How VTube-LASER Cylinder Laser Spike Filter Removes Fliers on Cylinders (Also: Flier Removal)
About Laser Stripes On Cylindrical Tube ShapesLaser stripes from the scan arms comprise a string of points in space. You can see how VTube-LASER scans the stripes for cylinder in this image.
How VTube Uses Laser Stripes On Cylindrical Tube Shapes
Laser line scanner stripes form a polyline with a maximum curve on a tube when scanning a diameter.
Because of this, VTube expects a natural arc to occur as the scan line wraps around the diameter.
If any point departs too far from this path, the spike filter automatically removes outlier vertex spikes in cylindrical laser stripes.
It Finds Outliers called "Spikes" in the Curve
An outlier is detected when the angle between three adjacent points exceeds a user-entered Spike Angle value. The default value is 15 degrees.
The two points shown in the middle of this illustration are points that VTube-LASER would remove from the scan data - because the angle exceeds 15 degrees.
Handling High-Reflectivity Surface Spikes
The other situation where the laser scanner might see spikes is when measuring a highly reflective tube. The points returned from the tube surfaces from highly reflective diameter regions may be registered as spiking away from the diameter. This filter removes any data that spikes away from the curve before it is given to the VTube-LASER math engine.
Note that this issue is especially true for older generations of scanners. Any scanner released before 2020 may be subject to many more fliers during scanning. For example, this was a problem with FARO Edge arms and older. This filter is essential for scanning if you use a FARO Edge arm of any generation.
When to Increase the Spike Filter Angle
How to Change the Cylinder Laser Spike Filter Angle
Edit the value at row 17 in the Measure Setup / Laser tab menu. This value is saved per project.