Properties: Rigid Body

Rigid Body Properties

General Properties

Create From Visible: Creates a rigid body out of all visible, unassigned markers on the screen.

Create From Selection: Creates a rigid body from all selected markers.

Name: Allows a custom name to be assigned to the rigid body. Default is "Rigid Body X" where x is the Rigid Body ID.

Rigid Body ID: Assigns a numeric Identifier to the Rigid Body. Default is the lowest available positive whole number.

Color: Selects a color for the rigid body in the 3D Perspective View. Color is a standard RGB triplet.

Display Options

Label: Selects whether or not to display the rigid body name in the 3D Perspective View. If selected, a small label in the same color as the rigid body will appear over the centroid in the 3D Perspective View.

Tracked: Selects whether or not to show the rigid body in the 3D Perspective View when it is tracked.

Untracked: Selects whether or not to show the last known position of a rigid body in the 3D Perspective View after tracking has been lost. If enabled, the rigid body will appear somewhat remain frozen in the last known position before tracking was lost, until tracking is regained.

Pivot: Selects whether the pivot point of the rigid body is displayed.

Untracked Markers: When enabled, all markers that are part of the rigid body definition will be dimmed, but still visible, when not present in the point cloud.

Quality: Enabling will turn the connecting lines between markers in a rigid body red as the distance between the markers deviates from what was defined during the rigid body creation.

Marker Quality: Enables ranking of markers and highlights those with higher residuals in red. This setting can be useful in determining marker detection quality and troubleshooting issues based on detection.

Orientation: Enables the display of a rigid body's local coordinate axes. This option can be useful in visualizing the orientation of the rigid body, and for setting orientation offsets.

Model Replace: Enables replacing the rigid body visualization with a valid OBJ model.

OBJ Model: Specifies the path and filename for an OBJ model to replace the standard rigid body visualization. The standard visualization will be used if Model Replace is set to True, but no information is entered into the OBJ Model field.

Scale: Changes the size of the OBJ Model. Default is 1.

Yaw/Pitch/Roll: Offsets the orientation of the OBJ Model relative to the pivot point of the rigid body to correct for orientation discrepancies.

X/Y/Z: Offsets the translation the position of the OBJ Model relative to the pivot point of the rigid body.

Solver Settings

Enabled: Toggles solving for the selected rigid body on and off.

Max Marker Deflection: The maximum distance in millimeters that a marker may deviate from its expected position before it is not considered as part of the rigid body. Lower deflection settings force the solver to be more strict with marker positions, creating a more accurate solve, but with higher risk of gaps in the data. Higher deflection settings can allow for more continuous data, but with the potential for less accuracy in the rigid body solve.

Min Marker Count: The minimum number of markers required to solve and track the rigid body. Default is dependent on number of markers in the rigid body. At minimum, 3 markers are required to accurately determine position and orientation of the rigid body. Increasing this can help to prevent improper solutions in environments with high marker counts, though it will make the Rigid body more prone to remaining unsolved if markers are occluded from camera view.

Min Hit Count: The minimum number of marker to marker distance checks that must succeed within the defined flexibility range to consider a rigid body solved. Adjusting this can be useful in creating more or less stringent solution requirements, depending on your environment and the elasticity of the object being tracked. A lower number will be better for higher elasticity objects, and a higher number will be better for ensuring the accuracy of more rigid objects. Default is dependent on number of markers in the rigid body.

Flexibility: The amount a rigid body is allowed to deform to fit the available point cloud. A lower number will allow less flex in the rigid body shape to fit the markers in the point cloud. Valid range is 0 to 100, Default 50.

Share Markers: Allows markers for this rigid body to be shared with other rigid bodies. In order for two rigid bodies to share markers, both must have this option set to true. Enable this only if the same marker is used in multiple rigid bodies as a pivot point.

Dynamic Override: Override dynamic constraints after this many frames and allow a solution that was previously rejected by the dynamic constraint conditions. A value of 0 will disable Dynamic Override. Default is 100.

Static Override: Override static constraints after this many frames and allow a solution that was previously rejected by the static constraint conditions. A value of 0 will disable Static Override. Default is 0.

Precise Orientation: Allows the user to enable more precise orientation solving at the cost of increased CPU usage. Disabling this will reduce the quality of orientation values, but can decrease system load. Valid options are: True (enabled) (default), False (disabled)

Force Exhaustive: Forces a complete search of the Point Cloud for the best possible match of this rigid body, even after a potential match has already been found. Enabling this can assist in preventing false positives for the rigid body, but at the cost of performance.

Calculation Time: Defines the maximum amount of time in milliseconds that can be spent searching for the rigid body. If the rigid body is not found in this time, it will be abandoned for the frame. Decreasing this value can assist if latency values begin to rise. Default is 5.

Acquisition Delay: Defines the number of frames to wait between search attempts for the rigid body when it is in the untracked state. Increasing this value can delay the finding of a rigid body, but will assist in reducing the performance hit caused by a high calculation time in high marker environments. Default is 1.

Display History

Position History: Shows a history of the rigid body’s position.

Orientation History: Shows a history of the rigid body’s orientation.

History Length: Selects the number of frames’ worth of position or orientation history that is displayed when either option is turned on. Valid range is 1 to 1000. Default is 500.

Orientation Spread: Sets the number of frames between orientation history markers in the 3D Perspective View. Increasing this value will cause the markers to appear less frequently, which can improve visualization if the object is rotating at a slower pace. Valid range is 1 to 100. Default is 10.

Orientation Size: Sets the size of the orientation history icon in the 3D Perspective View. Valid range is 1 to 100. Default is 10.

Smoothing Settings

Translation: Applies a Kalman filter to translation data. Increasing can smooth out noise in the rigid body data, but excessive smoothing can introduce lag. Valid range is 0 to 1. Default is 0 (disabled).

Rotation: Applies a Kalman filter to rotation data. Increasing can smooth out noise in the rigid body data, but excessive smoothing can introduce lag. Valid range is 0 to 1. Default is 0 (disabled).

Marker Locations

Lists X, Y, and Z marker positions for each marker in the rigid body, relative to the center of the rigid body. These positions can be manually entered, if precise marker locations are known in advance.

Dynamic Constraints

Enable to limit the maximum rotation or translation of a rigid body from one frame to the next. By default, moderate dynamic constraints are in place to prevent erratic behavior (e.g. rigid body “flipping”) in the rigid body solve. Creating stricter constraints can provide even more protection, while loosening constraints can assist when tracking very fast moving objects.

Translation

Enforce: Enables dynamic constraints on the translation of the rigid body.

Max Translation/Frame: The maximum distance in millimeters that a rigid body can travel between two frames before the solver considers it invalid. Raising this will allow dynamic constraints to consider faster movement valid. Default is 100.

Rotation

Enforce: Enables dynamic constraints on the rotation of the rigid body.

Max Rotation/Frame: The maximum number of degrees a rigid body can rotate between two frames before the solver considers it invalid. Raising this will allow dynamic constraints to consider faster rotation valid. Default is 30.

Static Constraints

Enable to constrain maximum rigid body yaw, pitch, or roll—relative to the global coordinate plane—for the given rigid body. Static constraints can help provide stability to the rigid body solve when the tracked object is only expected to rotate within a specific range of orientation. Defaults for each are False (disabled), -90 and 90 (full rotation allowed).

Rigid body Engine Statistics

Defined Rigid Bodies: The total number of rigid bodies defined by the system, whether they are currently tracked or not.

Process Time: The total amount of time required by Motive to process and solve all rigid bodies.