Temporarily using IK to pose what can only be a FK rig?

Ok, I’m posing an armature imported for a game I’m helping mod. I can figure out how to set up the IK just fine, without adjusting the size, name, parents, vertex weights, or any of that stuff of the original mesh/armature. The issue is that when my friend tries to use this armature with 2 additional bones in it, it crashes the game (Rising Storm 2, if it’s relevant).

How can I use this IK rig to set the position of the FK rig, and delete them before export? When I pose the IK rig it doesn’t mean I can simply key frame everything and delete the IK target/remove IK constraint or whatever, that doesn’t work becausing moving the IK target around doesn’t change the rotation of, for example, the wrist in FK terms, even if the wrist rotates.

Any ideas?

Might have answered my own question. Let’s see if this vvorks

Not really working for me :confused:

Well, when creating a rig, you kind of create layers off rigs with each a function.

To put it simple:

  1. deform rig, only the bones deforming the mesh. Corrective shapes are also bound on those.
  2. mechanicl rig, which gives additonnal tools for the animator, including IKs, extra pivots, and so on
  3. controlers, usually with custom shapes, simple to use and keyable

The animator uses only the controllers. And it is the controllers who will operate the different parts of the mechanical, which in turn will move the deform.
When exporting the animation, the resulting animation is baked into keys on each frame on the deform rig, and only this rig is actually exported to the game. This baking process is eaither done manually, or through options in the exporter.

Also, note that once the rig is done, it’s not supposed to be modified anymore.
If there is really a need, then the ideal is to edit only the top levels of the. Because the more you get close to the deform level, the more things you’ll have to edit or entirelly redo.

Thanks for the detailed response.

I only edited the very ends of the chain by adding an IK target or whatever. And I limited the chain length so it wouldn’t touch the root everything is parented to.

The add on sounded nice but I had to use bake action ultimately, which did work i.e. I could delete the IK stuff I added and have the true default armature but the changes I made with the aid of the IK portions are baked into a ton of key frames.

That’s normal, that is the actual goal of baking animations: you ask the software to calculate and write down once for all the resulting animation, so you’re sure that what will be exported is what you did and nothing will get changed or lost in the way up to your import target.
Of course, once it’s done, you can’t modify that. This is something we do only to be exported, not to be saved in the project files you’re supposed to be able to edit at any time.

It’s all about how you do your file-managing.
Usually, we save the project, then do the baking, then export, then reopen the project just before the baking.

In big projects, this problem doesn’t really exist since incremental saves are often used.


Let’s say we want to do the character’s walk cycle. We create a new file named something like character_walk_cycle.blend.
And every time we want to save our work, we will save as a new file named

  • character_walk_cycle_001.blend
  • character_walk_cycle_002.blend
  • and so on…

In Blender, this can be done easily using Save As, you will find a little + icon near the name input, or using the PIE Menus addon which gives you an incremental save button.

This has several advantages:
You can keep track of the evolution of your work, revert to a certain point if you need, and if you ever have a crash, you always have several points of saving to get back on.

Some also save their project into a specific file dedicated for baking, so they don’t accidentally save the baking onto the original project.

Forgive me for just skimming thru this thread, but I get the gist of it…

I once worked on developing an add on to handle this sort of problem. I asked a few game devs and they said it wasn’t needed, FBX export handled that. It basically gave you a deform only rig with animation baked from the full character rig.

I’ll look for the files, let me know if you’d be interested in it…

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Bake action basically does what I need but thanks very much for the offer.