Lights and objects disappearing

[uncle pritt]

Hi,
since the 3.00.06 update I discovered this problem. I can't reproduce the exact result with one action, but it's quite annoying.
Some objects and some lights disappear, but in the scene everything is unhided. After closing the VFB I press the U key (unhide in modo) and sometimes it works, or just restart the cpu RT. Really strange thing.

It happens when I open the scene, of a previous working file, or when I modify some materials, both in schematic and in the shader tree, and when I change the render region field.

Maybe it's caused by every vray upgrade I made, this is a project started since the 3.00.04, and some thing is messed up.

Thank you.

[vladimir.nedev]

Can you send me the scene or a stripped down version ?
Are you using Distributed rendering in this case ?

I don't think the state that the "U" key changes can affect V-Ray, unless you use the hide(h)/unhide(u) keys
in "polygon selection" mode. V-Ray will respect these. This state is not saved with the scene, so if you
close and open it, the hidden polygons will be once again visible.

In any case, if you hide polygons with the "h" key, they will be hidden in both the MODO view-port and the V-Ray
render.

I don't think the upgrade from 3.00.04 can affect this, the scenes should be compatible between versions of the plug-in.

Greetings,
Vladimir Nedev

[uncle pritt]

Every object was visible, nothing hided, nor in item or in component mode.
I noticed that if I hide objects (not polygons) with the h key vray doesn't hide the objects, I can still see it rendered, but if I turn off the eye icon in the item list the objetc gets hided.

Distributed render is disabled.

The scene is quite big, can I send you an email?
Thank you.

Maybe I will try to grab a video of what's appening.

[vladimir.nedev]

I noticed that if I hide objects (not polygons) with the h key vray doesn't hide the objects, I can still see it rendered, but if I turn off the eye icon in the item list the objetc gets hided.

Yes, this is normal, unfortunately the MODO API doesn't provide a way to get the visibility state toggled with the h/u keys, when in item selection mode.
Not that I think about it, this might be possible with the new Render Cache API actually.

The scene is quite big, can I send you an email?

Yes, you can strip it down if possible.

Maybe I will try to grab a video of what's appening.

That can be very helpful as well.

Greetings,
Vladimir Nedev

[uncle pritt]

Uploaded the video.
Everything renders correctly. Save, close. Open, render: missing objects. Close vfb, render correct.
This started with 3.00.6 I will try thge same scene also with the 3.00.5.

https://youtu.be/LDwxDJBSJT4

This is the link to the complete file without textures, they are quite big, but I don't think they are the problem. The link will expire friday

http://gofile.me/2lVuB/jL8pBPfD

Thank you.


EDIT: it happens only with the cpu RT, with the render with vray button everything fine.

[vladimir.nedev]

Thank you, both the scene and the video are very helpful.
I can reproduce the problem in MODO 801 SP4.
What version of MODO are you using by the way ?

Greetings,
Vladimir Nedev

[uncle pritt]

I was missing one of the most important information: 801 SP4.
Model created mostly with SP3 with the same problem in 3.00.06 (I'm sorry but I desinstalled sp3 few days ago)

[vladimir.nedev]

I was finally able to take a look at the scene, and here is what I found.
This seems to be a MODO 801 SP4 specific bug (I can reproduce it every time there, and not a single time on MODO 701 SP5, MODO 801 SP3 or MODO 901).
It is also present in the newly released MODO 801 SP5.

The bug happens when V-Ray for MODO tries to get the triangle data for a HIDDEN mesh.
After this, MODO no longer returns any triangles for meshes with sub-division triangles in them.
It is specific to RT, and doesn't usually happen with normal rendering, because currently V-Ray RT will export ALL meshes (even the hidden ones),
so it doesn't need to export them when their visibility changes later on. I might change that in the future. Normal V-Ray rendering will ignore the hidden meshes.

So the work-around will be to
- either have all your meshes visible OR
- apply V-Ray Geometry Properties to all your meshes with sub-division, and enable V-Ray Sub-division there OR
- start RT a few times until the meshes show up in the render OR
- go back to MODO 801 SP3

Sorry, I can't be of more help, but I don't think I can do anything about that bug (beside changing how V-Ray RT initially exports the scene, but that will take
some time to implement).

Greetings,
Vladimir Nedev

[uncle pritt]

Oh, thank you for the reply!

I upgraded to MODO 901 and as you said befor the problem will not be present.
I will send the email for the nightly builds for 901.

Thank you for the support, I hope this could be useful to track some bug.

Regards.
Andreu Polato