The point cloud effect is good, but when filtering the points, a wave-like pattern appears, which leads to poor edge effect. What is the reason for this? How can it be resolved?

Software version: 1.6.2
Camera firmware version: 2.0.2
ETH,and working distance of 1.5m
The point cloud effect is very smooth, with minimal fluctuations.

When using point cloud filtering, the point cloud is being filtered in a wave-like pattern, resulting in poor edge effects and low edge matching accuracy.
Point Cloud Filtering Parameters

1, The purpose of point cloud filtering is mainly to filter out noisy and unnecessary points from the point cloud. From the observed situation in the figure, it seems that there are not many noisy points. Therefore, it is recommended to use the default normal angle threshold for point filtering, which is generally set to 90°.

2, The point cloud visualization in the effect diagram does not display the normal vectors of the points. To observe the differences in the normal vectors of the point cloud, you can enable the “Show Point Cloud Normals” option in the display settings. This will allow you to visualize the effect of filtering based on point normals and have a more intuitive understanding of the filtering results.

I use a 50° filtering because I need to filter out the point cloud of the product’s side surface, as shown in the figure:

Sometimes, even with a 50-degree filtering, it is still challenging to effectively filter out the point cloud of the side surface. This can be quite tricky.
Additionally, extracting edges becomes difficult. As shown in the figure, when using a 45-degree filtering:
So, it is necessary to use a filtering threshold below 50 degrees in order to remove the side edge point cloud. This kind of wave-like filtering effect is not always present, as there are times when it does not occur.

I would also like to ask why there is inconsistency in the normal vectors of the point cloud in such cases, and how to avoid it?

From the image, it appears that there is a uniform fluctuation in the density of the overall point cloud. This may be caused by the flickering of ambient light.

The ambient light, usually from overhead lamps, has a wide coverage across the entire scene. Consequently, the wave-like pattern in the point cloud caused by the flickering of ambient light typically covers the entire captured frame indiscriminately. In addition, due to the uniform distribution of ambient light, the width and amplitude of the wave are also uniform, and the direction is perpendicular to the camera’s baseline.

Configure and use the anti-flicker mode in the MECH-EYE software to address this issue.

Thank you. Indeed, the interference was caused by the lighting, and we have already changed the position of the lights, which has brought some improvement in the results.