable::data() and Variable::size().
Stamped	common/stamped.h	Mixin base class that associates a timestamp and device UUID with a variable. Used via multiple inheritance for time-varying quantities.

2D Variables (2d/)

All 2D variables inherit from both FixedSizeVariable<N> and Stamped.

Class	Header	Size	Parameters	Description
Position2DStamped	2d/position_2d_stamped.h	2	x, y	2D position in a plane
Orientation2DStamped	2d/orientation_2d_stamped.h	1	yaw	2D heading angle with custom manifold for angle wrapping
VelocityLinear2DStamped	2d/velocity_linear_2d_stamped.h	2	vx, vy	2D linear velocity
VelocityAngular2DStamped	2d/velocity_angular_2d_stamped.h	1	vyaw	2D angular velocity (yaw rate)
AccelerationLinear2DStamped	2d/acceleration_linear_2d_stamped.h	2	ax, ay	2D linear acceleration
AccelerationAngular2DStamped	2d/acceleration_angular_2d_stamped.h	1	ayaw	2D angular acceleration

The Orientation2DStamped variable provides a custom Orientation2DManifold that handles the 2*pi angle wrapping discontinuity.

3D Variables (3d/)

All 3D variables inherit from both FixedSizeVariable<N> and Stamped.

Class	Header	Size	Parameters	Description
Position3DStamped	3d/position_3d_stamped.h	3	x, y, z	3D position
Orientation3DStamped	3d/orientation_3d_stamped.h	4	w, x, y, z	3D orientation as a quaternion (tangent size 3) with custom manifold
VelocityLinear3DStamped	3d/velocity_linear_3d_stamped.h	3	vx, vy, vz	3D linear velocity
VelocityAngular3DStamped	3d/velocity_angular_3d_stamped.h	3	vroll, vpitch, vyaw	3D angular velocity
AccelerationLinear3DStamped	3d/acceleration_linear_3d_stamped.h	3	ax, ay, az	3D linear acceleration
AccelerationAngular3DStamped	3d/acceleration_angular_3d_stamped.h	3	aroll, apitch, ayaw	3D angular acceleration
AccelerationBias3DStamped	3d/acceleration_bias_3d_stamped.h	3	bx, by, bz	Accelerometer bias for IMU modeling
GyroscopeBias3DStamped	3d/gyroscope_bias_3d_stamped.h	3	bx, by, bz	Gyroscope bias for IMU modeling

The Orientation3DStamped variable uses a quaternion representation (w, x, y, z) with an Orientation3DManifold that applies angle-axis updates via Rodrigues formula. The ambient size is 4 but the tangent size is 3, reflecting the true degrees of freedom.

Vision Variables (vision/)

Camera Models

Camera variables inherit from BaseCamera<N> and are identified by a camera ID rather than a timestamp. Fixed variants override holdConstant() to prevent optimization of intrinsic parameters.

Class	Header	Size	Parameters	Description
BaseCamera<N>	vision/base_camera.h	N	(template)	Template base class for camera intrinsic variables, identified by camera ID
PinholeCamera	vision/pinhole_camera.h	4	fx, fy, cx, cy	Standard pinhole camera intrinsics (optimizable)
PinholeCameraFixed	vision/pinhole_camera_fixed.h	4	fx, fy, cx, cy	Pinhole camera intrinsics held constant during optimization
PinholeCameraRadial	vision/pinhole_camera_radial.h	3	f, r1, r2	Pinhole camera with shared focal length and two radial distortion coefficients
StereoCamera	vision/stereo_camera.h	5	fx, fy, cx, cy, baseline	Stereo camera intrinsics including baseline distance (optimizable)
StereoCameraFixed	vision/stereo_camera_fixed.h	5	fx, fy, cx, cy, baseline	Stereo camera intrinsics held constant during optimization

Landmark Variables

Landmark variables represent persistent spatial features identified by a landmark ID. They are not stamped since landmarks exist across time. Fixed variants hold the landmark position constant during optimization. Landmarks return Schur group 0 for efficient elimination in Schur complement-based solvers.

Class	Header	Size	Parameters	Description
Point2DLandmark	vision/point_2d_landmark.h	2	x, y	2D point landmark (optimizable)
Point2DFixedLandmark	vision/point_2d_fixed_landmark.h	2	x, y	2D point landmark held constant during optimization
Point3DLandmark	vision/point_3d_landmark.h	3	x, y, z	3D point landmark (optimizable)
Point3DFixedLandmark	vision/point_3d_fixed_landmark.h	3	x, y, z	3D point landmark held constant during optimization