How to orient normals outward or inward

Grigory Zhivotovsky wrote:

JMB wrote:
Hello,

How can one orient the normals of a 2D/3D mesh all in one direction?  I see the Modifications -> Orientation -> Face/Volume, but I see no option to specify the direction.  Which way will they be oriented if I click the "Ok" button?

JMB

Hello,

It is very important to have the same orientation of elements. Different orientation can result in errors when you apply distributed load depending on normal direction.  To check orientation in GUI look at faces color.  Colors of front face and back face are defined in preferences Mesh – Mesh.

 
To change orientation use the following scenario:

1.  Click menu  Modifications -> Orientation.
2. Activate radio button Face or Volume depending on type of elements you want to modify. 
3. Select entities you want to modify.
4. Click Add button (list of selected entities appears in dialog box)
5. Click OK or Apply  button (orientation and correspondingly color will be changed)

Best Regards, 

Grigory

Hello Grigory,

Thank you for your detailed reply and explanation.  I was aware of the importance of uniform orientation of elements, however I have another question.  In the Modifications -> Modifications of orientation, there is a choice for Face or for Volume.  What does the volume option do?  I tried it on a tetrahedral mesh and it seems to make no difference to the color of the faces.  So far I am not aware of an FEA pre-processor changing the inward or outward pointing of normals for any 3D elements.  I have known them to always point outwards.  Am I mis-understanding or not understanding what Salome 3.2.2 does?

Regards
JMB