Import STEP File to Generate Point Cloud Model and Configure Trajectory
In this workflow, you can import a STEP file to quickly generate a point cloud model and create a target object.
Under the Import STEP file workflow in target object editor, click Select, then set the target object name and STEP file path to enter the configuration process. The overall process is shown below.
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An oversized STEP file or a model with complex features may take a long time to import. It is recommended to remove irrelevant features in CAD software in advance and keep the file size under 100 MB. |
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Configure STL file: The imported STEP file is converted to an STL file. Configure the STL file, including unit and point cloud generation mode, to generate a point cloud model.
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Edit model: Edit the generated point cloud model, including calibrating the object center point and configuring the point cloud model, for better subsequent 3D matching.
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Set trajectory: Create and adjust trajectories on the edited point cloud model.
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Set collision model (optional): Generate a collision model for collision detection during trajectory planning.
The following sections describe the configuration process in detail.
Configure STL File
The imported STEP file is converted to an STL file. You must first configure the STL file to generate the point cloud model.
Select STEP File (Optional)
If you selected the wrong STEP file, or if abnormal STL model normals are found after import, click Select file to re-import the STEP file.
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Refer to STL Model Correction to learn how to determine whether STL model normals are correct and how to correct STL models. |
Set Unit
To ensure the generated point cloud model matches actual target object dimensions, set the STL model unit according to actual conditions. You can choose millimeters (mm) or meters (m).
Select Edge Point Cloud Acquisition Method
The tool provides two edge point cloud acquisition methods. Choose Auto-generate point cloud or Pick edge point cloud based on actual requirements.
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Auto-generate point cloud
After this option is selected, the tool automatically generates surface point cloud and all edge point clouds. This method is efficient, but it may generate edge point clouds that contribute little to subsequent matching, which can affect matching efficiency.
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Pick edge point cloud
After this option is selected, the tool automatically generates surface point cloud, and edge point clouds are generated through manual picking. This method helps exclude meaningless or interference edges, improving matching accuracy and stability.
The procedure for manually picking edge point clouds is as follows.
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Click Start picking to enter the "Pick edge point cloud" interface.
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Left-click along object edges to pick edges.
If you need to pick multiple continuous edges automatically, enable the "Auto-chain when picking edges" feature.
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Click Save and apply to save the picking result.
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Select the Point Cloud Generation Mode
Refer to the table below to select an appropriate point cloud generation mode based on actual requirements.
| Point cloud generation mode | Description | Effect |
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Generate from entire surface |
The software generates a point cloud according to the entire surface information of the STL model.
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Generate from specified views |
The software will generate point clouds from one or more selected views of the STL model and then stitch them together.
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In some scenarios, using the point cloud generated from the entire surface for model matching can yield better results. If the matching result based on the point cloud from a specified view is unsatisfactory, it is recommended to try using the entire surface point cloud instead. |
Set Model Downsampling Method
To ensure the density and uniform distribution of the point cloud and to maintain the matching speed, the point cloud needs to be downsampled before generating a point cloud model. In general, it is recommended to select Automatic downsampling.
If the downsampling result does not meet the requirements, select Custom downsampling and set the Sampling interval based on actual conditions. The larger the Sampling interval, the sparser the downsampled point cloud; the smaller the Sampling interval, the denser the downsampled point cloud.
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For large target objects (such as air conditioner housings), it is recommended to use Custom downsampling to prevent the loss of some feature point clouds caused by automatic downsampling. |
Now the STL file configuration is complete. Click Next to edit the generated point cloud model.
Edit Point Cloud Model
After the point cloud model is generated, it should be edited for better 3D matching.
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Errors may occur during conversion from STL model to point cloud, causing the point cloud model not to align perfectly with the STL model. |
Edit Point Cloud
Remove Interference Point Cloud
If there are interference points around the point cloud model, you can remove them by editing the point cloud. For details, refer to Edit Point Cloud.
