Viewport/OpenGL problems continue

   42167   98   4
User Avatar
Member
246 posts
Joined: July 2005
Offline
I'm still having a lot of issues with the viewport in H13, both in the office and at my setup at home (two entirely different video cards, etc), despite a recent video card upgrade. Home: GeForce 780ti, office: Quadro 4000, both drivers are recent.

“Hidden Line Invisible” in GL 3.3 produces weird n-gon tearing artifacts, see below.

This is how I'd expect it to look (GL 1.1 and GL 2.1), see below.

“Flat Wire Shaded” shades every polygon differently (new behaviour) in GL 1.1 and GL 2.1, see below.

…yet produces a slightly better result in GL 3.3, but still with the “tearing”, see below.

And those are just the tip of the iceberg - I find myself having to switch between “light” and “dark” every few minutes in order to “wake up” the viewport when points decide to stop displaying or polygon selections no longer become highlighted, etc. I find myself doing most of my SOP work in legacy versions (ie. h11) as a result of the frustration.

Attachments:
h13_flat_shaded_tearing.jpg (114.1 KB)
h13_flat_shaded_triangles.jpg (119.2 KB)
h13_hidden_line_correct.jpg (124.4 KB)
h13_hidden_line_tearing.jpg (127.7 KB)

User Avatar
Member
4189 posts
Joined: June 2012
Offline
Is this linux or windows and do you have any model to upload that we can test with? Thanks!
User Avatar
Staff
4999 posts
Joined: July 2005
Offline
My guess, at least with the GL3 hidden line, is that there is either a multiple point/vertex at the spot where the tears are. The outliner attempts to compensate for these cases, but after convexing the geometry it is sometimes difficult to conclusively determine if the edge is an interior edge or not. If you turn on Disp Opts > Markers > Coincident point detection, you can see if any coincident points exist in yor model.

The H11 renderer will not be available in releases past H13.0. Please submit bugs that you find, especially for the GL3 renderer. The geometry in this post would be a good example.
User Avatar
Member
246 posts
Joined: July 2005
Offline
Yes, windows. See attached, the geometry as seen above.

Attachments:
openGL_test_geo.zip (4.3 KB)

User Avatar
Member
246 posts
Joined: July 2005
Offline
twod
My guess, at least with the GL3 hidden line, is that there is either a multiple point/vertex at the spot where the tears are. The outliner attempts to compensate for these cases, but after convexing the geometry it is sometimes difficult to conclusively determine if the edge is an interior edge or not. If you turn on Disp Opts > Markers > Coincident point detection, you can see if any coincident points exist in yor model.

As a comparison, the hidden line geometry displays fine in earlier versions of houdini, and like I had mentioned above, also fine in GL 1.1 and GL 2.1 in H13. That said, those other H13 renderers have their own peculiarities as well (see above, the flat shaded example).
User Avatar
Member
1391 posts
Joined: Dec. 2010
Offline
I had same problem with your bgeo file too !
Even I can't import it in Maya correctly :!:

So I think this problem is not for Houdini , VGA or is not a BUG.

It's normals are so dirty ,When I use Facet SOP to fix normals ,It's display correctly.

Also I think GL1 , GL2 , GL3 using different method and library for rendering objects.

However I agree H11 Renderer in the Houdini 12 is really cool 8)
https://www.youtube.com/c/sadjadrabiee [www.youtube.com]
Rabiee.Sadjad@Gmail.Com
User Avatar
Member
1391 posts
Joined: Dec. 2010
Offline
That's Interesting :shock:
Because I can't import it in the Nuke too !

In the Alembic format both Maya and Nuke can't import it ,But Houdini import it perfectly


If you import it in the Nuke with Obj format ,Then you have same problem in Nuke ! (Maya can't import it with Obj)
https://www.youtube.com/c/sadjadrabiee [www.youtube.com]
Rabiee.Sadjad@Gmail.Com
User Avatar
Member
246 posts
Joined: July 2005
Offline
The normals look pretty clean to me.

Attachments:
normals.jpg (189.4 KB)

User Avatar
Member
4189 posts
Joined: June 2012
Offline
twod
The H11 renderer will not be available in releases past H13.0. Please submit bugs that you find, especially for the GL3 renderer. The geometry in this post would be a good example.

