Lidar3D.cpp

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/*+-------------------------------------------------------------------------+
  |                       MultiVehicle simulator (libmvsim)                 |
  |                                                                         |
  | Copyright (C) 2014-2023  Jose Luis Blanco Claraco                       |
  | Copyright (C) 2017  Borys Tymchenko (Odessa Polytechnic University)     |
  | Distributed under 3-clause BSD License                                  |
  |   See COPYING                                                           |
  +-------------------------------------------------------------------------+ */

#include <mrpt/core/lock_helper.h>
#include <mrpt/maps/CSimplePointsMap.h>
#include <mrpt/opengl/COpenGLScene.h>
#include <mrpt/opengl/stock_objects.h>
#include <mrpt/random.h>
#include <mrpt/version.h>
#include <mvsim/Sensors/Lidar3D.h>
#include <mvsim/VehicleBase.h>
#include <mvsim/World.h>
#include <mvsim/WorldElements/OccupancyGridMap.h>

#if MRPT_VERSION >= 0x270
#include <mrpt/opengl/OpenGLDepth2LinearLUTs.h>
#endif

#include "xml_utils.h"

using namespace mvsim;
using namespace rapidxml;

MRPT_TODO("Also store obs as CObservationRotatingScan?")

Lidar3D::Lidar3D(Simulable& parent, const rapidxml::xml_node<char>* root)
        : SensorBase(parent)
{
        Lidar3D::loadConfigFrom(root);
}

Lidar3D::~Lidar3D() {}

void Lidar3D::loadConfigFrom(const rapidxml::xml_node<char>* root)
{
        gui_uptodate_ = false;

        SensorBase::loadConfigFrom(root);
        SensorBase::make_sure_we_have_a_name("laser");

        // Other scalar params:
        TParameterDefinitions params;
        params["pose_3d"] = TParamEntry("%pose3d", &sensorPoseOnVeh_);
        params["range_std_noise"] = TParamEntry("%lf", &rangeStdNoise_);
        params["sensor_period"] = TParamEntry("%lf", &sensor_period_);
        params["min_range"] = TParamEntry("%f", &minRange_);
        params["max_range"] = TParamEntry("%f", &maxRange_);
        params["viz_pointSize"] = TParamEntry("%f", &viz_pointSize_);
        params["ignore_parent_body"] = TParamEntry("%bool", &ignore_parent_body_);

        params["vert_fov_degrees"] = TParamEntry("%lf_deg", &vertical_fov_);
        params["vert_nrays"] = TParamEntry("%i", &vertNumRays_);
        params["horz_nrays"] = TParamEntry("%i", &horzNumRays_);

        params["fbo_nrows"] = TParamEntry("%i", &fbo_nrows_);

        // Parse XML params:
        parse_xmlnode_children_as_param(*root, params, varValues_);
}

void Lidar3D::internalGuiUpdate(
        const mrpt::optional_ref<mrpt::opengl::COpenGLScene>& viz,
        [[maybe_unused]] const mrpt::optional_ref<mrpt::opengl::COpenGLScene>&
                physical,
        [[maybe_unused]] bool childrenOnly)
{
        mrpt::opengl::CSetOfObjects::Ptr glVizSensors;
        if (viz)
        {
                glVizSensors = std::dynamic_pointer_cast<mrpt::opengl::CSetOfObjects>(
                        viz->get().getByName("group_sensors_viz"));
                if (!glVizSensors) return;      // may happen during shutdown
        }