Select Feature Point Cloud
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When making the edge point cloud model
In applications, the target objects usually come in various poses, corresponding to different point clouds. Only the point cloud most representative of the edge feature of the target object should be extracted and retained in the point cloud model.
The figure below shows the edge point cloud model of the tube. The tube is symmetrical and similar to a cylinder. On the lateral area of the cylinder, only the point cloud of the edges is retained. Meanwhile, to ensure accurate positioning of the ends of the tube, the point cloud of the edges of the two ends of the tube is retained.
The table below shows the edge point clouds of the tube at different poses.
Tube poses Edge point clouds (in yellow) 
If the target object (such as a sheet metal part) is asymmetrical, the edge point clouds from all viewing angles should be retained.
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When making the surface point cloud model
The surface point cloud model is critical in verifying the pose correctness and calculating the pose confidence. Therefore, it is recommended to use the complete surface point cloud of the target object when creating the surface point cloud model to ensure the validity. The figure below shows the surface point cloud model of the tube.
Calibrate Object Center Point
After an object center point is automatically calculated, you can calibrate it based on the actual target object in use. Select a calculation method under Calibrate center point by application, and click Start calculating to calibrate the object center point.
| Method | Description | Operation | Application Scenario |
|---|---|---|---|
Re-calculate by using original center point |
The default calculation method. Calculate the object center point according to the features of the target object and the original object center point. |
Select Re-calculate by using original center point, and click the Start calculating button. |
In general, this method can be used to calculate the center point of all target objects. |
Calibrate to center of symmetry |
Calculate the object center point according to the target object’s symmetry.
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Select Calibrate to center of symmetry and click the Start calculating button. |
This method can be used to calculate the object center point when filtering matching results by target object symmetry. |
Calibrate to center of feature |
Calculate the object center point according to the selected Feature type and the set 3D ROI. |
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Target objects with obvious geometric features
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Reset to Original Point Cloud
During editing, if the current point cloud result is unsatisfactory, click the [Reset button to undo all editing operations and restore the point cloud to its initial state when entering the "Edit model" step.
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After resetting the point cloud, you need to recalculate the object center point and update the point cloud model configuration. |
Configure Point Cloud Model
To better use the point cloud model in the subsequent 3D matching and enhance matching accuracy, the tool provides the following two options for configuring the point cloud model. You can enable the Configure point cloud model feature as needed.
Calculate Poses to Filter Matching Result
Once Calculate poses to filter matching result is enabled, more matching attempts will be made based on the settings to obtain matching results with higher confidence. However, more matching attempts will lead to longer processing time.
Two methods are available: Auto-calculate unlikely poses and Configure symmetry manually. In general, Auto-calculate unlikely poses is recommended. See the following for details.
| Method | Description | Operation |
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Auto-calculate unlikely poses |
Poses that may cause false matches will be calculated automatically. During the calculation process, a set of candidate poses is automatically generated based on equivalent or ambiguous poses that may arise due to the target object’s rotational symmetry about the Z-axis. In subsequent matches, poses that successfully match these poses will be considered unqualified and filtered out. |
Note that the calculation results will not be automatically updated when the point cloud model is modified. If there are any modifications, please click "Calculate unlikely poses" again to update the results. |
Configure symmetry manually |
Calculate potentially mismatched poses based on the manually set parameters such as the Order of symmetry and Angle range. In subsequent matches, poses that successfully match these poses will be considered unqualified and filtered out. |
Select the symmetry axis by referring to Rotational Symmetry of Target Objects, and then set the Order of symmetry and Angle range. |
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After the symmetry is set manually, the symmetry setting of the target object takes effect in the Coarse Matching, Fine Matching, and Extra Fine Matching (if enabled) processes in the 3D Matching Step. |
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After enabling the features above, if you want them to take effect in subsequent matching, you must configure the corresponding parameters in subsequent matching Steps.
