The Artec Spider and Spider 2 may at times acquire an abundance of noise, and this article will give some tips on how to mitigate it.
Firstly, noise is generated because we are increasing the gain (brightness) on the geometry cameras. We increase the gain on the geometry cameras to see as much of the surface of the item we are scanning as possible. This will allow us to get as deep as possible in holes.
Secondly, a poorly calibrated 3D scanner may produce more noise. So, please, warm-up your device for 15-25 minutes, and calibrate it preferably immediately before your scanning session. This will also improve and optimize the field of view as well as improving accuracy.
The noise can sometimes appear like snow within a snowglobe. And, it can be difficult to delete the noise efficiently without deleting the surface of the item we want to keep. If you change the color mode to X-Ray, the silhouette of the actual model will be more apparent, and this will help you make selections to erase.
A more automated global way to delete noise is the outlier filter. This is applied at the scan level before fusion, and can work to your advantage to produce a clean mesh without extra artifacts, however, it can also be destructive, deleting parts of your item where the data is sparse (but you still want to retain it). If the default value is not 'strong' enough, you may increase it to 4.0 3D-Noise level to see if you prefer the results.
Another option is the 'small object filter', which is part of Tools/3D Models/'Mesh Optimization'/'Artifact Healing'. Click on 'Removal Small Objects'.
This post-fusion outlier filter can work well, but if the noise is attached to the rest of the geometry, then this tool will not be able to isolate and delete the noise. Typically, at this point, I would go to the previous stage of editing the scans, and produce a new fusion without the noise.
When fusing, the 'watertight' setting for Fill Holes can produce great results, but it can also produce 'strange' looking shapes because the software will make the mesh watertight, even if it means compromising the shape and silhouette of the model. A solution could be to use a different hole-filling method than watertight, and then addressing those holes afterwards, like creating bridges to constrain the holes, and forcing them to be filled with a certain arc to match the surrounding geometry.
If you know the object you are scanning will produce noise, yet another option is to spray the object with a dulling spray or 3D scanning spray like AESUB, which will allow the data to capture more easily, and you could potentially get away with less geometry gain, which would therein reduce the noise.