Why Are Grading Groups Necessary?

[Okkin94]

IF objects on different sites do not interact, but objects on the same site interact regardless of whether they are in different grading groups or not, what is the reason for different grading groups? Why are they necessary if you can keep interactions separate by site? It seems like an extra (useless) step to put them in a different groups if they do interact?

[Kevin.Spear]

You have to evaluate your project to answer this question. Is it one proposed graded area or is it several disconnected graded areas? If its one continous graded area, would you define it in c3d in pieces? If the answer to either of those questions is yes, it means you can benefit from using multiple grading groups. 

Remember, there are 2 functions that apply to a grading group:

1 - automatic surface creation; its not uncommon to take a proposed surface and create it in pieces that get pasted into a composite FG

2 - gtading volume tool; again applies to a specific grading group or selection set in a grading group

Hope this helps!

Kevin