Unity x Blender 3.0 Integration #95099

New Issue

George Ing · 2022-01-20T23:39:59+01:00

George Ing commented

2022-01-20 23:39:59 +01:00

System Information
Operating system: Windows
Graphics card: GTX 3080

Blender Version
3.0

Short description of error
Hey folks,

It's George from the Import Workflow team over at Unity.

We've started having users report that Blender 3.0 doesn't work nicely with Unity when it comes to native ".blend" files. In the case of ".blend" files in the Unity Engine we 'secretly' re-spin up a Blender instance on the '.blend' file (by selecting the Windows default program registered for .blend files) and trigger an FBX export under the hood., which we then import.

It seems like in Blender 3.0 the files are possibly now associated with the launcher, and that's causing the Unity Editor issues? We're not quite sure.

We'd love to hear any suggestions about what's changed in 3.0 that might have a knock-on anyhow; and perhaps chat with you about any better ways we can handle this problem space.

**System Information** Operating system: Windows Graphics card: GTX 3080 **Blender Version** 3.0 **Short description of error** Hey folks, It's George from the Import Workflow team over at Unity. We've started having users report that Blender 3.0 doesn't work nicely with Unity when it comes to native ".blend" files. In the case of ".blend" files in the Unity Engine we 'secretly' re-spin up a Blender instance on the '.blend' file (by selecting the Windows default program registered for .blend files) and trigger an FBX export under the hood., which we then import. It seems like in Blender 3.0 the files are possibly now associated with the launcher, and that's causing the Unity Editor issues? We're not quite sure. We'd love to hear any suggestions about what's changed in 3.0 that might have a knock-on anyhow; and perhaps chat with you about any better ways we can handle this problem space.

George Ing commented

2022-01-20 23:39:59 +01:00

Added subscriber: @George.Ing

Supreme George commented

2022-01-20 23:40:28 +01:00

Added subscriber: @George-Supreme

Harley Acheson commented

2022-01-21 02:57:45 +01:00

Added subscriber: @Harley

Harley Acheson commented

2022-01-21 02:57:45 +01:00

Hey George,

Could you explain a bit more what "doesn't work nicely" and the "issues" are that are reported? Ie, an error occurs, no file is imported, it is incorrectly imported? Does this seem to affect all Blender 3.0 users or just some?

The launcher is indeed new, but if you were to start that it should start up the main blender executable, passing along any arguments that you use. I can imagine issues if you "open" the blend file with ShellExecute or ShellExecuteEx, instead of launching the program via CreateProcessA. Do you mind explaining more about how you launch blender and how you perform the export?

One concern about "selecting the Windows default program registered for .blend files" is that some users might have an older version of Blender associated with those files. This association is not done in all installation scenarios.

Hey George, Could you explain a bit more what "doesn't work nicely" and the "issues" are that are reported? Ie, an error occurs, no file is imported, it is incorrectly imported? Does this seem to affect all Blender 3.0 users or just some? The launcher is indeed new, but if you were to start that it should start up the main blender executable, passing along any arguments that you use. I can imagine issues if you "open" the blend file with ShellExecute or ShellExecuteEx, instead of launching the program via CreateProcessA. Do you mind explaining more about how you launch blender and how you perform the export? One concern about "selecting the Windows default program registered for .blend files" is that some users might have an older version of Blender associated with those files. This association is not done in all installation scenarios.

Garek commented

2022-01-21 05:18:00 +01:00

Added subscriber: @Garek

Garek commented

2022-01-21 05:18:00 +01:00

About launcher, it exists since 2.93 so if there is issues with launcher itself they should have been started from that time.

In #95099#1292228, @Harley wrote:
One concern about "selecting the Windows default program registered for .blend files" is that some users might have an older version of Blender associated with those files. This association is not done in all installation scenarios.

If that's the case then one possible issue I can imagine is that user have compression of .blend files enabled and older version of Blender associated as default program. In 3.0 Blender switched to zlib for compression:
https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Core
That files will not load in older versions, user will see message along the lines of "that's not a supported file format"

So if issues reported can be explained by default (old) Blender not being able to open .blend files you can test that by asking user to disable compression and re-save file.

About launcher, it exists since 2.93 so if there is issues with launcher itself they should have been started from that time. > In #95099#1292228, @Harley wrote: > One concern about "selecting the Windows default program registered for .blend files" is that some users might have an older version of Blender associated with those files. This association is not done in all installation scenarios. If that's the case then one possible issue I can imagine is that user have compression of .blend files enabled and older version of Blender associated as default program. In 3.0 Blender switched to zlib for compression: https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Core That files will not load in older versions, user will see message along the lines of "that's not a supported file format" So if issues reported can be explained by default (old) Blender not being able to open .blend files you can test that by asking user to disable compression and re-save file.

Ray molenkamp commented

2022-01-21 06:29:18 +01:00

Added subscriber: @LazyDodo

Ray molenkamp commented

2022-01-21 06:29:18 +01:00

There's a few things that could cause you problems, like garek mentioned the compression format changed, loading a compressed 3.0 file into 2.93 will not work (the other way around is fine though, 3.0 will read 2.x compressed files), if the 2.93 version is still the "default blender", that could cause you issues with some files.

