To remove floating bits, delete every piece of geometry that is not connected to your object: either keep only the largest connected piece or run a filter that deletes isolated pieces below a size threshold. Surface noise is a separate job: filter outliers in the point cloud before it is turned into a mesh, or smooth the finished mesh lightly and locally once the floating bits are gone.
The rest of this guide shows how to do both in free desktop tools such as Blender, MeshLab and CloudCompare, which order to work in, and how to avoid deleting parts of the object you meant to keep.
What is the difference between noise and floating bits?
Floating bits are islands. They are clusters of triangles or points that hang in the air around the model and do not touch it: pieces of the table, the wall behind the object, your fingers, a reflection the software read as a surface. Artec's documentation describes these outliers as "small surfaces unconnected to the main surfaces" and warns that they can spoil the model or produce unwanted fragments.
Noise is attached to the surface. It shows up as a fuzzy, bumpy skin on areas that should be smooth, or, in a point cloud, as a haze of stray points hovering just above the real surface.
The distinction matters because the tools are different. Floating bits are a connectivity problem, so you remove them by selecting what is connected and deleting the rest. Noise is a geometry problem, so you remove it by filtering points by distance or by smoothing. If you smooth a scan that still has floating bits, you spend time smoothing debris you are about to delete.
Should you clean the point cloud or the mesh?
Clean the point cloud if you have one. Once noise is turned into triangles, stray points become small spikes and shells welded to the surface, which are harder to remove than loose points. Artec recommends removing outliers before fusion rather than after, fusion being the step that turns the captured frames into a polygonal 3D model, because it reduces the chance of noisy features attaching to the main surface.
The standard tool for this is a statistical outlier filter. In CloudCompare it lives under Tools > Clean > SOR filter: for each point it computes the average distance to its k nearest neighbours, then rejects points that lie farther than the average distance plus n standard deviations. You set two numbers, the neighbour count and the multiplier. A smaller multiplier removes more points. Artec's own outlier removal works on the same statistical principle, and its manual recommends a standard-deviation multiplier of 2 for noisier surfaces and 3 for less noisy ones. Whatever value you start with, compare the result with the original and raise the multiplier if the filter starts eating into the real surface.
If your scanning app gives you a finished mesh rather than a point cloud, go straight to mesh cleanup. The table below shows which tool fits which job.
| Tool | What it removes | Best for |
|---|---|---|
| Blender: Select Linked, then invert and delete | Everything not connected to the part you picked | Manual control over what stays |
| Blender: Delete Loose | Vertices, edges and optionally faces connected to nothing | Leftover specks after other cleanup |
| MeshLab: Remove Isolated pieces (wrt Diameter) | Connected pieces smaller than a size threshold | Many small fragments around a large object |
| MeshLab: Remove Isolated pieces (wrt Face Num.) | Connected pieces with fewer triangles than a threshold | Dense meshes with tiny debris |
| CloudCompare: SOR filter | Points far from their neighbours | Point clouds, before meshing |
| Artec Studio: Small-object filter | All objects except the largest, or those under a polygon count | Artec users, after fusion |
How do you delete floating bits in Blender?
Blender is free and imports common mesh formats such as OBJ and STL. The cleanest method is to select the object and delete everything else.
- Import the scan and keep the original file untouched, so you can start over.
- Press Tab to enter Edit Mode and deselect everything.
- Hover the mouse over the main object and press L. Select Linked selects all geometry connected directly or indirectly to the element under the cursor; Ctrl-L does the same from an existing selection.
- If your object is genuinely made of several separate parts, hover over each one and press L again to add it.
- Invert the selection (Select ‣ Invert) and delete the vertices. Every floating island goes at once.
- Select everything again, because both clean-up tools work only on the selection. Run Mesh ‣ Clean up ‣ Delete Loose, which deletes the selected vertices, edges and, optionally, faces that are not connected to anything. Then run Merge by Distance from the same menu to merge selected vertices that sit closer together than a distance you choose.
Skipping step 4 is how people lose parts. A thin handle, a strap or a cable that the scanner captured with a gap will be a separate island, and it disappears with the debris. Before deleting, orbit around the model and check that nothing you want to keep is highlighted.
How do you remove floating bits automatically in MeshLab?