        // 1st time?
        if (!glPoints_ && glVizSensors)
        {
                glPoints_ = mrpt::opengl::CPointCloudColoured::Create();
                glPoints_->setPointSize(viz_pointSize_);
                glPoints_->setLocalRepresentativePoint({0, 0, 0.10f});

                glVizSensors->insert(glPoints_);
        }
        if (!gl_sensor_origin_ && viz)
        {
                gl_sensor_origin_ = mrpt::opengl::CSetOfObjects::Create();
#if MRPT_VERSION >= 0x270
                gl_sensor_origin_->castShadows(false);
#endif
                gl_sensor_origin_corner_ =
                        mrpt::opengl::stock_objects::CornerXYZSimple(0.15f);

                gl_sensor_origin_->insert(gl_sensor_origin_corner_);

                gl_sensor_origin_->setVisibility(false);
                viz->get().insert(gl_sensor_origin_);
                SensorBase::RegisterSensorOriginViz(gl_sensor_origin_);
        }
        if (!gl_sensor_fov_ && viz)
        {
                gl_sensor_fov_ = mrpt::opengl::CSetOfObjects::Create();

                MRPT_TODO("render 3D lidar FOV");
#if 0
                auto fovScan = mrpt::opengl::CPlanarLaserScan::Create();
                gl_sensor_fov_->insert(fovScan);
#endif
                gl_sensor_fov_->setVisibility(false);
                viz->get().insert(gl_sensor_fov_);
                SensorBase::RegisterSensorFOVViz(gl_sensor_fov_);
        }

        if (!gui_uptodate_ && glVizSensors->isVisible())
        {
                {
                        std::lock_guard<std::mutex> csl(last_scan_cs_);
                        if (last_scan2gui_ && last_scan2gui_->pointcloud)
                        {
                                glPoints_->loadFromPointsMap(last_scan2gui_->pointcloud.get());
                                gl_sensor_origin_corner_->setPose(last_scan2gui_->sensorPose);

                                last_scan2gui_.reset();
                        }
                }
                gui_uptodate_ = true;
        }

        const mrpt::poses::CPose3D p = vehicle_.getCPose3D() + sensorPoseOnVeh_;

        if (glPoints_) glPoints_->setPose(p);
        if (gl_sensor_fov_) gl_sensor_fov_->setPose(p);
        if (gl_sensor_origin_) gl_sensor_origin_->setPose(p);
        if (glCustomVisual_) glCustomVisual_->setPose(p);
}

void Lidar3D::simul_pre_timestep([[maybe_unused]] const TSimulContext& context)
{
}

// Simulate sensor AFTER timestep, with the updated vehicle dynamical state:
void Lidar3D::simul_post_timestep(const TSimulContext& context)
{
        Simulable::simul_post_timestep(context);

        if (SensorBase::should_simulate_sensor(context))
        {
                auto lckHasTo = mrpt::lockHelper(has_to_render_mtx_);

                // Will run upon next async call of simulateOn3DScene()
                if (has_to_render_.has_value())
                {
                        world_->logFmt(
                                mrpt::system::LVL_WARN,
                                "Time for a new sample came without still simulating the "
                                "last one (!) for simul_time=%.03f s.",
                                has_to_render_->simul_time);
                }

                has_to_render_ = context;
                world_->mark_as_pending_running_sensors_on_3D_scene();
        }
}

void Lidar3D::freeOpenGLResources()
{
        // Free fbo:
        fbo_renderer_depth_.reset();
}

void Lidar3D::simulateOn3DScene(mrpt::opengl::COpenGLScene& world3DScene)
{
        using namespace mrpt;  // _deg

        {
                auto lckHasTo = mrpt::lockHelper(has_to_render_mtx_);
                if (!has_to_render_.has_value()) return;
        }

        auto tleWhole = mrpt::system::CTimeLoggerEntry(
                world_->getTimeLogger(), "sensor.3Dlidar");

        auto tle1 = mrpt::system::CTimeLoggerEntry(
                world_->getTimeLogger(), "sensor.3Dlidar.acqGuiMtx");

        tle1.stop();

        // The sensor body must be made of transparent material! :-)
        if (glCustomVisual_) glCustomVisual_->setVisibility(false);

        // Create empty observation:
        auto curObs = mrpt::obs::CObservationPointCloud::Create();
        curObs->sensorPose = sensorPoseOnVeh_;
        curObs->timestamp = world_->get_simul_timestamp();
        curObs->sensorLabel = name_;

        auto curPtsPtr = mrpt::maps::CSimplePointsMap::Create();
        auto& curPts = *curPtsPtr;
        curObs->pointcloud = curPtsPtr;

