CloudCompare forum

Another question...

I want to align cloud and mesh. My cloud is an export from naviswork (exported in feet) and my mesh is an FBX export from Revit(exported in mm). I have found that when I upload both files on CC the export from Naviswork opens in the right co-ordinate/scale but the FBX file opens in the wrong co-ordinate and it is also a lot larger. I have aligned the both files and also done ICP (both with the 'adjust scale' box ticked) but the mesh still comes out slightly smaller than the cloud. Bear in mind I am using the cloud as my 'reference'.

I have also tried to scale my mesh to my cloud by using the multiply/scale but I don't really understand how that works. I have assumed that since the cloud (naviswork file) has clearly opened in feet then I should scale my mesh down by converting the measured distance between the cloud and the mesh into feet. Would this work?

Also, the measured distance between my cloud and mesh is 323

I am not sure if this is clear enough for you to understand :?

Indeed, if you know that units of both clouds, you should definitely scale one of them (if you want to scale the one in meters, then you should simply scale it (by a coefficient of 3.28084 if I'm not mistaken).

And you should do it before anything else, as it might change the mesh position (apart if you use the 'keep in place' option, but it's only the center of the bounding box that will be fixed in this case).

Another warning: if you use a mesh as the 'aligned/data' entity in ICP, pay attention that CC will in fact consider it as a mesh by sampling points on it. This number of points might be insufficient therefore it can be better to do it yourself (with 'Edit > Mesh > Sample points') and use a big number of points. Then use this sampled cloud as data/aligned entity. And eventually you'll have to use the output scale and registration matrix on the original mesh.