When an object becomes invisible when it undergoes “regular” or “diffused” reflection?
There are many reasons for an object to become "invisible".
What was the context of your question?
I would like to know object undergoes invisible for which reflection, Regular or Diffused.
Your question is not translating very well. Can you provide a web pointer to an example of the kind of "invisibility" you are asking about?
Separate names with a comma.