'Ghost' Mesh appearing in Minetest

[j0j0n4th4n]

I have been messing with mesh models recently for a mod I've been working on when something really weird start happening. The animated model looks normal in Blender(2.93) but when I load the exported .b3d into Minetest as the player model, I get the model I see in Blender plus a duplicated model offset to waist height.

Here is how it looks on Blender:

Screenshot at 2023-05-22 13-08-27.png (319 KiB) Viewed 459 times

Here is in Minetest:

Screenshot at 2023-05-22 13-04-20.png (832.58 KiB) Viewed 459 times

I don't know if this is a Blender problem, but I've made other models following the same steps and this haven't happened before.

[GreenXenith]

It looks like you've got another mesh in Blender there called "Beel"? It has the same object count so my first guess is you just have a duplicate mesh there.

[j0j0n4th4n]

'Beel' is actually the mesh, while the other collection is the armature. I made the mesh in Blockbench and exported as obj.

I took the model with elbows and knees made by stu, unparented the mesh and deleted it to keep just the armature then imported the Beel obj into a separed collection and parented to the armature with automatic weights, I painted the weights correctly.

I do think there is a mesh duplicated... somewhere, but I'm not certain on where. I try deleting the Beel collection and exporting but that just leave an invisible player instead. The mesh I'm using is not a single mesh but 10, I believe the '10' that show on the armature is just the linking of the two collection and not an actual duplicate, but I may be misunderstanding something:

Screenshot at 2023-05-23 10-54-09.png (296.75 KiB) Viewed 378 times

But then again, if it was a duplicated mesh on Blender wouldn't the extra mesh show up in the viewer?
I will leave the .blend file with the texture here, I don't use blender much so I may have missed something if you are more experienced then you may be able to find what is wrong

model_beel.zip

(133.83 KiB) Downloaded 9 times

[Blockhead]

I tried exporting the model and texture straight up to ~/.minetest/games/minetest_game/mods/player_api/, but the model came out wrong, seemingly only the torso was exported, and also it moved up and to one side much more exaggerated than the Blender animation would suggest. Sorry, no help!

Blender 2.93.16-linux-x64 on Debian.

[j0j0n4th4n]

That is strange, I've been using the Blender 2.93, in Debian too...

Which version of Minetest are you using? I'm compiled Minetest 5.7, so that is the version I'm using.

Hmm... I haven't uploaded my mod into github yet, I was hoping to finish Beel and another model first, but since that is what I've been using to run the custom models I will leave the file here (just in case of some incompatibility with player API):

model_change.zip

(613.75 KiB) Downloaded 6 times

You can swap the model by replacing the model in the line:

Code: Select all

 custom_beel	= {"character_beelf.b3d"	, "character_custom_beel.png"	},

or by adding a new pair of model and texture into skinList and replacing the line:

Code: Select all

local currentModel	= skinList.custom_beel

by your pair.

[Blockhead]

Minetest 5.8.0-dev-5cd6a22d
Debian bookworm (12 testing)
Blender 2.93.16-linux-x64 portable
io_scene_b3d plugins tried:
The one that seems to ship with that version of Blender
https://github.com/VirtualBrightPlayz/io_scene_b3d
https://github.com/GreenXenith/io_scene_b3d/releases

The version you provided looks like your provided screenshot, but I can't get the same export result.

My export still looks the same as my previous post when I re-export your .blend over the top of beel_custom_kneebendable.b3d Well, almost the same. Now it maybe looks like it has a head embedded in the torso. I'm at a loss as to why we get a different export export result. B3D has made us suffer enough - previous rant thread of mine :( It especially seems to hate working with animation and bones.

And I'm almost certain this is an export problem, because I also went over the objects in edit mode and applying merge vertices by distance, and there were no vertices removed. The fact we get two different results is also suspicious.

Is there an easy way for you to maybe merge the different objects into one object but retain the animation? I would give it a go but I'm really not an expert at animation.

[j0j0n4th4n]

My export still looks the same as my previous post when I re-export your .blend over the top of beel_custom_kneebendable.b3d Well, almost the same. Now it maybe looks like it has a head embedded in the torso. I'm at a loss as to why we get a different export export result. B3D has made us suffer enough - previous rant thread of mine.

That is really strange. After your other comment I redownload the zip file just to check if I had sent the right model, I had but weirdly after I exported as b3d it was working as normal, but that was the same file!
Here is a screenshot:

Screenshot at 2023-05-24 12-44-38.png (670.3 KiB) Viewed 305 times

I'm using:
Blender-2.93.4 with io_scene_b3d plugin however I installed a while ago so I don't recall where I got it. I believe it was the GreenXenith version but regardless, if the difference were due to Blender you should still see the same exported mesh in game, I honestly don't know why we are having different results.
I'm still using Debian 11(bullseye). but I don't think that could lead to such a difference.


I have seem your other post on the state of b3d and I agree that we need better tools, Blockbench is very easy to use but it doesn't export as b3d which is a hindrance to making animated models.

Is there an easy way for you to maybe merge the different objects into one object but retain the animation? I would give it a go but I'm really not an expert at animation.

I also not very good with animation in blender, but I imagine that should be trivial, shouldn't it?
The whole animation is in the armature, so at worst is just a matter of unparenting them, merging the meshes then re parenting the mesh to the armature although that usually require fixing the bone weights in the head and torso, which is a bit annoying. If you wanna I could do that but I'm not sure if it would change anything...

[Blockhead]

I'm using:
Blender-2.93.4 with io_scene_b3d plugin however I installed a while ago so I don't recall where I got it. I believe it was the GreenXenith version but regardless, if the difference were due to Blender you should still see the same exported mesh in game, I honestly don't know why we are having different results.

It's most likely at this point something weird with the plugin like whether you have a certain object selected at export time. Not fun.

Is there an easy way for you to maybe merge the different objects into one object but retain the animation? I would give it a go but I'm really not an expert at animation.

I also not very good with animation in blender, but I imagine that should be trivial, shouldn't it?
The whole animation is in the armature, so at worst is just a matter of unparenting them, merging the meshes then re parenting the mesh to the armature although that usually require fixing the bone weights in the head and torso, which is a bit annoying. If you wanna I could do that but I'm not sure if it would change anything...

I know that the B3D exporter has had trouble with multi-object .blend files and with non-triangular meshes, so it's my best bet. Long odds though. Didn't you say export worked fine though?