        // Create FBO on first use, now that we are here at the GUI / OpenGL thread.
        constexpr double camModel_hFOV = 120.01_deg;
        const int FBO_NROWS = fbo_nrows_;
        // This FBO is for camModel_hFOV only:
        const int FBO_NCOLS = horzNumRays_;

        // worst vFOV case: at each sub-scan render corner:
        const double camModel_vFOV =
                std::min(179.0_deg, 2.05 * atan2(1.0, 1.0 / cos(camModel_hFOV * 0.5)));

        mrpt::img::TCamera camModel;
        camModel.ncols = FBO_NCOLS;
        camModel.nrows = FBO_NROWS;
        camModel.cx(camModel.ncols / 2.0);
        camModel.cy(camModel.nrows / 2.0);
        camModel.fx(camModel.cx() / tan(camModel_hFOV * 0.5));  // tan(FOV/2)=cx/fx
        camModel.fy(camModel.cy() / tan(camModel_vFOV * 0.5));

        if (!fbo_renderer_depth_)
        {
                mrpt::opengl::CFBORender::Parameters p;
                p.width = FBO_NCOLS;
                p.height = FBO_NROWS;
                p.create_EGL_context = world()->sensor_has_to_create_egl_context();

#if MRPT_VERSION >= 0x270
                // Do the log->linear conversion ourselves for this sensor, since only a
                // few depth points are actually used.
                p.raw_depth = true;
#endif

                fbo_renderer_depth_ = std::make_shared<mrpt::opengl::CFBORender>(p);
        }

        const size_t nCols = horzNumRays_;
        const size_t nRows = vertNumRays_;

        mrpt::math::CMatrixDouble rangeImage(nRows, nCols);
        rangeImage.setZero();  // 0=invalid (no lidar return)

        auto viewport = world3DScene.getViewport();

        // Disable rendering of shadows for this sensor:
#if MRPT_VERSION >= 0x270
        const bool wasShadowEnabled = viewport->isShadowCastingEnabled();
        viewport->enableShadowCasting(false);
#endif

        auto& cam = fbo_renderer_depth_->getCamera(world3DScene);

        const auto fixedAxisConventionRot =
                mrpt::poses::CPose3D(0, 0, 0, -90.0_deg, 0.0_deg, -90.0_deg);

        const auto vehiclePose = mrpt::poses::CPose3D(vehicle_.getPose());

        // ----------------------------------------------------------
        // Decompose the horizontal lidar FOV into "n" depth images,
        // of camModel_hFOV each.
        // ----------------------------------------------------------
        ASSERT_GT_(horzNumRays_, 1);
        ASSERT_GT_(vertNumRays_, 1);

        constexpr bool scanIsCW = false;
        constexpr double aperture = 2 * M_PI;

        const double firstAngle = -aperture * 0.5;

        const unsigned int numRenders =
                std::ceil((aperture / camModel_hFOV) - 1e-3);
        const auto numHorzRaysPerRender = mrpt::round(
                horzNumRays_ * std::min<double>(1.0, (camModel_hFOV / aperture)));

        ASSERT_(numHorzRaysPerRender > 0);

        // Precomputed LUT of bearings to pixel coordinates:
        //                         cx - u
        //  tan(horzBearing) = --------------
        //                          fx
        //
        //                             cy - v
        //  tan(vertBearing) = -------------------------
        //                      fy / cos(horzBearing)
        //
        if (lut_.empty())
        {
                lut_.resize(numHorzRaysPerRender);

                for (int i = 0; i < numHorzRaysPerRender; i++)
                {
                        lut_[i].column.resize(nRows);

                        const double horzAng =
                                (scanIsCW ? -1 : 1) *
                                (camModel_hFOV * 0.5 -
                                 i * camModel_hFOV / (numHorzRaysPerRender - 1));

                        const double cosHorzAng = std::cos(horzAng);

