Surface not occluding display of some geometry

Hi all,
I have a file which I’ve been working on for a while now and I’ve just recently noticed a display bug which I’ve never seen before. Some of the lines in the file show in their entirety when they should be hidden behind other objects. It’s much like those objects are being displayed in x-ray view, but only those. If I make a copy of one of those objects it retains the same “property”, but any new objects I create, on any layer, behave as they should (are occluded when behind other geometry).

The attached file shows one blue curve which is properly occluded by the surface, and one which is not. The red line is also not occluded.

Any thoughts? Thanks.
Trygve

test.3dm (2.9 MB)

Hi Trygve,

Somehow the draworder for these curves was set.
Use the command ClearDrawOrder to reset the drawing order of the curves.
Also check the functions available to handle the order of drawing here:

http://docs.mcneel.com/rhino/5/help/en-us/commands/draworder.htm

and here:

http://docs.mcneel.com/rhino/5/help/en-us/toolbarmap/draw_order_toolbar.htm

HTH
-Willem

Ah. Great. Thank you. I tried SendToBack, which didn’t work, and so I tossed that out as a possibility. But draw order can’t be applied to surfaces and apparently objects with any draw order at all are drawn first. ClearDrawOrder worked great.