Hidden lines showing through thin walls

[CNSZU]

Hello,

For some reason, NX will show lines that are hidden behind very thin walls. See the attached image for an example. You can try it yourself to see if you have the same problem:

1. create a 100 mm sided cube
2. create a 40 mm thick extruded cut inside the cube which is offset from the cube walls by 0.2 mm.

The cut is entirely inside the cube, but the lines of the cut are showing through the wall. Zooming in will make the lines less visible.

Changing the faceting, line width, or the tolerances of the features makes no difference.
I've upgraded to the most recent certified Nvidia driver (347.52), but the problem persists.

Can someone please confirm if they don't have this problem?

NX10.0 Win8.1 64bit i7-3770K 16GB Quadro2000

 

[mathisudar2007]

Hello,

There is a setting in 'Visualization - Preferences'.
Disable the 'Edge Emphasis' and check(Session settings).

Thanks,
Mathi K

 

[CNSZU]

Mathi, do you mean Visualization Preferences > Visual > General Display settings? Disabling Edge Emphasis makes the problematic lines a little fainter, but removes the silhouette lines, so the end result is slightly worse.

NX10.0 Win8.1 64bit i7-3770K 16GB Quadro2000

 

[JohnRBaker]

It's simple 'bleed thru'. It's a characteristic of how shaded images are produced using today's graphics cards. In other words, there is actually NO hidden-line removal taking place, rather we're simply depending the shaded face in front of an edge hiding that edge, but when they are very close, the pixels of the edge are 'bleeding thru' the pixels of the face, which is why, as you zoom in, the 'bleed-thru' is less noticeable because in effect the pixels are getting smaller so therefore the 0.2 mm distance represents MORE pixels between the edge and the face, thus providing for a better 'hidden edge' display. BTW, if you were perform the software-based hidden line removal none of those internal edges would be visible since the software would know exactly what pixels to NOT turn on. When it's done with hardware ALL the pixels are turned ON, we just depend on them being far enough apart that it doesn't matter. One other thin that will help is to make sure that you've set your display driver to output as high a resolution image as possible since MORE pixels = LESS bleed-thru. When the industry starts to move to 4K displays these sorts of issues will be less common as the pixels will have gotten even smaller.

Now if this issue is preventing you from producing good screen captures for external use as image files, you may need to first use some of the software rendering tools as they do the hidden edge removal with software so there will be NO bleed-thru.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[CNSZU]

Thank you John for the explanation.

NX10.0 Win8.1 64bit i7-3770K 16GB Quadro2000