Stop Motion OBJ (OBJ, STL, PLY sequence importer) - v2.1.1

Hello, is it possible to bake shape keys for this mesh sequence. I need to import this animation to unity.

Daev,

It’s not possible to bake mesh sequences to shape keys for use in Unity. It’s something I’m looking into, but I don’t have a time line for if/when it might make it into Stop motion OBJ.

If you can use Alembic files in your workflow, I’d recommend checking out the Sverchok addon:
https://github.com/nortikin/sverchok
Video demonstration of converting an OBJ sequence to an Alembic file

OBJ sequence to .abc - Is there an updated video tutorial for this plugin? I’ve followed the steps, but when I import my .abc file back into Blender or UE4, all textures are missing on my volumetric performance capture, and the mesh is a blend of all the frames.

I’m having a similar issue.

Hi Chardell,

OBJ sequence to .abc - Is there an updated video tutorial for this plugin?

When you say “this plugin”, are you talking about Stop motion OBJ? Or are you talking about the Sverchok addon, which I mentioned in the previous post?

Stop motion OBJ doesn’t support exporting to .abc files. It’s something I’ve experimented with but haven’t quite figured out yet.

Sverchok seems to be able to export mesh sequences to .abc, but I’ve never used the addon so I couldn’t help you there. This seems to be the official Blenderartists thread for Sverchok. You might try asking your question there. https://blenderartists.org/t/wip-sverchok-parametric-nodes-for-architects/557250/2263

Good luck!

Hi Justin, thank you for developing such an essential addon (Obj Stop Motion)!
As you might have guessed, yes - I am talking about your plugin.

Regarding export to .abc files, I followed the workaround featured on this post:
https://blender.stackexchange.com/questions/101787/obj-sequence-to-alembic-format

Apparently, if you add a modifier, such as displace to your baked sequence, you can trick Blender into exporting your capture as an alembic cache properly.

However, in this new version of Blender, it appears that modifiers won’t initiate if the settings are zero, and… I was still unable to export the textures. All this leads me to the same conclusion you just explained, that Stop Motion Obj wasn’t originally meant to export .abc. Can confirm, lol.

I am no expert when it comes to any of this, and the Sverchok method seems a bit convoluted and beyond my immediate understanding. Is there another resource that simplifies this a bit? I don’t think I’ve modified a python script in my life, and it appears that his/her tutorial is from a previous version of Blender.

Goal: To import or convert Obj Sequences into Unreal Engine (UE4) as textured mesh(es).

Apparently, if you add a modifier, such as displace to your baked sequence, you can trick Blender into exporting your capture as an alembic cache properly.

Wow, that’s a clever workaround. I tried it out on my end with the latest version of Stop motion OBJ (2.1.0) and Blender 2.83.8 LTS and it seems to be working for me, except that it doesn’t keep the textures. Two differences, though. Try this:

  1. Load your mesh sequence and DON’T bake it
  2. Apply Add an Array Modifier to your sequence and set the Count to 1
  3. Select your sequence and export to Alembic. Make sure you’ve checked “Selected Objects Only”

When I import this .abc file back into Blender, it seems to play the sequence back properly (again, without textures). I don’t have UE4, though, so you might get different results. I’m curious to hear the outcome. Could you share what you find after you’ve tried this?

Edit: I’ve heard that Houdini has this functionality built-in. If this workaround doesn’t work, you might download the free version of Houdini and try it there.

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Thanx for the great addon. I’m using it to export to alembic though, and as others - i’m having trouble with texture uvs, they are exporting just for the first frame. So there is still no solution? If anyone used sverchok workflow for this, does it work for uvs?

@BlackRainbow What’s your process for exporting to Alembic? I wasn’t even aware that was possible. And what software are you importing your Alembic file into?

I’m using this addon to convert fluid obj sequence to alembic. So i’m importing obj sequence with this addon and then after adding some modifier with zero influence i’m exporting to alembic. I needed to export uvs also but it exports them only for first frame.

What if, when you first import the sequence, you check the “Material per Frame” box? Does that help?

Just tested it. Uv is still exported for only first frame (the exported fluid alembic has uvs only in first frame)

So i tried the sverchok workflow. Though i did convert multiple obj meshes to single one, i still couldn’t export alembic with uv. The exported one had mesh with uvs only on first frame. That made me think that maybe blender does not support exporting animated uvs. I made a simple test, and i can confirm - Blender does not export animated uvs to alembic. In case of non-varying vertex count - uvs are frozen on first frame. In case of varying vertex count - uv-s are imported only for the first frame. Apparently this is a bug.

@BlackRainbow Thanks for looking into this. Good to know. Sorry that it’s blocking your workflow.

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Nothing to be sorry about. Your addon is great and works very well. It is blenders limitation not being able to export animated uvs. Still kinda bugs me how this kind of things which are essential in the workflow are not polished in blender. It has taken few years to bring alembic to this point and still so much to bring it to level to work with big guys like houdini or maya. Motion blur support, varying uvs, arbitrary attributes… no big production can go without these.

Wow! Looks like a fix to alembic uv export bug i reported has been commited. Looks like the issue was in both in export and import. Thanks to @sybren for a fix!
https://developer.blender.org/T76132

The thing is – Blender got its first Alembic support as a gift from an animation studio. They didn’t want to develop it further because it did everything they needed. After that Kevin Dietrich has worked on it, and after that I have worked on it as well, so it is already doing more than what an actual animation studio needed. Everybody needs different things.

If something is not working well, please report it. Include an example file, and clear information on how things should work. That’s vital for getting things implemented well, because the Alembic format itself is so under-documented.

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Thanx for clarification. Your work as blender dev is very much appreciated. I can just hope USD integration will gain a bit speed, not as only IO, but as a core structure.

After months of feedback, UX testing, and hard work, I’m just about ready to release a beta version of Stop Motion OBJ v2.1.0. I’ve included a few long-anticipated new features (most notably, the ability to import a mesh sequence that is too large to fit in memory), many bug fixes, and a major overhaul of the UI.
If you would like to be a beta tester, head to https://github.com/neverhood311/Stop-motion-OBJ/releases and get the latest pre-release version (2.1.0.alpha.17 at the time of this post). If you encounter any bugs, please report them on the project issues page (or DM me if you don’t have a GitHub account). Since the UI has changed substantially, first read through the new Quick Start tutorial.

I’m also going to revamp the landing page for the project and I would like to showcase some of the great work being created with Stop Motion OBJ. If you’ve created something cool and would like to see it on the home page of Stop Motion OBJ, either post it here or DM me.

Thanks to all!

One last call for beta testing on version 2.1.0! I’ve updated the documentation and the readme. I’ll release the final version of 2.1.0 in about a week unless some big issue comes up.

If you can spare a few minutes, please try out the latest beta version. Try opening old .blend files, try importing new mesh sequences, and please try out the new Streaming Sequence feature. If you encounter any issues, please report them here or create an issue on github.

Stop Motion OBJ 2.1.0 will be the biggest new release to-date. Let’s make it a great one.

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