Random Variables¶

A set of random variables for sampling camera positions and rendering the scene from those positions.

CameraSample¶

class meshrender.CameraSample(camera_to_world_pose, camera_intr, radius, elev, az, roll, tx=0, ty=0, focal=0, cx=0, cy=0)¶

Bases: object

Struct to encapsulate the results of sampling a camera and its pose.

object_to_camera_pose¶: autolab_core.RigidTransform – A transfrom from the object frame to the camera frame.

camera_intr¶: perception.CameraIntrinsics – The camera’s intrinsics.

radius¶: float – The distance from the center of the object’s frame to the camera’s eye.

elev¶: float – The angle of elevation to the camera from the object frame.

az¶: float – The angle of rotation of the camera’s eye about the object’s z axis, starting from the x axis.

roll¶: float – The roll angle of the camera about its viewing axis.

tx¶: float – The x-axis translation of the object.

ty¶: float – The y-axis translation of the object.

focal¶: float – The focal length of the camera.

cx¶: float – The x-axis optical center of the camera.

cy¶: float – The y-axis optical center of the camera.

RenderSample¶

class meshrender.RenderSample(renders, camera)¶

Bases: object

Struct to encapsulate the results of sampling rendered images from a camera.

renders¶: dict – A dictionary mapping perception.RenderMode types to perception.Image classes.

camera¶: CameraSample – The camera sample that produced this render sample.

UniformViewsphereRandomVariable¶

class meshrender.UniformViewsphereRandomVariable(min_radius, max_radius, min_elev, max_elev, min_az=0, max_az=6.283185307179586, min_roll=0, max_roll=6.283185307179586, num_prealloc_samples=1)¶

Bases: autolab_core.random_variables.RandomVariable

Uniform distribution over a bounded region of a viewing sphere.

__init__(min_radius, max_radius, min_elev, max_elev, min_az=0, max_az=6.283185307179586, min_roll=0, max_roll=6.283185307179586, num_prealloc_samples=1)¶

Initialize a UniformViewsphereRandomVariable.

Parameters:

min_radius (float) – Minimum radius for viewing sphere.
max_radius (float) – Maximum radius for viewing sphere.
min_elev (float) – Minimum elevation (angle from z-axis) for camera position.
max_elev (float) – Maximum elevation for camera position.
min_az (float) – Minimum azimuth (angle from x-axis) for camera position.
max_az (float) – Maximum azimuth for camera position.
min_roll (float) – Minimum roll (rotation of camera about axis generated by azimuth and elevation) for camera.
max_roll (float) – Maximum roll for camera.
num_prealloc_samples (int) – Number of preallocated samples.

object_to_camera_pose(radius, elev, az, roll)¶: Convert spherical coords to an object-camera pose.

sample(size=1)¶

Sample random variables from the model.

Parameters:	size (int) – number of sample to take
Returns:	sampled object to camera poses
Return type:	`list` of `RigidTransform`

UniformPlanarWorksurfaceRandomVariable¶

class meshrender.UniformPlanarWorksurfaceRandomVariable(frame, config, num_prealloc_samples=1)¶

Bases: autolab_core.random_variables.RandomVariable

Uniform distribution over camera poses and intrinsics about a viewsphere over a planar worksurface. The camera is positioned pointing towards (0,0,0).

__init__(frame, config, num_prealloc_samples=1)¶

Initialize a UniformPlanarWorksurfaceRandomVariable.

Parameters:	frame (str) – string name of the camera frame config (autolab_core.YamlConfig) – configuration containing parameters of random variable num_prealloc_samples (int) – Number of preallocated samples.

Notes

Required parameters of config are specified in Other Parameters

Other Parameters:

focal_length (Focal length of the camera) – min : float max : float
delta_optical_center (Change in optical center from neutral.) – min : float max : float
radius (Distance from camera to world origin.) – min : float max : float
azimuth (Azimuth (angle from x-axis) of camera in degrees.) – min : float max : float
elevation (Elevation (angle from z-axis) of camera in degrees.) – min : float max : float
roll (Roll (angle about view direction) of camera in degrees.) – min : float max : float
x (Translation of world center in x axis.) – min : float max : float
y (Translation of world center in y axis.) – min : float max : float
im_height (float Height of image in pixels.)
im_width (float Width of image in pixels.)

camera_to_world_pose(radius, elev, az, roll, x, y)¶: Convert spherical coords to a camera pose in the world.

camera_intrinsics(T_camera_world, f, cx, cy)¶: Generate shifted camera intrinsics to simulate cropping.

sample(size=1)¶

Sample random variables from the model.

Parameters:	size (int) – number of sample to take
Returns:	sampled camera intrinsics and poses
Return type:	`list` of `CameraSample`

UniformPlanarWorksurfaceImageRandomVariable¶

class meshrender.UniformPlanarWorksurfaceImageRandomVariable(object_name, scene, render_modes, frame, config, num_prealloc_samples=0)¶

Bases: autolab_core.random_variables.RandomVariable

Random variable for sampling images from a camera positioned about an object on a table.

__init__(object_name, scene, render_modes, frame, config, num_prealloc_samples=0)¶

Initialize a UniformPlanarWorksurfaceImageRandomVariable.

Parameters:

object_name (str) – The name of the object to render views about
scene (Scene) – The scene to be rendered which contains the target object.
render_modes (list of perception.RenderMode) – A list of RenderModes that indicate the wrapped images to return.
frame (str) – The name of the camera’s frame of reference.
config (autolab_core.YamlConfig) – A configuration containing parameters of the random variable.
num_prealloc_samples (int) – Number of preallocated samples.

Notes

Required parameters of config are specified in Other Parameters.

Other Parameters:

focal_length (Focal length of the camera) – min : float max : float
delta_optical_center (Change in optical center from neutral.) – min : float max : float
radius (Distance from camera to world origin.) – min : float max : float
azimuth (Azimuth (angle from x-axis) of camera in degrees.) – min : float max : float
elevation (Elevation (angle from z-axis) of camera in degrees.) – min : float max : float
roll (Roll (angle about view direction) of camera in degrees.) – min : float max : float
x (Translation of world center in x axis.) – min : float max : float
y (Translation of world center in y axis.) – min : float max : float
im_height (float Height of image in pixels.)
im_width (float Width of image in pixels.)

sample(size=1, front_and_back=False)¶

Sample random variables from the model.

Parameters:	size (int) – Number of samples to take front_and_back (bool) – If True, all normals are treated as facing the camera
Returns:	A list of samples of renders taken with random camera poses about the scene. If size was 1, returns a single sample rather than a list.
Return type:	list of RenderSample