I am a relatively new user, and we just purchased Creo. As I am looking to find my way around the menu, I found a command "Model Size/ Bounding Box. When I click on it, I see a green box with a diagonal line from the upper right hand corner to the lower left hand corner. Upon further investigation, the box does not show the limits in X Y or Z. It is longer, wider, and narrower than the model. It can also, not be measures.
Just exactly is the use of this command?
from my experience, the size box is a reference box surrounding your entire models or assemblys which you might consider as the "Packaging" for your product. That means that it should be the minimal box size in which you could put your components in. Unfortunately, it doesn´t really works good. Since int considers datum (planes or axis) "size" as well. So if your datums are larger than the model, this box will be bigger and therefor the diagonal size has no sense at all.
One use of the diagonal size, is to find components in an assembly with a relative size from the Top-Level assembly size. Lets say your assembly has a diagonal of 700mm, you can search for componets with a 10% size, then you will find only pars no bigger as 70mm (from its own diagonal).
Afte 13 year using ProE, thats the only use I have found for this tool. Hope this helps and maybe there can be more comments on that.
Visual bounding boxes can also help you find geometry or feature that is way outside of where you think geometry should be. It will at least give you hint of where to look.
Otherwise, yes, bounding boxes are more an internal feature for "proximity" calculations and quick preview to find the component you are looking for in an assembly. More useful when you are limited in computing power. It also helps determine the LOD (level of detail) to display at zoom factors. Again, internal to the software. What this does mean to you is that you want to be a little mindful when a model is out of proportion to the bounding box it assumes.