Also the launcher which does exist since 2.93 will make your life, "difficult" depending on how the unity integration was setup, the main difference between the launcher and the old blender process that you used to launch, is that if you are waiting for the process to exit as a sign the the FBX file is ready, this assumption is now invalid, the launcher exits as soon as it launches the actual blender process.

It's really hard to guess what exactly is causing you issues without some further diagnostics or more symptoms that you are seeing

If you want to have a chat, works for me, you can find me most days on blender.chat in the #blender-coders channel, I'm on mountain time (GMT-7) so depending on where you are some scheduling may be required.

There's a few things that could cause you problems, like garek mentioned the compression format changed, loading a compressed 3.0 file into 2.93 will not work (the other way around is fine though, 3.0 will read 2.x compressed files), if the 2.93 version is still the "default blender", that could cause you issues with some files. Also the launcher which does exist since 2.93 will make your life, "difficult" depending on how the unity integration was setup, the main difference between the launcher and the old blender process that you used to launch, is that if you are waiting for the process to exit as a sign the the FBX file is ready, this assumption is now invalid, the launcher exits as soon as it launches the actual blender process. It's really hard to guess what exactly is causing you issues without some further diagnostics or more symptoms that you are seeing If you want to have a chat, works for me, you can find me most days on blender.chat in the #blender-coders channel, I'm on mountain time (GMT-7) so depending on where you are some scheduling may be required.

Etienne Archambault commented

2022-01-21 19:02:40 +01:00

Added subscriber: @EtienneArchambault_Unity

Etienne Archambault commented

2022-01-21 19:02:40 +01:00

Hey guys, thanks for the follow up!
I'm investigating this case with George and the team.
You can find a clean description with this report : https://issuetracker.unity3d.com/issues/blender-could-not-convert-the-blend-file-to-fbx-file-error-is-thrown-when-blend-file-is-imported
I can add that if you never installed Blender 3.0 before, upon installing it re-importing .blend will always fail in Unity. I tested on VMs and it's 100%.

About the blender-launcher.exe, I dont see it in the 2.93 root folder. Was it somewhere else in that version?

Cheers

Hey guys, thanks for the follow up! I'm investigating this case with George and the team. You can find a clean description with this report : https://issuetracker.unity3d.com/issues/blender-could-not-convert-the-blend-file-to-fbx-file-error-is-thrown-when-blend-file-is-imported I can add that if you never installed Blender 3.0 before, upon installing it re-importing .blend will always fail in Unity. I tested on VMs and it's 100%. About the blender-launcher.exe, I dont see it in the 2.93 root folder. Was it somewhere else in that version? ![image.png](https://archive.blender.org/developer/F12814829/image.png) Cheers

Ray molenkamp commented

2022-01-21 19:13:58 +01:00

Added subscriber: @Jens_Eopus

Ray molenkamp commented

2022-01-21 19:13:58 +01:00

I'm unsure if @Jens_Eopus is with unity, but he posted a fix earlier today in D13894: Fix: Launcher: wait for Blender to exit , i can tickle the bots if you want a binary version to test/play with

as for 2.93, you appear to be correct, i am mistaken there, i pulled up the commit f3944cf503 and it's definitely 3.0+ only, sorry for the confusion.

I'm unsure if @Jens_Eopus is with unity, but he posted a fix earlier today in [D13894: Fix: Launcher: wait for Blender to exit](https://archive.blender.org/developer/D13894) , i can tickle the bots if you want a binary version to test/play with as for 2.93, you appear to be correct, i am mistaken there, i pulled up the commit f3944cf503 and it's definitely 3.0+ only, sorry for the confusion.

Harley Acheson commented

2022-01-21 19:29:50 +01:00

This seems to have an easy fix on the Unity side that doesn't require waiting for any fix from us.

When you get the path associated with ".blend" files from the registry, just replace the file name with "blender.exe". This is the same strategy that the launcher itself uses to locate the Blender executable (Get own path with GetModuleFileName, replace file name with "blender.exe", open that with CreateProcess).

This seems to have an easy fix on the Unity side that doesn't require waiting for any fix from us. When you get the path associated with ".blend" files from the registry, just replace the file name with "blender.exe". This is the same strategy that the launcher itself uses to locate the Blender executable (Get own path with GetModuleFileName, replace file name with "blender.exe", open that with CreateProcess).

Etienne Archambault commented

2022-01-21 19:39:54 +01:00

A build of https://developer.blender.org/D13894 would be awesome - I can test it right away!

Thanks guys!

A build of https://developer.blender.org/D13894 would be awesome - I can test it right away! Thanks guys!

Ray molenkamp commented

2022-01-21 19:48:43 +01:00

kicked the bots, the build should popup over at https://builder.blender.org/download/patch/ in the next hour or so.

Etienne Archambault commented

2022-01-21 20:02:57 +01:00

That's great @LazyDodo !
If this ends up working (I'll grab it hot and try right away), would it only exist in 3.1 or is that something that could be backported (if that's a thing in your workflow)?