When a scan has hundreds of fragments, clicking them one by one is slow. MeshLab, also free, has cleaning filters that remove them by size. The PyMeshLab filter reference documents what each one does and its defaults:
- Remove Isolated pieces (wrt Diameter) deletes every connected piece smaller than a diameter you set as a percentage; the default is 10%.
- Remove Isolated pieces (wrt Face Num.) deletes every piece made of fewer triangles than a number you set; the default is 25.
- Select small disconnected component only selects small pieces, judged against the face count of the largest piece, so you can inspect them before deleting.
Both removal filters also delete the vertices left without faces, by default. Start with the default value, look at the result, then raise the threshold step by step until the debris is gone. Stop as soon as a wanted part starts to vanish and finish that area by hand.
The selection filter is the safer choice on an unfamiliar scan. It shows you exactly what would be removed, and you press delete yourself.
What if the junk is attached to the object?
Connectivity tools only see islands. If the scanner fused the tabletop, a turntable or the floor to the base of your object, that surface is part of the main piece, and no isolated-piece filter will touch it.
Cut it off manually. In Blender, switch to a side view, turn on X-ray so the selection reaches through the model, box-select everything below the object's base and delete it. A flat base then leaves an open hole. Close it with a fill operation; our guide on how to fix holes and clean up a 3D scan walks through the options.
Do this before any automatic filter. Once the base is cut, fragments that were touching it become islands, and the filters can catch them.
How do you smooth surface noise without losing detail?
Smoothing averages each vertex with its neighbours, so it removes bumps and real detail alike. Artec's documentation separates the two uses: mesh smoothing filters low-amplitude noise over the whole model, while a smoothing brush works only on the areas with the most noise.
Prefer local smoothing. Apply it to flat or gently curved areas where the noise is obvious, and leave edges, engraved text and small features alone. Work in light passes and stop once the noise is gone, because heavy global smoothing rounds corners and thins narrow parts. If you will take measurements from the scan, measure a reference distance before and after smoothing to confirm it did not change.
Some noise is better fixed by scanning again than by smoothing. Artec's manual explains that low-amplitude surface noise normally means the area was captured in too few frames, and that areas captured at an oblique angle are noisier than areas captured head-on; one more scan of the noisy area corrects it. Fuzzy or doubled surfaces have causes of their own, covered in why 3D scans come out blurry. Spiky patches on chrome, black plastic or glass come from the surface itself, and the fix happens at capture time, as explained in how to scan shiny, black or transparent objects.
In what order should you clean a scan?
A fixed order prevents double work:
- Keep the original file and work on a copy.
- If you have a point cloud, run an outlier filter before meshing.
- Cut away supporting surfaces fused to the object.
- Remove floating islands with Select Linked and invert, or with an isolated-piece filter.
- Delete loose geometry and merge duplicate vertices.
- Smooth noise locally, only where it is needed.
- Fill holes, then check the model from every side.
- Export in the format your next step needs; see how to export a 3D scan to STL, OBJ or USDZ.
The less junk you capture, the less you have to delete. Give the object space: put it on a plain surface with nothing directly behind it, and keep your hands and anything that moves out of view. If you capture with a phone app such as MagiScan, which turns the phone into a 3D scanner and exports scans for 3D printing, AR and e-commerce, run these steps on the exported file before it goes to the printer or the product page. With a clean capture, cleanup often comes down to steps 4 and 5.
Frequently Asked Questions
Why does my 3D scan have floating bits around it?
The scanner records every surface it can see, not only the object. Artec's manual notes that scanning nearly always captures unwanted elements such as walls, the operator's hands and the surface the object stands on. Whatever does not touch the object ends up as a separate piece, while the surface it stands on can fuse to its base and has to be cut off by hand.
Will removing floating bits change my measurements?
Deleting disconnected pieces does not move any vertex of the object, so its dimensions stay the same. Smoothing and hole filling do change the surface, so measure a reference distance before and after those steps if accuracy matters.
Can I keep only the biggest piece in one step?
Yes, in some programs. Artec Studio's small-object filter has an All except largest option that erases every object except the one with the most polygons. In Blender, hovering over the object, pressing L, inverting the selection and deleting gives the same result.
Do floating bits matter for 3D printing?
Yes. A slicer treats each separate shell as something to print, so a speck hanging above the model becomes a tiny part printed in mid-air, which needs support or fails. Remove the islands before you export the file for printing, whether the scan came from a desktop scanner or a phone app like MagiScan.