Creo Simulate > Modeling Structure and Thermal Problems > Regions > Split Surface > To Create a Split Surface Using Manual Selection of Contours
  
To Create a Split Surface Using Manual Selection of Contours
1. Click Refine Model > Regions > Split Surface. The Split Surface tab opens.
2. Click to select contours manually.
3. Click the Placement tab.
4. Click the Split surface collector and select a solid surface or quilt to split.
5. Click the Selected contours collector and select the contours to copy into the Split Surface region feature.
6. Click the Options tab and select an option:
To create several Split Surfaces, one for each selected contour, select For each selected contour separately.
To create one Split Surface from all the selected contours, select For all selected contours together.
7. Click . A Split Surface region feature is created. You can work on it independent of the original surface.