preprocessing in salome

Hi, I have some problem getting along with salome as preprocessor. After a first look at salome It looks like a powerfull tool but I am having trouble getting up to speed...

Say I have a relatively large 3d mesh and I want to add some shell elements close to a face of the 3d mesh. It is convenient to show only part of the mesh during the work. Therefor I choose ”show only” that face. Now if I create any new elements they will become invisible since only the ”show only” face is visible. I have found no easy way to add the created element to existing groups. Thus in a large model it becomes very time consuming to make the new element visible again, so the work can continue...

If I want to add a seg 3 element (that i can later on use to revolve/extrude into quads and tria6) I can pick on the first and the last node but the mid node have to be entered by hand. That means I have to find that node number which is time consuming. I know I can create a seg2 first and later on convert it to seg3, but that also means that all my elements will become second order element, not just the seg2 element.

Adding nodes is a lot of work typing coordinates. I dont understand the link beween geometry and mesh. If I have i node i can not create a point at the same position just by picking on the node. If I have a point I can not add a node to the position of the point. Is it possible to project elements/nodes onto geometry?

Ok, I understand my questions are not so clear, but as I sad I can not seem to get things done in salome right now. I typically want to revolve, extrude (and create the guide elements(or geometry if that is how to do it) for these operations), offset elements, project, greate groups, display elements/hide elements and so on...
Do you have any tips/tricks do get things done? which buttons/functions do you use?

Kind regards,
mihe

One simple axample:

Say I want to create a node at a center of a hole in my existing 3d mesh.
1. create a circle (geometry) from three nodes around the existing hole
2. preate a point at the center of the circle
3. create a node at the point


I can not understand how to do step 1 and step 3. Where is the connection between geometry and mesh?