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Set Weight Template
During target object recognition, setting a weight template highlights key features of the target object, improving the accuracy of matching results. The weight template is typically used to distinguish target object orientation. The procedures to set a weight template are as follows.
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A weight template can only be set when the Point cloud display settings is set to Display surface point cloud only. |
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Click Edit template.
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In the visualization area, hold and press the right mouse button to select a part of the features on the target object. The selected part, i.e., the weight template, will be assigned more weight in the matching process.
By holding Shift and the right mouse button together, you can set multiple weighted areas in a single point cloud model.
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Click Apply to complete setting the weight template.
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For the configured weight template to take effect in the subsequent matching, go to the “Model Settings” parameter of the “3D Matching” Step, and select the model with properly set weight template. Then, go to “Pose Filtering” and enable Consider Weight in Result Verification. The “Consider Weight in Result Verification” parameter will appear after the “Parameter Tuning Level” is set to Expert. |
Now point cloud model editing is complete. Click Next to set trajectories for the point cloud model.
Set Trajectory
Create Trajectory
The tool provides two ways to create trajectories: Manual creation and Automatic creation.
In this workflow, Automatic creation is recommended for creating trajectories on the STL model.
Create Trajectory Manually
In the "Set trajectory" process, click Manual creation to enter the "Manual creation" interface. The detailed procedure is as follows.
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Pick trajectory points.
Hold Shift, and right-click on the target object to pick trajectory points. The tool automatically connects picked points into a trajectory.
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Adjust trajectory points.
Created trajectory points are displayed in the list on the right side of the visualization area. If trajectory points do not meet requirements, you can adjust them as follows.
Operation Description Adjust trajectory point position and orientation
Select the trajectory point, and adjust related values in "Trajectory point settings" to change its position and orientation.
Adjust trajectory point order
Drag trajectory points in the list to reorder them.
Add trajectory point
Click Create. The tool adds a new trajectory point after the last trajectory point.
Align trajectory points
Select at least three trajectory points in the list, and click Align. The Z-axis of the selected points will be perpendicular to the fitted plane, and the X-axis will point to the next trajectory point.
Interpolate trajectory points
If picked trajectory points are unevenly distributed, you can interpolate points for more uniform distribution. + Select two trajectory points, set Maximum distance, and click Interpolate. When the distance between the two points exceeds this value, the tool automatically interpolates trajectory points between them and replaces other points between the two selected points.
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Save trajectory.
After trajectory creation is complete, click Save and apply to save the trajectory.
Create Trajectory Automatically
In the "Set trajectory" process, click Automatic creation to enter the "Automatic creation" interface. The detailed procedure is as follows.
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Set picking rules.
Before picking trajectories, set the picking rules. Details are as follows.
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Orientation settings
Parameter Description Illustration Tool orientation
This parameter sets the orientation of the end tool (such as spray gun, grinding head, glue gun) when moving along the trajectory.
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When the tool orientation is Perpendicular, the tool orientation at each trajectory point aligns with the surface normal at that point, as shown on the left. For example, a glue gun is perpendicular to the object surface.
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When the tool orientation is Tangent, the tool orientation at each trajectory point aligns with the trajectory tangent direction, as shown on the right. For example, a grinding head conforms to the object surface.
Generate opposite tool orientation
This parameter reverses tool orientation. After enabling it, tool orientation is inverted when picking trajectories, that is, the Z-axis direction of trajectory points is flipped. This feature changes only tool orientation, not trajectory point positions.
Generate opposite trajectory direction
This parameter reverses trajectory direction. After enabling it, trajectory direction is inverted when picking trajectories, that is, the X-axis direction of trajectory points is flipped. This feature changes only trajectory direction, not trajectory point positions.
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Merge settings
Parameter Description Illustration Auto-chain when picking trajectories
After enabling this feature, in one picking operation, you can continuously pick multiple adjacent trajectories, and the tool automatically stitches them into one complete continuous trajectory. This reduces repetitive operations and improves picking efficiency.
