CloudCompare forum

I have two dental stl file which have seems have set the correct units when i opened them in freecad:


The units have set but based of this post it must not be set to specific unit :

> STL files are unit-less, so they don't contain the actual units. Most
> people use mm, as that is what all of the 3D printing slicers seem to
> expect. When you import the file, you can set the units to import in,
> and then the scaling should be correct.

When i changed the unit in freecad to meter also be using the distance tools i get same as before ( when it was on its default as mm!) like this:


That process video could be seen here.

so i think it must be have one default data which freecad based of that convert the points distance to new units and dont know how it done/

anyway my problem is the cloudcopmare which based of this post have not any specific unit setting :

> Mesurements are expressed in the same units as your clouds.
> CloudCompare doesn't handle units (what we call 'implicit units').
>
> In your case it looks like it's in millimeters? Or fractions of inches
> maybe?!

Now i have two stl file like this:



which give me this output data like this:




And the question is the c2m distance are based of what? ( mm or 1/x of mm ),
so for example the difference for first point of target stl file with reference is -3.303671 mm or etc unit!?

Do i need to ask about the setting of scanner device or can i found it by myself?

The reference stl file could be downloaded from here and the targets to be compared with it also uploaded here.

I guess it must be mm but not sure and asked here to be clarified.


Thanks.

Just look at the scale in the bottom right corner or use the picking tool to measure the distance between two points.

Since you have a jaw between '50' to '100', it's probably mm indeed.

Hi both!

I think I have a similar question. My meshes are scaled in meters, and when I compute the C2M distances I get a Mean Distance of 0.00001 (meters?) and a Standard Deviation of 0.000366 (meters?). But when I look at the histogram I see values that range between -0.0025 and 0.004 (meters?). One specific point was different between both the meshes (it is a fossil that was broken and latter prepared, visually is very difficult to see the preparation), and if you check the colour of the point with that of the histogram you see that it has a C2M distance value of ca. 0.004 (meters?). So, a difference of 4 mm bewteen meshes?? It is not possible, as I said, the preparated bone is very difficult to notice, the difference bewteen meshes should be much lower. What could have happened here?

Btw, Does CloudCompare permit to measure accurately the C2M distance of one specific point? Like this one I am speaking about?

Thanks you very much in advance, and nice start of the week :)

Yes everything should be in meter if the coordinates are in meters.

Well, you can definitely have a low mean or std dev and a few outliers with a high value.

And you can also isolate the points/triangles with big distances with the 'Edit > Scalar fields > Filter by value' tool.