# Easy3DMatch - 3D Alignment and Comparison **Easy3DMatch** allows you to: * Align a scanned object with another scan or with a reference mesh. * The **Easy3DMatch** tool features alignment functions to find the exact pose (position and orientation) of acquired 3D objects using a reference model. * You can specify this model as a reference point cloud or as a 3D mesh from CAD software (using the `stl` file format). ![CAD model.](assets/images/easy3d/easy3dmatch/purpose_1.webp)![Sample point cloud.](assets/images/easy3d/easy3dmatch/purpose_2.webp)![Model and sample aligned.](assets/images/easy3d/easy3dmatch/purpose_3.webp) ### C++ ```cpp #include ``` ```cpp using namespace eVision; // load the reference mesh and define the pose Easy3D::E3DAligner aligner; Easy3D::EMesh cad; cad.Load("..."); float azimuthReference = 0.f, elevationReference = 90.f; aligner.SetReference(cad, azimuthReference, elevationReference); // load the sample Easy3D::EPointCloud sample; sample.Load("..."); float azimuthSample = 0.f, elevationSample = -90.f; // perform alignment Easy3D::E3DAlignment alignment = aligner.Align(sample, azimuthSample, elevationSample); ``` ### C# ```cs using eVision.Easy3D; ``` ```cs // load the reference mesh and define the pose E3DAligner aligner = new E3DAligner(); EMesh cad = new EMesh(); cad.Load("..."); float azimuthReference = 0.0f, elevationReference = 90.0f; aligner.SetReference(cad, azimuthReference, elevationReference); // load the sample EPointCloud sample = new EPointCloud(); sample.Load("..."); float azimuthSample = 0.0f, elevationSample = -90.0f; // perform alignment E3DAlignment alignment = aligner.Align(sample, azimuthSample, elevationSample); ``` ### Python ```py from eVision import Easy3D # load the reference mesh and define the pose aligner = Easy3D.E3DAligner() cad = Easy3D.EMesh() cad.Load("...") aligner.SetReference(cad, azimuth=0., elevation=90.) # load the sample sample = Easy3D.EPointCloud() sample.Load("...") # perform alignment alignment = aligner.Align(sample, azimuth=0., elevation=-90.) ``` * Compare an aligned scan with a reference model or mesh: 1. Compute the local distances between 3D scans and a golden sample or a reference mesh. 2. Detect anomalies such as misplaced features, geometric distortions, gaps and bumps. ![Reference.](assets/images/easy3d/easy3dmatch/purpose_4.webp)![Sample.](assets/images/easy3d/easy3dmatch/purpose_5.webp)![](assets/images/easy3d/easy3dmatch/purpose_6.webp) ### C++ ```cpp #include ``` ```cpp using namespace eVision; using namespace eVision::Easy3D; // load the reference golden scan and set reference E3DMatcher matcher; EPointCloud reference; float azimuthReference = 0.f, elevationReference = 90.f; reference.Load("..."); matcher.SetReference(reference, azimuthReference, elevationReference); // Set thresholds float distanceThresh = .2f, areaThresh = 1.f; matcher.SetAnomalyThresholds(EAnomalyThresholds(distanceThresh, areaThresh)); // Prepare data structures (optional) matcher.PrepareReference(); // load the sample and perform comparison EPointCloud sample; float azimuthSample = 0.f, elevationSample = -90.f; sample.Load("..."); E3DMatch match = matcher.Match(sample, azimuthSample, elevationSample); std::vector anomalies = match.GetAnomalies(); //TODO: if (anomalies.size() != 0u): an anomaly was detected: inspect the sample manually? throw it away? // get cloud to inspect it manually EPointCloud visualisationCloud; matcher.GetComparisonPointCloud(visualisationCloud); ``` ### C# ```cs using eVision.Easy3D; ``` ```cs // load the reference golden scan and set reference E3DMatcher matcher = new E3DMatcher(); EPointCloud reference = new EPointCloud(); float azimuthReference = 0.0f, elevationReference = 90.0f; reference.Load("..."); matcher.SetReference(reference, azimuthReference, elevationReference); // Set thresholds float distanceThresh = 0.2f, areaThresh = 1.0f; matcher.AnomalyThresholds = new