Materials disappears the next day

[John_Do]

Yeah I know, it sounds really weird, I can't describe the issue more accurately. I work on a scene for 3 days, and every morning when I reopen the scene saved the previous day, all materials are missing, gone ! With the render outputs. But I won few environments slots, crazy.

This is the Shader Tree after the "bug".



The materials and textures are gone but still in the Clip Browser, and the Texture Locators are still in the scene.



I tried some things to replicate the bug :

- create materials, save the scene, quit and restart Modo : OK
- create materials, save the scene, quit, reboot, and restart Modo : OK
- copy paste the scene content in a new file, create materials, save the scene, quit and restart Modo : OK

So I can't to reproduce the bug, but it happens every day. Yesterday I did incremental saves of the scene but it didn't change anything, all the files have the same problem.

I work with a nightly build ( 2016-01-15 ) and have tried to reopen the scene with a stable build ( 3.01.01 ) but the materials still missing.

I post this here but maybe it comes from Modo or something else, anyway it's a really annoying bug.

[Margarita.Stoeva]

Hello!

I guess it may be related to a problem with MODO saving scenes with too many ptags reported in The Foundry Community.
Could you try the temporary fix they suggested ("select all your meshes, and then create a Polygon Part") and tell us if it worked with your scene?
http://community.thefoundry.co.uk/di...=909750#909750
Thank you!

Best regards,
Margarita

[John_Do]

Hello,

Thank you for the fix, but it doesn't change anything, the materials layers are still missing. The part and materials tag are still in the scene but retagging the meshes with these same tags simply create a new blank material.

Also I noticed this, the shader item moved below the Scene Item.

[vladimir.nedev]

Did you try saving the scene after you have removed the "part" tags and then re-opening ?

I am pretty sure this is not a V-Ray for MODO bug, as we are not doing anything "hacky" with our materials to cause this kind of behavior.

I am not sure if it was the Power Translators import tools that import meshes with a lot of "part tags".
My guess is some part of the MODO code is overflowing in this case, maybe even something in the .lxo format.
It is possible that the scene is just corrupted and can't be recovered.
They don't explain what the issue is, so we have to guess.

How did you create the scene geometry, did you import it from somewhere ?

Also, MODO seems to behave flaky when you "open" a scene that is not .lxo, for example .obj or .fbx.
You should always "import" non-lxo scenes, just to be on the safe side.

Greetings,
Vladimir Nedev

[John_Do]

Yes I tried the fix and restart Modo, but the issue is still here.

I am pretty sure this is not a V-Ray for MODO bug, as we are not doing anything "hacky" with our materials to cause this kind of behavior.

That's what I was thinking too, in addition I never have serious issue with V-Ray since the beta opening, but with Modo it's a different story. What a bad idea to buy a software day one -_-'

The scene is pretty basic and built in Modo 902, no CAD import, .fbx, .obj or fancy stuff. The furniture meshes were created in Modo 801 and saved as .LXO, then reimported in the main scene. But previously modified in 902 and saved. Basic !

It is possible that the scene is just corrupted and can't be recovered.
They don't explain what the issue is, so we have to guess.

So I am really embarassed, I already recreate all the materials once and lost everything, not very profitable. I have to get in touch with TF and cross my fingers to don't see this bug happen again.

[vladimir.nedev]

Do you have MODO 902 SP1 ?
http://community.thefoundry.co.uk/di...x?f=3&t=118824

The release notes say it addresses a file corruption issue.

If you have the scene that doesn't open correctly, it will be helpful to send it to The Foundry.
You can send it to me as well, just in case.

Greetings,
Vladimir Nedev

[John_Do]

Yes I already have SP1 unfortunately, so it's another bug. I'll try to reinstall Modo and I hope it will fix the issue.

I will send you a link by PM to download the scene, the scene is broken from a specific version of the scene.

[vladimir.nedev]

So, I took a look at your scene using a MODO SDK sample that dumps the contents of the .lxo file.

It seems the only thing that is missing in the corrupted scene are the parent-child relationships between the "Render" item and its direct children (masks, folders, materials).
You should send both scenes and this information to The Foundry. It will hopefully help them find where the bug is.

So I wrote a simple command that finds all "texture layers" (this is basically everything that can be part of the shader tree) that don't have a parent and re-parents them to the "Render" item.
Here is what's the result after executing the "vray.fixShaderTree" command on your broken scene :


The direct children of the "Render" item are no longer in the correct order, because this information is lost. You will have to manually re-arrange them.
Does the shader tree look as expected ?

Also, use the command only on a broken scene, as it may create problems.
For example, it will parent "Item shaders" to the "Render" item, which is wrong.

The command will be in tomorrow's nightly build (the one from 2016.02.03 ).

Greetings,
Vladimir Nedev

[John_Do]

Woh, really great, thank you a lot to looked at the file ! I will download the last nightly build and try to recover my scene, the materials are in bad order but it will be easy to fix it.

I will also send the file to The Foundry today but have you any idea of what has triggered the bug ? I have never had this bug before and this scene is really basic. Maybe a specific 902 bug ?

[vladimir.nedev]

The nightly builds failed, I've fixed the issue and restarted them. There should be a 20160203 folder when they are done.

I would guess importing one .lxo scene into another might have caused the issue. I've seen scenes with 2 "Render" items or render outputs that are completely disconnected from the shader tree.
Maybe it's safer to copy-paste the geometry/materials from one scene to another, instead of importing a whole .lxo scene.
In the latter case, there are some items that need to be unique (Render item, environments folder, etc...) and maybe there is a bug somewhere in the import functionality when handling this.
That's just a guess though.

Greetings,
Vladimir Nedev

[John_Do]

A big thank you for the fix, I've testing the nightly form 2016-02-06 and it works perfectly fine, I wouldn't have to redo all the materials from scratch I have sent a mail to The Foundry last wednesday and still no answer.

[Robert]

A side node on 'to many p-tags', I often get many of them do to CAD import, like 400.000 or more. They don't corrupt a scene. But in general they make scenes slower do to statistics need to create a list with all of them and cost a bit of memory.

[vladimir.nedev]

A side node on 'to many p-tags', I often get many of them do to CAD import, like 400.000 or more. They don't corrupt a scene. But in general they make scenes slower do to statistics need to create a list with all of them and cost a bit of memory.

Yes, also many "part tags" can currently slow down the export from MODO to V-Ray quite a lot ( this additional time shows up in the "Translating MODO scene to V-Ray" part ).
I plan to optimize this in the future, but for the time being, it is best to clear up geometry, so it doesn't have a huge amount of unused material/part/selection tags.

Here is more info on this : http://forums.chaosgroup.com/showthr...336#post650336

Greetings,
Vladimir Nedev

[John_Do]

Hello,

Just to let you know, the bug happened again, this time on my shaderball scene. The scene materials were locked in the ST, but it seems it was useless because they disappear in Modo secret maze ( even after using the vray.fixshadertree command ). But the others materials are back.

I didn't import mesh through the Import command but with simple drag-n-drop between the two scenes in the Item List, a bit annoying. I sent a bug report to TF about this and will update it, I hope they will find out where does come from the issue.

[BVA]

simple drag-n-drop between the two scenes in the Item List, a bit annoying. .

Modo break all the links in schematics when an item is moved from one scene to another. This is REALLY frustrating as a lot of vray materials need be be done in schematics. I have also bugged this and spoke to them (TF) about it a few times without success. It is a workflow killer!