Overlap on Sheetmetal

I am using Creo Parametric Release 6.0 and Datecode6.0.6.0

In sheet metal mode, are there any function to set limitation of Sheetmetal to protect overlap each other when unbend?
Now user use Flat pattern preview to check after finish Sheetmetal design.
However, user don't want to fix after check by use Flat pattern preview.
They want some command to alert overlap when during design sheetmetal on that time.

Please share some technique to help me.