That's great @LazyDodo ! If this ends up working (I'll grab it hot and try right away), would it only exist in 3.1 or is that something that could be backported (if that's a thing in your workflow)?

Harley Acheson commented

2022-01-21 20:19:13 +01:00

@EtienneArchambault_Unity - If this ends up working...

Then that confirms the issue, but you don't have to wait for us to release that change. When your code gets the associated path to ".blend" files in the registry, just clip the filename off that path and add "blender.exe". That will work immediately for current, older, and newer versions of Blender. It will also work if I personally decide to associate "blend" files with a custom batch file that uses specific arguments.

> @EtienneArchambault_Unity - If this ends up working... Then that confirms the issue, but you don't have to wait for us to release that change. When your code gets the associated path to ".blend" files in the registry, just clip the filename off that path and add "blender.exe". That will work immediately for current, older, and newer versions of Blender. It will also work if I personally decide to associate "blend" files with a custom batch file that uses specific arguments.

Ray molenkamp commented

2022-01-21 20:26:29 +01:00

There is a corrective 3.0.1 release planned for the 26th, but we're cutting it awfully close here, I can't guarantee this will make it in time or that it even will be accepted in this corrective release by the release manager.

Etienne Archambault commented

2022-01-21 22:11:40 +01:00

It works!
So now if I set launcher-blender.exe from 3.1 as the default for .blend, files re-import correctly in Unity.
(And if I set it back to launcher-blender.exe from 3.0, it stops re-importing)

The only tricky thing is that from the moment you install 3.0 (with the installer), or set the launcher-blender.exe from 3.0 as default .blend, the only way you can change it is by invalidating its path (changing the currently assigned .exe name for example).
Only once it is invalid can you then point to a new .exe - otherwise it just silently does nothing.
I'm really puzzled by this behavior.

It works! So now if I set launcher-blender.exe from 3.1 as the default for .blend, files re-import correctly in Unity. (And if I set it back to launcher-blender.exe from 3.0, it stops re-importing) The only tricky thing is that from the moment you install 3.0 (with the installer), or set the launcher-blender.exe from 3.0 as default .blend, the only way you can change it is by invalidating its path (changing the currently assigned .exe name for example). Only once it is invalid can you then point to a new .exe - otherwise it just silently does nothing. I'm really puzzled by this behavior.

Etienne Archambault commented

2022-01-21 22:24:48 +01:00

If a user of 3.0 would set blender.exe as default, would this cause any problem?
Because right now Unity users wanting to use 3.0 would only be able if they force it to blender.exe instead of launcher-blender.exe

If a user of 3.0 would set blender.exe as default, would this cause any problem? Because right now Unity users wanting to use 3.0 would only be able if they force it to blender.exe instead of launcher-blender.exe

Ray molenkamp commented

2022-01-21 23:16:02 +01:00

I have a hard time following how you are doing these things, you should use the preferences panel in blender, under system there should be a button to make this instance the "current blender" it will then be used to launch .blend files. your current 3.0 build naturally won't be fixed by the D13894 build, unless you copy over D13894 's the launcher executable.

I have a hard time following how you are doing these things, you should use the preferences panel in blender, under system there should be a button to make this instance the "current blender" it will then be used to launch .blend files. your current 3.0 build naturally won't be fixed by the [D13894](https://archive.blender.org/developer/D13894) build, unless you copy over [D13894](https://archive.blender.org/developer/D13894) 's the launcher executable.

Etienne Archambault commented

2022-01-22 00:16:05 +01:00

Yeah it's a lot of shenanigans to get the defaults to point to the right exe... It's great that you guys added it as an option within Blender - should help going forward!
I tried using the launcher from 3.1 in 3.0 but it kept launching 3.0 - but it might just be on my side

Yeah it's a lot of shenanigans to get the defaults to point to the right exe... It's great that you guys added it as an option within Blender - should help going forward! I tried using the launcher from 3.1 in 3.0 but it kept launching 3.0 - but it might just be on my side

Jens Ehrhardt commented

2022-01-24 10:10:27 +01:00

I just tested the build and it worked for me.
Setting up the default program via preferences worked fine.
Doing it via "Open with..." is really annoying because Windows only reports the EXEs Productname which happens to be "Blender" no matter whether if it's the launcher or the blender.exe or if it's 3.0 or 3.1

Our current workaround is having deleted all the blender-launcher.exe from all company work stations.
This way it's not possible for any user to pick the wrong "Blender" and accidentally messing up our cache server with screwed up imports, forcing me to clear the cache again.

I just tested the build and it worked for me. Setting up the default program via preferences worked fine. Doing it via "Open with..." is really annoying because Windows only reports the EXEs Productname which happens to be "Blender" no matter whether if it's the launcher or the blender.exe or if it's 3.0 or 3.1 Our current workaround is having deleted all the blender-launcher.exe from all company work stations. This way it's not possible for any user to pick the wrong "Blender" and accidentally messing up our cache server with screwed up imports, forcing me to clear the cache again.

Philipp Oeser commented

2022-01-24 12:03:02 +01:00

Added subscriber: @lichtwerk