Read AMC Motion Capture File (.amc)

Parses an Acclaim Motion Capture (AMC) file containing frame-by-frame joint angle data. AMC files store joint angles per frame, with each frame listing joint names followed by their DOF values. An optional ASF skeleton can be provided for validation and DOF mapping.

Usage

readAMC(path, asf = NULL, fps = 120)

Arguments

path

Character string giving the path to the .amc file.

asf

An ASFSkeleton object (from readASF()), or NULL. If provided, used for DOF validation and enriched metadata.

fps

Numeric frame rate in Hz. AMC files do not store frame rate, so this must be specified (default: 120).

Value

A PhysioExperiment object with:

assays

rotation_x, rotation_y, rotation_z for all joints; position_x, position_y, position_z for the root joint only.

colData

DataFrame with label (joint names), type ("root" or "joint"), and dof_count (number of DOFs).

metadata

List with asf_skeleton (if provided), source_file, and units (from ASF if provided).

samplingRate

Set to fps.

References

CMU Graphics Lab (2003). "CMU Motion Capture Database." http://mocap.cs.cmu.edu/.

See also

readASF() for reading skeleton definitions in ASF format, readMoCapCSV() for reading motion capture data from CSV files.

Examples

asf_file <- system.file("testdata", "sample.asf", package = "PhysioMoCap")
amc_file <- system.file("testdata", "sample.amc", package = "PhysioMoCap")
if (nzchar(asf_file) && nzchar(amc_file)) {
  skel <- readASF(asf_file)
  pe <- readAMC(amc_file, asf = skel)
  pe
}
#> class: PhysioExperiment
#> dim: 3 x 3 
#> assays(6): rotation_x, rotation_y, rotation_z ...
#> samplingRate: 120 Hz
#> channels(3): root, lfemur, ltibia
#> colData names(3): label, type, dof_count