Seeing internal wires through mesh

I’m trying to help out with WIP, but having a hard time searching before posting. So not sure if this is a bug, or just something I need to tweak.

I’ve increased the mesh. I actually wish I could change the default overall to custom mesh settings every time I open that would override someone elses. I know that’s complicated because if it’s already calculated on a complicated object, maybe not.

OK, so the problem. I’m seeing through mesh objects. Even for corners on the same object, at a distance.

I’m looking at an object that has a straight cut through the bottom section of a cylindar. Looking at the edge so that the mesh Should block the bottom surfaces, I can see a bit of the line through the mesh. Changing angles those get shorter or longer. The same happens for objects Inside the object. At certain angles, I can see wires through. It is most noticeable with cylindrical shapes.
There’s an example. That red object is 100% inside.
Those vertical lines hanging down? That’s the other side of that shape.
And there’s a really bad one.

I feel like it’s a general scale thing. Tolerance is .00124 inches and 1 degree angle. My mesh is set to custom with max edge to surface as .01…

OH. Ok, I changed max distance edge to surface to .001 and it Didn’t remesh. Is there a bug? Am I missing a setting that’s overriding that for some reason? Aaaaand I switched to wireframe, then back and it remeshed. Still didn’t fix the problem though.

I’ve explored all the settings I could think of and couldn’t find anything.

Hi Andy - see if messing with testZBiasFactor helps here.


Thanks Pascal. I had to bring it down to .01. Looks great now.
I would Definitely never have found that without your help. It didn’t even come up in the command line after I typed the entire thing. So I thought, “well, no harm in hitting enter,” and of course it worked.

I assume this has something to do with overall size of the object, and how much you would normally be zoomed in? This Should be in millimeters, but lots of US clients prefer to engineer in inches for some crazy reason. I think they like making math more difficult and memorizing decimals for odd things like 13/32. Why on Earth would I have that memorized!?

Thanks for the help.

Hi Andy- yeah, it is a test command and does not auto-complete - there is no way for you to know about it on your own. That said, note the command line message when the command runs:

“If you constantly use the “TestZBiasFactor” command to fix display artifacts, please send a sample model to
McNeel technical support so we can fix Rhino and get rid of this test obscure command.”



Whoa Pascal. Something happened. I’ll do my best to recall steps.

I’ve opened the file again, and it looks fine. Then i started splitting things into layers using the script you created named ChangeLayerEX (thanks again for that one).
I was choosing the Visible:NO option.
I then turned all the layers back on because I misplaced something.
And then the depth bias scale was worse than before. I could see roughly 1.25 inches into the model. The entire scene fits roughly into a 13 inch box. So that’s a pretty giant scale.

I checked the setting and it possibly reset back to 1. I changed it to .01 and it seemed ok again.

I just found it odd that it looked fine until I created new layers that were hidden, then making them visible again seemed to cause it to mess up somewhat wildly.

Oh, I DID extract some surfaces from a couple pieces of geometry somewhere in there as well. I had some surfaces that were textured, and some pieces were glossy, so I had to split those up for rendering.

Other than that I think that’s it. I’ll shoot more info your way if something else comes up. It just seemed odd that it suddenly changed in the middle of a project.