Remove Merge From Scene

[KoBeWi]

This PR removes Merge From Scene, which is useless after #34892 was merged.
Hopefully I didn't miss anything.

Resolves #32039 (copy-paste doesn't have this problem)

[RandomShaper]

Makes sense. However, it's a bit frightening, isn't it? 😝

[akien-mga]

I'm a bit concerned that it can appear as a workflow breakage for some users, at least until used to being able to copy paste... but there's still time to try it out until 4.0 is released, so let's remove it and see how the feedback is.

[akien-mga]

Thanks!

[Koalamana9]

@akien-mga @KoBeWi @RandomShaper it was a workflow breakage for me! As I understand, I can now just select all the files in the scene and copy them to another one? Is it a safe workflow?

[KoBeWi]

Yes, it's even safer than the merge from scene, because it automatically makes resources unique when necessary.

[Koalamana9]

@KoBeWi @RandomShaper @reduz The only problem I can't figure out is why the size of my scene is getting so big. Every time I copy a node from another scene containing a mesh, it is completely copied to the new scene, literally all mesh coordinates go directly to the tscn file in PoolByteArray, is this a normal behavior? Why not instantiate the original mesh file?
If I have a large enough number of detailed mesh objects that I want to copy into the main scene to build a level (but I don't want to copy them as separate scenes, I need the mesh directly) why is the mesh literally copied into the scene file? My tscn file is under 400mb, it's very strange...

[KoBeWi]

What version are you using? It sounds like an old bug that should be fixed

[Zireael07]

@KoxaKoxama It's likely making resources unique when it shouldn't, please open an issue with the project attached

[Koalamana9]

This is in 3.5.1 and 4.0b2
Here is my issue #66991

[PetBom]

@KoBeWi

I just noticed that "Merge From Scene" is missing from Godot 4 (Beta 8), and this PR confirms that it indeed is so.

I would challenge the initial assumption of this PR that Copy/Paste will replace the "Merge from scene" use cases.

"Merge from scene" is able to pick resources from a scene file (.tscn, .glb...) without actually importing the scene. This is a really useful feature that allow you to pick say just a mesh from a file for replacement without having to import/re-import a whole scene. I would go as far as suggesting that this is the primary use case for "Merge from scene"

This is a quite widely used use case in my workflow. I see no way that could be done with Copy/Paste functionality, but maybe I'm missing something.

[KoBeWi]

"Merge from scene" is able to pick resources from a scene file (.tscn, .glb...) without actually importing the scene. This is a really useful feature that allow you to pick say just a mesh from a file for replacement without having to import/re-import a whole scene. I would go as far as suggesting that this is the primary use case for "Merge from scene"

I think I don't understand. When you copy a scene instance with any external references, the references are left unchanged. Only built-in references are copied (but merge from scene does the same, except it's bugged).

Did you try if copy-paste works with your use-case or are just asking theoretically?

[Zireael07]

"Merge from scene" is able to pick resources from a scene file (.tscn, .glb...) without actually importing the scene. This is a really useful feature that allow you to pick say just a mesh from a file for replacement without having to import/re-import a whole scene. I would go as far as suggesting that this is the primary use case for "Merge from scene"

I must say I don't understand either. I've used copy and paste to do exactly this (extract a single mesh instance from a glb file)

[PetBom]

Ok. Maybe I'm explaining badly. Let me try again. Here's an example 3.5 scene to show my workflow:

Notice that I do not have an instance of the tree.glb in the project node tree. It is imported but not instantiated anywhere in the project. If i now right click the project node tree and use "Merge from scene":

Select file to import from...

Select node(s) to import...

And the selected node gets merged into the project node tree.

So this is the use case I'm trying to describe, and that I believe is missing from the Copy/Paste solution. I see no way to do the same maneuver without actually creating an instance of the tree.glb in the project node tree.

I could see ways that you could implement something similar using Copy/Paste instead. If you implemented Copy from the Advanced Import view Node tree.

As I've manly used the 3.5 "Merge from scene" to actually pick up different meshes for bone deformation using the same skeleton (Multiple versions o character created in blender as separate .glbs let me pick up the desired mesh and merge it in to the instantiated version of the "master" scene for that character) i could see how this specific workflow could be realized in 4.0 using something like Animation Retargeting. But i still think there are many other usecases where "picking up nodes" from file is really useful.

[Zireael07]

That's exactly what I did with copy and paste. Open the glb, copy and paste, voila! No need to "add to project node tree"

[PetBom]

Alright. I think I get it now! :) So to adapt the workflow to 4.0 you would go:

Right click tree.glb in File System and select "New Inherited Scene"...

Right click "Copy" the selected node in the Inherited scene node tree...

Then "Paste" into the project node tree...

And, voila! There we are!

And then just discard the unsaved scene tab.

Yeah that works. For users accustomed to "Merge from scene" (like me) it's not super obvious but once explained it makes sense. I think that it was "New Inherited Scene" that threw me, as instantiating a scene was what I was trying to avoid. Thanks for clarifying. I'll just leave this here if someone else stumbles along with same question ;)