I am having exactly the same problem.
It appears that the cloud data is still in the part file, just not visible. To get it to reappear; I created a new part file from the cloud and saved it. Then dropped this new cloud part file into an assembly that had the original part file/cloud and bam,,, the original cloud shows up.
Additionally, I have an assembly with many part-file-clouds and going through the steps above for one the files, some, but not all of the clouds showed up,,,,
Could it be a graphics card issue? (my card; ATI FirePro V4800 (FireGL) Drive; 184.108.40.20600)
We have this same problem, and we have not found a solution. All of our machines are definitely capable (12 GB memory, Xeon processors, Nvidia K2000), but we have point cloud data disappear, especially when working with point cloud data in parts that are open in assemblies.
An even more important word of caution- If the point cloud data has disappeared and you save the assembly, thereby saving the parts with the point clouds, the next time you open the parts, the point cloud will be permanently removed from the part. It will still show in the feature tree, but Scan to 3D will be grayed out and the data will be gone.
Just make sure you are working from a PDM system so you can reload the older parts with the point cloud data, OR always keep backups of the original point cloud file (XYZ, TXT, etc) so that yu can just import it again in SW. Of course you would lose and cloud thinning and trimming you had done.
Very frustrating, hopefully Scan to 3D someday gets some attention from SW as it has basically been dormant and ignored since its inception.
I have continued using clouds over the last few weeks and discovered; When I load a file that had cloud data, but is no longer visible, by simply minimizing all SW windows and loading a new cloud file in a new part file, the non-visible clouds will reappear.
Eric & James:
I've found the same things you have - if you load a new point cloud the missing one will disappear, EXCEPT if you save while the point cloud has disappeared it's gone forever. The problem for me is that most of my work requires me to hide the mesh while working on the rest of the assembly, so I can't tell when it has actually disappeared, and I end up eventually saving with the mesh missing.
This is really frustrating. Come'on SW...does no one have a answer here? Clearly we aren't the only one's having this issue. Is there something we should be doing differently?
Another interesting thing I've noticed is that you can't hide the mesh/point cloud from within an assembly:
1) If I create a part from point cloud data and import that into an assembly, and then
2) Hide that part from within the assembly,
3) The mesh/point cloud doesn't hide in the assembly
In order to actually hide the mesh/point cloud, I have to open the part file directly, hide the mesh from within the part, and then go back to the assembly.
I'm assuming I must be doing something wrong. I know SW isn't great with point cloud data, but it can't be this bad. This is a serious issue for us, since virtually all of our work involves scan data as reference geometry.
I think I have found a solution to this. I had this problem for ages and just recently had it again which brought me on here.
I went back to my individual part files with meshes in them, and starting with the smallest file tried opening them one at a time. I think the process of opening the part file itself initializes the data different because on my machine the mesh then appears. I do this for each file and then the assembly is good. A pain for larger assemblies, but at least it works. I haven't tried it for massive files, I aim to get the mesh file below 5 Mb before I save. I like the SW Mesh Global Simplification operation because it keeps the mesh dense where it counts, and coarse where it doesn't.
I hope this helps,