                        const auto pixel_u = mrpt::saturate_val<int>(
                                mrpt::round(camModel.cx() - camModel.fx() * std::tan(horzAng)),
                                0, camModel.ncols - 1);

                        for (size_t j = 0; j < nRows; j++)
                        {
                                auto& entry = lut_[i].column[j];

                                const auto vertAng =
                                        -vertical_fov_ * 0.5 + j * vertical_fov_ / (nRows - 1);

                                const double cosVertAng = std::cos(vertAng);

                                const auto pixel_v = mrpt::round(
                                        camModel.cy() -
                                        camModel.fy() * std::tan(vertAng) / cosHorzAng);

                                // out of the simulated camera (should not happen?)
                                if (pixel_v < 0 || pixel_v >= static_cast<int>(camModel.nrows))
                                        continue;

                                entry.u = pixel_u;
                                entry.v = pixel_v;
                                entry.depth2range = 1.0f / (cosHorzAng * cosVertAng);
                        }
                }
        }
        else
        {
                // check:
                ASSERT_EQUAL_(lut_.size(), numHorzRaysPerRender);
                ASSERT_EQUAL_(lut_.at(0).column.size(), nRows);
        }

        // ----------------------------------------------------------
        // "DEPTH camera" to generate lidar readings:
        // ----------------------------------------------------------
        cam.set6DOFMode(true);
        cam.setProjectiveFromPinhole(camModel);

        viewport->setViewportClipDistances(minRange_, maxRange_);
        mrpt::math::CMatrixFloat depthImage;

        // make owner's own body invisible?
        auto visVeh = dynamic_cast<VisualObject*>(&vehicle_);
        auto veh = dynamic_cast<VehicleBase*>(&vehicle_);
        bool formerVisVehState = true;
        if (ignore_parent_body_)
        {
                if (visVeh)
                {
                        formerVisVehState = visVeh->customVisualVisible();
                        visVeh->customVisualVisible(false);
                }
                if (veh) veh->chassisAndWheelsVisible(false);
        }

#if MRPT_VERSION >= 0x270
        // Do the log->linear conversion ourselves for this sensor,
        // since only a few depth points are actually used:
        constexpr int DEPTH_LOG2LIN_BITS = 18;
        using depth_log2lin_t =
                mrpt::opengl::OpenGLDepth2LinearLUTs<DEPTH_LOG2LIN_BITS>;
        auto& depth_log2lin = depth_log2lin_t::Instance();
        const auto& depth_log2lin_lut =
                depth_log2lin.lut_from_zn_zf(minRange_, maxRange_);

#endif

        for (size_t renderIdx = 0; renderIdx < numRenders; renderIdx++)
        {
                const double thisRenderMidAngle =
                        firstAngle + (camModel_hFOV / 2.0 + camModel_hFOV * renderIdx) *
                                                         (scanIsCW ? 1 : -1);

                const auto thisDepthSensorPoseWrtSensor =
                        mrpt::poses::CPose3D::FromYawPitchRoll(
                                thisRenderMidAngle, 0.0, 0.0) +
                        fixedAxisConventionRot;

                const auto thisDepthSensorPoseOnVeh =
                        curObs->sensorPose + thisDepthSensorPoseWrtSensor;

                const auto thisDepthSensorPose = vehiclePose + thisDepthSensorPoseOnVeh;

                // Camera pose: vehicle + relativePoseOnVehicle:
                // Note: relativePoseOnVehicle should be (y,p,r)=(90deg,0,90deg)
                // to make the camera to look forward:
                cam.setPose(thisDepthSensorPose);

                auto tleRender = mrpt::system::CTimeLoggerEntry(
                        world_->getTimeLogger(), "sensor.3Dlidar.renderSubScan");

                fbo_renderer_depth_->render_depth(world3DScene, depthImage);

                tleRender.stop();