Auto-merge after picking trajectory
After enabling this feature, when picking of the current trajectory is completed, the tool attempts to merge the current trajectory with the previous one automatically. Automatic merge happens only when trajectory directions are consistent; if directions are inconsistent, automatic merge is not performed.
Consider normal orientation when merging trajectories
This parameter is a judgment condition for trajectory merge and must be used together with "Auto-merge after picking trajectory." In addition to consistent trajectory direction, tool orientation of trajectories must also be consistent for merging.
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Pick trajectories.
Left-click on the target object to pick trajectories.
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Adjust trajectory points.
Picked trajectories are shown under "Picking result." If needed, you can simplify trajectories by adjusting the following parameters. This reduces the number of trajectory points and simplifies shape while preserving overall trajectory geometry as much as possible. It is suitable for scenarios that require lower trajectory complexity, such as reducing subsequent processing time and improving robot motion efficiency.
Parameter Description Illustration Maximum deviation
Maximum allowed deviation (H) when simplifying trajectories. The larger the deviation, the fewer points remain, but trajectory shape may be distorted.
Mandatory retention spacing
If the distance (Dis) between two points in the original trajectory is greater than this value, both points are retained.
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Save trajectory.
After trajectory creation is complete, click Save and apply to save the trajectory.
Adjust Trajectory
After trajectories are created, you can adjust them.
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Adjust trajectory line
After creating a trajectory, if you need to offset the trajectory by a certain distance along the Z-axis to better meet practical operation requirements, select a trajectory line in the trajectory list and set Z-axis offset distance to offset that trajectory line along the Z-axis.
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Adjust trajectory points individually
Select a trajectory point in the trajectory list, and then adjust related values in the parameter settings area to change its position and orientation.
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For more trajectory adjustment operations, refer to Adjust Trajectory. |
Preview End Tool
After trajectories are created, you can preview the positional relationship between the end tool and trajectories as follows.
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Ensure the Mech-Viz project is in the current solution.
To ensure target object editor can obtain end tool information from Mech-Viz, refer to Export Project to Solution and move the Mech-Viz project to the current solution.
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Add an end tool.
In Mech-Viz, add an end tool and set TCP.
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Preview and enable tool.
After an end tool is added, tool information is automatically updated to the tool list in target object editor. According to actual needs, select a tool in the tool list to preview the positional relationship between trajectory and tool during actual trajectory operation in the visualization area (as shown below), or check the end tool for actual trajectory operation.
If you modified the tool in Mech-Viz, save changes in Mech-Viz to update the tool list in target object editor. In addition, enabling the corresponding end tool for the trajectory in target object editor is required for successful simulation in Mech-Viz. 
Set Collision Model (Optional)
The collision model is a 3D virtual object used in collision detection for path planning. You can configure the following settings on the collision model according to the actual situation.
Set Collision Model
The tool automatically recommends the collision model generating mode based on the current configuration workflow. The recommended mode for this case is Use STL model to generate point cloud cube. This tool will generate the point cloud cube based on the imported STL model and conduct collision detection. The collision model generated in this method features high accuracy, while the collision detection speed is lower.
You can use the "Display collision model" feature to preview the generated collision model.
Configure Symmetry of Held Target Object
Rotational symmetry is the property of the target object that allows it to coincide with itself after rotating a certain angle around its axis of symmetry. When the “Waypoint type” is “Target object pose,” configuring the rotational symmetry can prevent the robot’s tool from unnecessary rotations while handling the target object. This increases the success rate of path planning and reduces the time required for path planning, allowing the robot to move more smoothly and swiftly.
Select the symmetry axis by referring to Rotational Symmetry of Target Objects, and then set the Order of symmetry and Angle range.
Now collision model setup is complete. Click Save to save the target object to Solution folder\resource\workobject_library, and then use it in subsequent 3D matching Steps.