Need help with picked surfaces in an imported feature assembly, for some reason it's zoom dependent

[mmead]

I have a large assembly that was given to us.  It is a CREO file but there is no parametric data it is all imported features.  My problem is when I try to do anything in the assembly or a piece part my picked surface is dependent on the zoom of the object in the screen. 

If I'm looking at the whole assembly at like a 30 foot view and pick on a surface to insert an extrude or a hole or measure from surface to surface it automatically chooses the far side surface.  If I zoom into the surface so I'm at a 5 inch view and do the same button clicks it will choose the nearside surface.

Could this be a config setting?  Hopefully someone has some suggestions

[MartinHanak]

Hi,

use right mouse button + Pick from list command when selecting.

MH

[mmead]

Yeah.  The problem is during the use of this assembly in creo were looking at 1000's and 1000's of clicks between extrudes, measurements, and component placement.  I don't understand why it's default picking to the far side.  It won't be just me working on it and I don't want anyone mistakenly using the wrong side of a component.  It seems to be all of the thinner walls and bent pieces of sheet metal.

[dschenken]

Every selection algorithm has limits. If you have large surfaces separated by small distances the tessellated distance may be zero when zoomed to small scales.

When you are zoomed in the distance in the graphics tessellation of the part becomes greater so it becomes more reliable. When you are zoomed out the distance becomes smaller or zero or negative (depending on curvature) due to the limited precision of the tessellation.

I suppose they should also look at the surface normal, but that adds an additional computation that would slow the process for the 99.999% of the times there is not a tiny separation. It is possible that the selection algorithm doesn't even have access to the surface normal data.

The only thing that comes to mind is to run these sessions with the option "graphics win32_gdi" to avoid using the graphics card as part of the selection process. It will probably run everything else about the models more slowly, but maybe it's worth it. I am nor sure it will work, but it's the only alternate that comes to mind.