                // Add random noise:
                // Each thread must create its own rng:
                thread_local mrpt::random::CRandomGenerator rng;
                thread_local std::vector<float> noiseSeq;
                thread_local size_t noiseIdx = 0;
                constexpr size_t noiseLen = 7823;  // prime
                if (rangeStdNoise_ > 0)
                {
                        if (noiseSeq.empty())
                        {
                                noiseSeq.reserve(noiseLen);
                                for (size_t i = 0; i < noiseLen; i++)
                                        noiseSeq.push_back(rng.drawGaussian1D(0.0, rangeStdNoise_));
                        }
                }

                auto tleStore = mrpt::system::CTimeLoggerEntry(
                        world_->getTimeLogger(), "sensor.3Dlidar.storeObs");

                // Convert depth into range and store into polar range images:
                for (int i = 0; i < numHorzRaysPerRender; i++)
                {
                        const int iAbs = i + numHorzRaysPerRender * renderIdx;
                        if (iAbs >= rangeImage.cols())
                                continue;  // we don't need this image part

                        for (unsigned int j = 0; j < nRows; j++)
                        {
                                // LUT entry:
                                const auto& e = lut_.at(i).column.at(j);
                                const auto u = e.u;
                                const auto v = e.v;

                                ASSERTDEB_LT_(u, depthImage.cols());
                                ASSERTDEB_LT_(v, depthImage.rows());

                                // Depth:
                                float d = depthImage(v, u);

                                // Linearize:
#if MRPT_VERSION >= 0x270
                                // Do the log->linear conversion ourselves for this sensor,
                                // since only a few depth points are actually used:

                                // map d in [-1.0f,+1.0f] ==> real depth values:
                                d = depth_log2lin_lut
                                        [(d + 1.0f) * (depth_log2lin_t::NUM_ENTRIES - 1) / 2];
#else
                                // "d" is already linear depth
#endif
                                // Add noise:
                                if (d != 0)      // invalid range
                                {
                                        const float dNoisy = d + noiseSeq[noiseIdx++];
                                        if (noiseIdx >= noiseLen) noiseIdx = 0;

                                        if (dNoisy < 0 || dNoisy > maxRange_) continue;

                                        d = dNoisy;
                                }

                                // un-project: depth -> range:
                                const float range = d * e.depth2range;

                                if (range <= 0 || range >= maxRange_) continue;  // invalid

                                ASSERTDEB_LT_(j, rangeImage.rows());
                                ASSERTDEB_LT_(iAbs, rangeImage.cols());

                                rangeImage(j, iAbs) = range;

                                // add points:
                                const mrpt::math::TPoint3D pt_wrt_cam = {
                                        d * (u - camModel.cx()) / camModel.fx(),
                                        d * (v - camModel.cy()) / camModel.fy(), d};
                                curPts.insertPoint(
                                        thisDepthSensorPoseWrtSensor.composePoint(pt_wrt_cam));
                        }
                }
                tleStore.stop();
        }

        if (ignore_parent_body_)
        {
                if (visVeh) visVeh->customVisualVisible(formerVisVehState);
                if (veh) veh->chassisAndWheelsVisible(formerVisVehState);
        }

#if MRPT_VERSION >= 0x270
        viewport->enableShadowCasting(wasShadowEnabled);
#endif

        // Store generated obs:
        {
                auto tle3 = mrpt::system::CTimeLoggerEntry(
                        world_->getTimeLogger(), "sensor.3Dlidar.acqObsMtx");

                std::lock_guard<std::mutex> csl(last_scan_cs_);
                last_scan_ = std::move(curObs);
                last_scan2gui_ = last_scan_;
        }

        {
                auto lckHasTo = mrpt::lockHelper(has_to_render_mtx_);

                auto tlePub = mrpt::system::CTimeLoggerEntry(
                        world_->getTimeLogger(), "sensor.3Dlidar.report");

                SensorBase::reportNewObservation(last_scan_, *has_to_render_);

                tlePub.stop();

                if (glCustomVisual_) glCustomVisual_->setVisibility(true);

                gui_uptodate_ = false;

                has_to_render_.reset();
        }
}