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Diffstat (limited to 'LibOVR/Src/Tracking/Tracking_SensorStateReader.cpp')
| -rw-r--r-- | LibOVR/Src/Tracking/Tracking_SensorStateReader.cpp | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/LibOVR/Src/Tracking/Tracking_SensorStateReader.cpp b/LibOVR/Src/Tracking/Tracking_SensorStateReader.cpp new file mode 100644 index 0000000..b290480 --- /dev/null +++ b/LibOVR/Src/Tracking/Tracking_SensorStateReader.cpp @@ -0,0 +1,207 @@ +/************************************************************************************ + +Filename : Tracking_SensorStateReader.cpp +Content : Separate reader component that is able to recover sensor pose +Created : June 4, 2014 +Authors : Chris Taylor + +Copyright : Copyright 2014 Oculus VR, Inc. All Rights reserved. + +Licensed under the Oculus VR Rift SDK License Version 3.1 (the "License"); +you may not use the Oculus VR Rift SDK except in compliance with the License, +which is provided at the time of installation or download, or which +otherwise accompanies this software in either electronic or hard copy form. + +You may obtain a copy of the License at + +http://www.oculusvr.com/licenses/LICENSE-3.1 + +Unless required by applicable law or agreed to in writing, the Oculus VR SDK +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. + +*************************************************************************************/ + +#include "Tracking_SensorStateReader.h" +#include "Tracking_PoseState.h" + +namespace OVR { namespace Tracking { + + +//------------------------------------------------------------------------------------- + +// This is a "perceptually tuned predictive filter", which means that it is optimized +// for improvements in the VR experience, rather than pure error. In particular, +// jitter is more perceptible at lower speeds whereas latency is more perceptible +// after a high-speed motion. Therefore, the prediction interval is dynamically +// adjusted based on speed. Significant more research is needed to further improve +// this family of filters. +static Pose<double> calcPredictedPose(const PoseState<double>& poseState, double predictionDt) +{ + Pose<double> pose = poseState.ThePose; + const double linearCoef = 1.0; + Vector3d angularVelocity = poseState.AngularVelocity; + double angularSpeed = angularVelocity.Length(); + + // This could be tuned so that linear and angular are combined with different coefficients + double speed = angularSpeed + linearCoef * poseState.LinearVelocity.Length(); + + const double slope = 0.2; // The rate at which the dynamic prediction interval varies + double candidateDt = slope * speed; // TODO: Replace with smoothstep function + + double dynamicDt = predictionDt; + + // Choose the candidate if it is shorter, to improve stability + if (candidateDt < predictionDt) + { + dynamicDt = candidateDt; + } + + if (angularSpeed > 0.001) + { + pose.Rotation = pose.Rotation * Quatd(angularVelocity, angularSpeed * dynamicDt); + } + + pose.Translation += poseState.LinearVelocity * dynamicDt; + + return pose; +} + + +//// SensorStateReader + +SensorStateReader::SensorStateReader() : + Updater(NULL), + LastLatWarnTime(0.) +{ +} + +void SensorStateReader::SetUpdater(const CombinedSharedStateUpdater* updater) +{ + Updater = updater; +} + +void SensorStateReader::RecenterPose() +{ + if (!Updater) + { + return; + } + + /* + This resets position to center in x, y, z, and resets yaw to center. + Other rotation components are not affected. + */ + + const LocklessSensorState lstate = Updater->SharedSensorState.GetState(); + + Posed worldFromCpf = lstate.WorldFromImu.ThePose * lstate.ImuFromCpf; + + double hmdYaw, hmdPitch, hmdRoll; + worldFromCpf.Rotation.GetEulerAngles<Axis_Y, Axis_X, Axis_Z>(&hmdYaw, &hmdPitch, &hmdRoll); + + Posed worldFromCentered(Quatd(Axis_Y, hmdYaw), worldFromCpf.Translation); + + CenteredFromWorld = worldFromCentered.Inverted(); +} + +bool SensorStateReader::GetSensorStateAtTime(double absoluteTime, TrackingState& ss) const +{ + if (!Updater) + { + ss.StatusFlags = 0; + return false; + } + + const LocklessSensorState lstate = Updater->SharedSensorState.GetState(); + + // Update time + ss.HeadPose.TimeInSeconds = absoluteTime; + + // Update the status flags + ss.StatusFlags = lstate.StatusFlags; + // If no hardware is connected, override the tracking flags + if (0 == (ss.StatusFlags & Status_HMDConnected)) + { + ss.StatusFlags &= ~Status_TrackingMask; + } + if (0 == (ss.StatusFlags & Status_PositionConnected)) + { + ss.StatusFlags &= ~(Status_PositionTracked | Status_CameraPoseTracked); + } + + // If tracking info is invalid, + if (0 == (ss.StatusFlags & Status_TrackingMask)) + { + return false; + } + + // Delta time from the last available data + double pdt = absoluteTime - lstate.WorldFromImu.TimeInSeconds; + static const double maxPdt = 0.1; + + // If delta went negative due to synchronization problems between processes or just a lag spike, + if (pdt < 0.) + { + pdt = 0.; + } + else if (pdt > maxPdt) + { + if (LastLatWarnTime != lstate.WorldFromImu.TimeInSeconds) + { + LastLatWarnTime = lstate.WorldFromImu.TimeInSeconds; + LogText("[SensorStateReader] Prediction interval too high: %f s, clamping at %f s\n", pdt, maxPdt); + } + pdt = maxPdt; + } + + ss.HeadPose = PoseStatef(lstate.WorldFromImu); + // Do prediction logic and ImuFromCpf transformation + ss.HeadPose.ThePose = Posef(CenteredFromWorld * calcPredictedPose(lstate.WorldFromImu, pdt) * lstate.ImuFromCpf); + + ss.CameraPose = Posef(CenteredFromWorld * lstate.WorldFromCamera); + + Posed worldFromLeveledCamera = Posed(Quatd(), lstate.WorldFromCamera.Translation); + ss.LeveledCameraPose = Posef(CenteredFromWorld * worldFromLeveledCamera); + + ss.RawSensorData = lstate.RawSensorData; + + return true; +} + +bool SensorStateReader::GetPoseAtTime(double absoluteTime, Posef& transform) const +{ + TrackingState ss; + if (!GetSensorStateAtTime(absoluteTime, ss)) + { + return false; + } + + transform = ss.HeadPose.ThePose; + + return true; +} + +uint32_t SensorStateReader::GetStatus() const +{ + if (!Updater) + { + return 0; + } + + const LocklessSensorState lstate = Updater->SharedSensorState.GetState(); + + // If invalid, + if (0 == (lstate.StatusFlags & Status_TrackingMask)) + { + // Return 0 indicating no orientation nor position tracking + return 0; + } + + return lstate.StatusFlags; +} + + +}} // namespace OVR::Tracking |