6h debugging: Could not open file "fresnel_copy.exr" Invalid image file "fresnel_copy.exr": Could not open file "fresnel_copy.exr"

[thomas4K5GA]

I spent a solid SIX HOURS today to get a render working on Deadline Thinkbox which always has run fine before. 

I wanted it to render out over the holidays but I dont think this will happen now. 

The scene renders fine in the IPR as well through the normal render in c4d. Again it always worked on deadline the same shot the same scene and it now decided to not work anymore. 

Attached is the debug log.

things I have tried. 

- remove the offending texture, then it fails with the next texture

here is a basic scene which fails:

https://www.dropbox.com/t/03W6xsVvZp8avYys

- rename the offending texture and relinking, same error

- rip out everything and only have the ligth with the Fresnel map as a test. still doesnt work 

- increase max texture load

- restrict Deadline to one render node, my own computer, still fails

- save the whole project with assets into a new folder, fails with the same error

- restart deadline host server

- restart only my client and the client computer

[Stephen.Blair]

There's no path, just a filename.

Could not open file "fresnel_copy.exr"

That means that the only place to look is in the current working directory, and for a Deadline job, that's probably the C4DtoA bin folder.

Why is there no path for the texture? Where is it supposed to be found?

[thomas4K5GA]

That's the default in c4d and the default path is always `./tex/`. This always works over Deadline too. It is also recognized in the UI 

I have been rendering and tweaking this scene for weeks and it only happened now all of a sudden. Rebuilding the scene is days of work. 

[peter_horvath]

Did you update the plugin, Cinema 4D or Deadline? From your post it sounds it has just started happening out of the blue and all versions are the same which were working fine before. Is that right?

Anything suspicious in the deadline log maybe?

I'm not exactly sure how Deadline distributes the assets. Does it copy over the whole project to all clients, including the tex folder? If so, the plugin should be able to locate the textures, just like it does when you run the render locally.

Can you move the textures to a shared folder and use an absolute path? Or if you have a fix project path on the clients, you can add that folder to the texture search path in the Arnold render settings.

[thomas4K5GA · Accepted solution]

@peter_horvath thanks for your response. 

All textures are accessible through absolute server paths over mounted network drives.

Other Arnold deadline renders were still working its only this scene which bugged out. Even if I merged the scene into a new c4d project it failed.

However now it works. I think there must be some weird bugs with tx generation and network access causing file locks also possibly connected with c4d textures . I had still a few texture errors which disappeared when I generated `tx` files and relinked the textures. 

[peter_horvath]

Right, tx generation can cause problems on a render farm if multiple machines trying to access to the same texture. It's always a good practice to link to pre-generated tx files to avoid these issues.