When you first open a Part in an Assembly view, we rely exclusively on the stored faceted representations (equivalent to 1/2 pixel and 8 pixels chordal tolerance @ 1000 pixel screen size) for both on-screen display and Inventor Studio rendering.
The finer of the two versions (1/2 pixel @ 1000 pixels) means that the straight lines that approximate curved edges deviate from the true curve by no more than 1/2000 of the extent of the whole part. For a large part like a long pipe with small holes, this can make the holes look pretty rough.
If you do anything that causes the B-rep (the underlying precise mathematical boundary representation of the Part) to be loaded, we refacet as needed to keep to the on-screen tolerance requested on the Tools > Application Options > Display tab, DisplayQuality: smooth = ½ pixel, medium = 1 pixel, coarse = 3 pixels, so if you zoom in on a small section of the part, we will refacet it to look good at that zoom.
To get B-reps to load usually requires doing something like editing the Part. (We try very hard NOT to load B-reps otherwise, to keep memory from filling up with things you’re not working on.)
In R11 there is a registry setting that tells Inventor to go ahead and load B-reps just for the purpose of doing finer faceting whenever the Display Quality is set to “Smooth” (see above). In HKEY_CURRENT_USER\Software\Autodesk\Inventor\RegistryVersion11.0\System\Preferences\Display
“Faceting Options”
change this value from 0x00000042 to 0x00010042
Do this when Inventor is not running.
Now, run Inventor and set the Display Quality to "Smooth". Then, open your assembly and zoom in on the end of a pipe - it should (after a bit of thinking), look smooth. When you don't want to spend the extra time refaceting, set the Display Quality to "Medium".
Inventor Studio inquires the available set of facet levels of detail (LODs, not to be confused with Assembly LODs) through the API and chooses the finest available one for its renderings. However, the API only returns LODs which are “complete”, meaning there’s a faceted rep for EVERY face in the Part. If you’ve zoomed in on the Part, we have only faceted the faces in the current view, so that new LOD is probably not complete. So, Studio may end up getting a coarser LOD than what you see on screen. The Inventor Studio developers are aware of this issue.
To get around this issue, rotate the zoomed in view so that any parts suffering from this effect (like your long pipes) lie completely in the window – i.e. look at the pipe end-on. After that, you can reorient the view as desired for rendering and your Studio renderings should have smooth faceting, just like the on-screen display.
BTW -- None of this is affected in any way by your graphics card or driver.
