def _readHeader(self): ''' Read the header information from the BVH file. ''' assert self.bvhFile.tell() == 0, \ 'Must be at the start of file to read header' self._checkToken("HIERARCHY") self._checkToken("ROOT") self.model = SampledBodyModel() self.model.channels = [] self.jointStack = [] self.jointStack.append(self.model) self._readJoint() del self.jointStack self._checkToken("MOTION") self._checkToken("Frames:") self.frameCount = self._intToken() self._checkToken("Frame") self._checkToken("Time:") self.framePeriod = self._floatToken()
def testAgainstReality(): dir = path.dirname(__file__) filebase = path.join(dir, "swing") refbase = path.join(dir, "stand") magbases = [path.join(dir, f) for f in ['magsweep1', 'magsweep2']] maglookup = {'Upper Leg IMU': '66', 'Orient 8': '8', 'Orient 43': '43'} magSamples = 2000 refTime = 1.0 posStdDev = 0.0005 rotStdDev = 0.004 ref3D = SplinedMarkerCapture(loadQualisysTSVFile(refbase + "_3D.tsv"), positionStdDev=posStdDev) ref6D = SplinedMarkerCapture(loadQualisysTSVFile(refbase + "_6D.tsv"), rotationStdDev=rotStdDev) capture3D = SplinedMarkerCapture(loadQualisysTSVFile(filebase + "_3D.tsv"), positionStdDev=posStdDev) captureSD = SensorDataCapture.load(filebase + ".sdc") hip, thigh, knee, shin, ankle = \ ['Hip', 'Thigh', 'Knee Hinge', 'Shin', 'Ankle'] jointNames = ['Upper Leg', 'Lower Leg', 'Foot'] jointAbbrevs = ['femur', 'tibia', 'foot'] orientIDs = ['66', '43', '8'] jointMarkerNames = [hip, knee, ankle] refMarkerNames = [[thigh, knee], [shin, ankle], []] imuMarkerNames = \ [[j + ' IMU - ' + str(i) for i in range(1,4)] for j in jointNames] jointMarkerSets = lambda c: [ list(map(c.marker, jointMarkerNames)), [list(map(c.marker, r)) for r in refMarkerNames], [list(map(c.marker, i)) for i in imuMarkerNames] ] imuMarkerSets = lambda c: [[ c.marker(i[0]) for i in imuMarkerNames ], [list(map(c.marker, i[1:])) for i in imuMarkerNames]] jointRefTrajectories = [ MultiMarkerTrajectory(j, r + i, refTime=refTime) for j, r, i in zip(*(jointMarkerSets(ref3D))) ] jointTrajectories = [ MultiMarkerTrajectory(j, r + i, refVectors=m.refVectors) \ for j, r, i, m in \ zip(*(jointMarkerSets(capture3D) + [jointRefTrajectories]))] imuRefTrajectories = [ MultiMarkerTrajectory(p, r, refTime=refTime) for p, r in zip(*(imuMarkerSets(ref3D))) ] imuVecTrajectories = [ MultiMarkerTrajectory(p, r, refVectors=m.refVectors) for p, r, m in zip(*(imuMarkerSets(capture3D) + [imuRefTrajectories])) ] imuRefMarkers = [ref6D.marker(j + ' IMU') for j in jointNames] imuOffsets = [ i.position(refTime) - j.position(refTime) for i, j in zip(imuRefTrajectories, jointRefTrajectories) ] imuRotations = [ t.rotation(refTime).conjugate * m.rotation(refTime) for t, m in zip(imuRefTrajectories, imuRefMarkers) ] imuTrajectories = [ OffsetTrajectory(v, o, r) for v, o, r in zip(imuVecTrajectories, imuOffsets, imuRotations) ] imuData = [captureSD.device(i) for i in orientIDs] joints = [] for i in range(len(jointNames)): name = jointNames[i] traj = jointTrajectories[i] if i == 0: model = SampledBodyModel(name) model.positionKeyFrames = traj.posMarker.positionKeyFrames joint = model else: parent = joints[-1] refTraj = jointRefTrajectories[i] parentRefTraj = jointRefTrajectories[i - 1] pos = refTraj.position(refTime) parentPos = parentRefTraj.position(refTime) joint = SampledJoint(joints[-1], name, offset=(pos - parentPos)) joint.rotationKeyFrames = traj.rotationKeyFrames joints.append(joint) model = SplinedBodyModel(model) joints = model.joints imuJointTrajectories = [ OffsetTrajectory(j, o, r) for j, o, r in zip(joints, imuOffsets, imuRotations) ] positionSets = [] valueSets = [] for magbase in magbases: orient = SensorDataCapture.load(magbase + '.sdc') optical = loadQualisysTSVFile(magbase + '_6D.tsv') for marker in optical.markers: device = orient.device(maglookup[marker.id]) magData = device.sensorData('magnetometer').values positionSets.append(marker.positionKeyFrames.values) valueSets.append( marker.rotationKeyFrames.values.rotateVector(magData)) positions = np.hstack(positionSets) values = np.hstack(valueSets) valid = ~np.any(np.isnan(positions), axis=0) & ~np.any(np.isnan(values), axis=0) dev = values - np.median(values[:, valid], axis=1).reshape((3, 1)) step = np.shape(values[:, valid])[1] // magSamples posSamples = positions[:, valid][:, ::step] valSamples = values[:, valid][:, ::step] environment = Environment() environment.magneticField = \ NaturalNeighbourInterpolatedField(posSamples, valSamples) sim = Simulation(environment=environment) sim.time = model.startTime distortIMUs = [] dt = 1 / capture3D.sampled.frameRate for traj in imuJointTrajectories: platform = IdealIMU(sim, traj) distortIMUs.append(BasicIMUBehaviour(platform, dt)) sim.run(model.endTime) for imu in range(3): for sensorName in ['accelerometer', 'magnetometer', 'gyroscope']: sim = getattr(distortIMUs[imu].imu, sensorName).rawMeasurements true = imuData[imu].sensorData(sensorName)(sim.timestamps + model.startTime) yield assert_vectors_correlated, sim.values, true, 0.8
def loadASFFile(asfFileName, amcFileName, scaleFactor, framePeriod): """ Load motion capture data from an ASF and AMC file pair. @param asfFileName: Name of the ASF file containing the description of the rigid body model @param amcFileName: Name of the AMC file containing the motion data @param scaleFactor: Scaling factor to convert lengths to m. For data from the CMU motion capture corpus this should be 2.54/100 to convert from inches to metres. @return: A {SampledBodyModel} representing the root of the rigid body model structure. """ with open(asfFileName, 'r') as asfFile: data = asfParser.parseFile(asfFile) scale = (1.0 / data.units.get('length', 1)) * scaleFactor bones = dict((bone.name, bone) for bone in data.bones) asfModel = ASFRoot(data.root) for entry in data.hierarchy: parent = asfModel.getBone(entry.parent) for childName in entry.children: ASFBone(parent, bones[childName], scale) imusimModel = SampledBodyModel('root') for subtree in asfModel.children: for bone in subtree: if not bone.isDummy: offset = vector(0, 0, 0) ancestors = bone.ascendTree() while True: ancestor = ancestors.next().parent offset += ancestor.childoffset if not ancestor.isDummy: break SampledJoint(parent=imusimModel.getJoint(ancestor.name), name=bone.name, offset=offset) if not bone.hasChildren: PointTrajectory(parent=imusimModel.getJoint(bone.name), name=bone.name + '_end', offset=bone.childoffset) with open(amcFileName) as amcFile: motion = amcParser.parseFile(amcFile) t = 0 for frame in motion.frames: for bone in frame.bones: bonedata = asfModel.getBone(bone.name) if bone.name == 'root': data = dict((chan.lower(), v) for chan, v in zip( bonedata.channels, bone.channels)) position = convertCGtoNED( scale * vector(data['tx'], data['ty'], data['tz'])) imusimModel.positionKeyFrames.add(t, position) axes, angles = zip(*[(chan[-1], angle) for chan, angle in zip( bonedata.channels, bone.channels) if chan.lower().startswith('r')]) rotation = (bonedata.rotationOffset.conjugate * Quaternion.fromEuler(angles[::-1], axes[::-1])) joint = imusimModel.getJoint(bone.name) if joint.hasParent: parentRot = joint.parent.rotationKeyFrames.latestValue parentRotOffset = bonedata.parent.rotationOffset rotation = parentRot * parentRotOffset * rotation else: rotation = convertCGtoNED(rotation) joint.rotationKeyFrames.add(t, rotation) t += framePeriod return imusimModel