Ciao a tutti,
Vi posto una interessante discussione sull'utilizzo degli "Smart Lightweight" (Customer Default - Assembly - Site Standard - load Smart Lightweight Data) di NX7.5.
... Per tutto quello che riguarda come si creano etc gli Smart Lightweight: studiate!!!

Non ho voglia di tradurla... sono un pò stanchino ultimamente...
Mettela in Google se non la comprendete bene.

Loading the “smart” lightweight data will allow you to do more things with lightweight data. For example, if you load the “smart” lightweight then you can use “almost all NX commands” including Assembly Constraints, WAVE links, measurements, etc., even if you have lightweight data displayed. Loading “smart” lightweight uses more memory than the default lightweight, but it is still less than if you were using precise bodies.

Let’s assume you have “smart” lightweight loaded and lightweight bodies displayed. Now, suppose you want to do a WAVE link by picking a face from another part. Because you have “smart” lightweight loaded, when you pick the face we know the underlying precise geometry, so NX can do the link. If you did not have “smart” lightweight loaded, then you would first need to fully load the part, then you could do the WAVE link. This is how NX used to work with the older facetted body technology. Facetted bodies were great for performance, but not very useful in terms of modeling functionality. This lack of functionality is now gone, but you do have to load the “smart” lightweight, which is not as memory efficient as not using it. So, basically, it is a tradeoff of memory efficiency vs. modeling functionality. If you have sufficient memory, then using “smart” is a good idea. If you don’t have enough memory and you are not concerned about the modeling efficiency, then you should not use “smart”.

Un estratto dal What's News di NX7.5:

Seamless lightweight loading
What is it?
The new seamless lightweight loading capability lets you select lightweight geometry in almost all NX commands. If the software requires the solid representation to complete the operation, it is automatically loaded. Lightweight geometry that you can select includes faces, edges, and vertices.
Seamless lightweight loading lets you interact and work with lightweight representations as if they were solid bodies, with no need to manually switch representations. In previous releases, you could only use a few commands with lightweight representations; selection of lightweight topology was not possible in other commands.
Use the Load Smart Lightweight Data customer default to control whether the software uses seamless lightweight loading.
When the Load Smart Lightweight Data customer default is active, which means that seamless lightweight loading is in use, some extra data is loaded from the components. As a result, loading an assembly typically uses 20 – 80% more memory than traditional lightweight loading. However, this is still significantly lighter than loading the assembly with exact representations.
Operations on lightweight data generated before NX 7.5 may cause the software to load exact data more often than for representations created or updated in NX 7.5. For optimal performance and memory efficiency, you can refile your pre-NX 7.5 part files using the refile_part utility to update the lightweight representations. See the Utilities and File Management Help for more information about the refile_part utility.

Infine un avvertimento:

One important caveat to this is the effect of using smart lightweight data with large assembly drawings. This caveat was just added to the NX 7,5,3 Release Notes for Drafting:

Lightweight data in large assemblies with faceted representation views
When working with faceted representation views in drawings of large assemblies, it is recommended that you disable the Load Smart Lightweight Data customer default option before creating the views. This option is located in the Customer Defaults dialog box under the Assemblies→Site Standards→Lightweight Representations tab. If this option is selected, exact data may be loaded when dimensioning in faceted representation views.
If you do not want to disable the Load Smart Lightweight Data customer default option, then it is recommended that you set the Preferences→Selection→Rollover Delay option to 2. This will reduce the chance of loading exact data when you preselect geometry for dimensioning.

Apparently, using smart lightweight data in large assembly drawings causes process (timing? memory?) issues. I understand they’re trying to fix this issue for NX 8.0.