EAnomalyThresholds(distanceThresh, areaThresh); // Prepare data structures (optional) matcher.PrepareReference(); // load the sample and perform comparison EPointCloud sample = new EPointCloud(); float azimuthSample = 0.0f, elevationSample = -90.0f; sample.Load("..."); E3DMatch match = matcher.Match(sample, azimuthSample, elevationSample); E3DAnomaly[] anomalies = match.Anomalies; //TODO: if (anomalies.Length != 0): an anomaly was detected: inspect the sample manually? throw it away? // get cloud to inspect it manually EPointCloud visualisationCloud = new EPointCloud(); matcher.GetComparisonPointCloud(visualisationCloud); ``` ### Python ```py from eVision import Easy3D # load the reference golden scan and set reference matcher = Easy3D.E3DMatcher() reference = Easy3D.EPointCloud() reference.Load("...") matcher.SetReference(reference, azimuth=0., elevation=90.) # Set thresholds matcher.AnomalyThresholds = Easy3D.EAnomalyThresholds(distanceThreshold=0.2, areaThreshold=1.) # Prepare data structures (optional) matcher.PrepareReference() # load the sample and perform comparison sample = Easy3D.EPointCloud() sample.Load("...") match = matcher.Match(sample, azimuth=0., elevation=-90.) anomalies = match.Anomalies #TODO: if len(anomalies) != 0: an anomaly was detected: inspect the sample manually? throw it away? # get cloud to inspect it manually visualisation_cloud = Easy3D.EPointCloud() matcher.GetComparisonPointCloud(visualisation_cloud) ``` The basic workflow for using Easy3DMatch is as follows: 1. Load a reference as: * A mesh (define its viewpoints) * A point cloud (with one viewpoint) * A ZMap 2. Load a sample, either as: * A point cloud (with one viewpoint) * A ZMap 3. Perform alignment and/or matching: * Optionally, align the sample and get its [`E3DAlignment`](../../../doxygen_cpp/classeVision_1_1Easy3D_1_1E3DAlignment.html) [.NET](../../../doxygen_cs/classeVision_1_1Easy3D_1_1E3DAlignment.html) [Python](../../../doxygen_python/classeVision_1_1Easy3D_1_1E3DAlignment.html) with respect to the reference ([`E3DAligner`](../../../doxygen_cpp/classeVision_1_1Easy3D_1_1E3DAligner.html) [.NET](../../../doxygen_cs/classeVision_1_1Easy3D_1_1E3DAligner.html) [Python](../../../doxygen_python/classeVision_1_1Easy3D_1_1E3DAligner.html)). * Optionally, compare the sample to the reference by defining ROIs as [`E3DBox`](../../../doxygen_cpp/classeVision_1_1Easy3D_1_1E3DBox.html) [.NET](../../../doxygen_cs/classeVision_1_1Easy3D_1_1E3DBox.html) [Python](../../../doxygen_python/classeVision_1_1Easy3D_1_1E3DBox.html) ([`E3DComparer`](../../../doxygen_cpp/classeVision_1_1Easy3D_1_1E3DComparer.html) [.NET](../../../doxygen_cs/classeVision_1_1Easy3D_1_1E3DComparer.html) [Python](../../../doxygen_python/classeVision_1_1Easy3D_1_1E3DComparer.html)). * Align the sample and compare it directly to the reference by defining ROIs as an [`ERegion`](../../../doxygen_cpp/classeVision_1_1ERegion.html) [.NET](../../../doxygen_cs/classeVision_1_1ERegion.html) [Python](../../../doxygen_python/classeVision_1_1ERegion.html) ([`E3DMatcher`](../../../doxygen_cpp/classeVision_1_1Easy3D_1_1E3DMatcher.html) [.NET](../../../doxygen_cs/classeVision_1_1Easy3D_1_1E3DMatcher.html) [Python](../../../doxygen_python/classeVision_1_1Easy3D_1_1E3DMatcher.html)). 4. Use the transformation from sample to model to locate the sample and/or process the detected [`E3DAnomaly`](../../../doxygen_cpp/classeVision_1_1Easy3D_1_1E3DAnomaly.html) [.NET](../../../doxygen_cs/classeVision_1_1Easy3D_1_1E3DAnomaly.html) [Python](../../../doxygen_python/classeVision_1_1Easy3D_1_1E3DAnomaly.html). ## Contents How to perform 3D alignment, comparison and matching. How to fuse multiple sensors for 3D matching. ## Quick Links List of all Classes, Structs and Enumerations of the **Easy3DMatch** library. Code snippets for the **Easy3DMatch** library. #### SEE ALSO The **3D point cloud merger** sample in **eVision Studio** illustrates how to use the **Easy3DMatch** library.