Jump to content
Terry Smith

Weird horizontal lines in OpenGL render.

Recommended Posts

These lines are appearing in my openGL renders at certain zoom distances from the drawing. I'll be zooming in and then all of a sudden they'll appear, then they'll go away.

"well why don't you just zoom until the lines go away?" While that is a workaround, the lines appear while the camera is "sitting" in a seat in the back row of the theatre.


Horizontal Render Lines.png

Share this post

Link to post

You have Lines Option on and nearly perpedicular view to the View ?


You could try background OpenGL and Hidden Line on top in a SL Viewport.

But as far as I know HL has also problems with "1 Point Perspectives"

(called Central Perspective ?)

I assume the wired Lines would go away as soon as you start to rotate your view

a bit sideways, so that it will be a true 2-3 point perspective.


May not help you anyway ...

Share this post

Link to post
Posted (edited)

Usually this indicates overlapping geometry. Check if you have intersecting objects or doubled up objects. When two solids occupy the same x, y, z space, VW struggles to know which to show, so you get that look in open GL. 

Edited by EAlexander
  • Like 2

Share this post

Link to post

It does often indicate overlapping geometry, so it could be that, but I've also experienced this sort of thing as a graphic glitch. If so it may go away after a restart.

Share this post

Link to post
11 hours ago, EAlexander said:

Usually this indicates overlapping geometry


Yep, I agree... known as z-fighting.

Can you look at one more thing though? I've noticed some oddities in open GL drawing when your geometry in a long way from the internal origin.

Set a 3d locus to 0,0,0 and then zoom to all, and see how far away you are... if it's a long way, get everything to the origin and have another look.... that might solve it.

  • Like 1

Share this post

Link to post

RussU: (a few months later): I was having same problem on a file as the above folks. I checked your suggestion and it did the trick. I was stymied because I have other files that worked just perfect. As it turned out I had imported some symbols or objects from other files of vastly different scales and some of them ended up in 'outer space'. In addition to the striated lines, I had very poor OpenGL rendering. Losts of my object edges had wavy/scalloped edges. Your solutions solved both problems.

Kind regards,

Share this post

Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


7150 Riverwood Drive, Columbia, Maryland 21046, USA   |   Contact Us:   410-290-5114


© 2018 Vectorworks, Inc. All Rights Reserved. Vectorworks, Inc. is part of the Nemetschek Group.