Will GL1 & 2 be deprecated soon too?
User Avatar
Staff
4999 posts
Joined: July 2005
Offline
The GL3 renderer is the primary viewport renderer for Houdini. The GL2 and GL1 renderers came about due to driver issues with OSX & Intel graphics, which are slowly being resolved. They will hopefully not be needed for too much longer.
User Avatar
Member
246 posts
Joined: July 2005
Offline
Hopefully all of the bugs are worked out of the GL3 renderer before the others are depreciated. I find myself switching between the renderers quite often as I'm finding that depending on what I want to see (hidden line, shaded, etc.) some work better than others. I find that switching back and forth between renderers also “wakes up” the viewport and eliminates whatever artifact that might have creeped up while I am working (non-highlighted selections, etc.).

I'd be curious to know if you were able to see any of what I was seeing with my test geometry.

See below, another example of the hidden line “tearing” that I was mentioning earlier - I've emphasized the problem by turning wireframe width up to 10, but you can see what I'm talking about - GL3.3 struggles with n-gons in a way that pre-GL3.3 renderers didn't. Otherwise, it's a simple box SOP with a polysplit SOP.

Attachments:
hidden_line_tearing_example.jpg (118.1 KB)

User Avatar
Member
246 posts
Joined: July 2005
Offline
Update: the “tearing” problem is apparent in any of the display modes that attempt to display edges in conjunction with solid polys (flat wire shaded, smooth wire shaded, hidden line invisible, hidden line ghost). It comes down to the new rendering scheme - it looks like each poly receives a “texture map” now that defines the boundaries with a ramp that creates the illusion of the edges, unintentionally illustrating the behind-the-scenes triangulation in the process in the case of an n-gon.

13.0.288, btw.

FYI his problem also occurs in H12 when the scene renderer is set to GL 3.2. In H12 I'd set the Scene Renderer to H11 in order to avoid these problems, but that option has since been depreciated.

Attachments:
flat_shaded_tearing.jpg (80.6 KB)

User Avatar
Member
246 posts
Joined: July 2005
Offline
Bug reported.
User Avatar
Member
4189 posts
Joined: June 2012
Offline
stu
Hopefully all of the bugs are worked out of the GL3 renderer before the others are

The good part of depreciation is they usually hang around for a version or 2 before being removed. Good fall back option whilst we all move forward.
User Avatar
Staff
4999 posts
Joined: July 2005
Offline
Turns out that these artifacts are occurring on edges on badly tesselated triangles, where the angle between an edge and a non-edge approaches 180°. The distance from the fragment to the edge line is less than the wire width for a portion of the non-edge, as the two are nearly parallel. This causes the bad shading.
User Avatar
Member
246 posts
Joined: July 2005
Offline
…which wasn't a problem pre-H12 and the new GL rendering scheme. So what's the solution? Any chance of re-introducing some sort of back door to the H11 behavior? Again, consider that this is just one of the issues that I'm having, it just happened to be one of the most easily reproduceable. And again, consider the fact that I'm seeing all of these issues on two different setups with two different and very capable video cards.
User Avatar
Member
4189 posts
Joined: June 2012
Offline
stu
…which wasn't a problem pre-H12 and the new GL rendering scheme. So what's the solution? Any chance of re-introducing some sort of back door to the H11 behavior? Again, consider that this is just one of the issues that I'm having, it just happened to be one of the most easily reproduceable. And again, consider the fact that I'm seeing all of these issues on two different setups with two different and very capable video cards.

Backdoor to H11 viewport is there already - set the environmental variable

HOUDINI_OGL_H11_VIEWPORT = 1
User Avatar
Member
246 posts
Joined: July 2005
Offline
Works great, thank you! I guess I'll live in the H11 viewport for the time being.
User Avatar
Member
4189 posts
Joined: June 2012
Offline
Cool - but H11 will be removed, so it's worth using and logging bugs for GL3.3 viewport so it all gets fixed up.
User Avatar
Member
246 posts
Joined: July 2005
Offline
Yup, already done.That said, I'll go back and forth as much as I can so that I can be sure to report any other issues.
  • Quick Links