Problem Exporting Rig and Skin in Maya

Rigging
1

Hi everyone, I’m knew here, just graduated from a video game design school and working on my portfolio, so if these are newb questions, please be patient with me. I tried doing a search but I couldn’t find anything related to my problem.

Anyway here is the problem, when I export my bind rig and mesh via FBX I get 2 warnings, one is a Skin Definition Warning and another is a Complex animation baked warning. The first one is giving me problems because it says that the plug-in is unable to find the bind pose for: such and such bones (28 of them). No bind poses in the hierarchy containing the object will be exported.

The second warning has never given me a problem in the past.

Anyway when I bring the FBX file into UDK the vertices on the model are a complete mess, which seems appropriate for a skin definition problem.

I have never gotten the Skin Definition warning before and I’m not sure how it came to be.

Anyone come across this problem before and have a solution? As long as I know what the problem is I do not mind restarting the rigg over and reskinning, however I’ve just hit a stand still with my portfolio because I have no clue what is going on and I’m afraid I’ll make the same mistake again later and have to restart anyway.

Any help will be much appreciated, and if more information is needed I’ll upload the rigg and you can take a look.

EDIT: I believe I fixed my problem. I detached the skin and rebound it, but I unchecked the remove unused influences option in smooth bind. Now I can save, open and close and export whenever and I don’t get the skin definition warning! Thanks to everyone who replied and offered a solution. Now I’ll have to reskin the mesh but at least I’ll be quicker since it’ll be my 8th time skinning it haha.

2

Quick fix would be to export the weights, (use Maya’s tools or find a MEL script on the web to do it), delete the skinCluster, re-skin, and import your weights again.

3

Take a look at the dagPose command. As long as you can get your rig into what should be the bind pose, you may be able to correct it “under the hood” for the problem bones.

The “complex animation” warning isn’t really an issue in most cases. It just means that some of the joints are controlled by stuff that fbx can’t export such as an IK setup or other inputs. In fact, it is basically impossible to make a rig with decent controls which won’t throw this warning.

4

Thanks for the advice guys. I should also mention that the mesh is broken up into several pieces. I’m wondering if that is a problem. Also when I binded the mesh I chose remove unused influences. Could this be what’s causing the skin definition problems?

@JayG: I’ve found that I the skin export and importing doesn’t work 90% of the time in maya so I may have to find a custom one. Also what do you mean by delete the skinCluster, and where do I do that?

@btribble: Not sure what the dagPose command is but thanks, I’ll look into it. as for the complex animaiton warning, I figured it wasn’t much a problem since my animations imported well enough into UDK before, but thank you for explaining what the warning meant.

I’ll try to implement these solutions and I’ll get back to you guys if I’m still having problems. Thanks again.

5

The skinCluster is basically the node that connects the joints to the mesh and houses all of the skinning information. There will be one of them for each piece of geometry, most likely named “skinCluster1”, “skinCluster2” etc. You can delete them by using MEL, “delete skinCluster1”. If you select the mesh, you can see the name of the skinCluster in the INPUTS window in the Channel Box.

6

To get rid of the animation error, just export what you absolutely need. Usually its the skinned bones and the skinned mesh, so you can make a selection set and export selected. Its not essential but if the error annoys you its a quick fix.

7

[QUOTE=JayG;10380]The skinCluster is basically the node that connects the joints to the mesh and houses all of the skinning information. There will be one of them for each piece of geometry, most likely named “skinCluster1”, “skinCluster2” etc. You can delete them by using MEL, “delete skinCluster1”. If you select the mesh, you can see the name of the skinCluster in the INPUTS window in the Channel Box.[/QUOTE]

Oh I see now, but once I detach the skin from the bones it deletes the skinCluster inputs anyway. I also haven’t been able to successfully export and import the skin weights. I even exported the weights of each individual mesh using the default settings. Once I try to import the skin weights onto the rebound mesh, the deformation results are no different from the default bind. I even see maya processing the skin weights, but nothing seems to move differently.

[QUOTE=animation109;10384]To get rid of the animation error, just export what you absolutely need. Usually its the skinned bones and the skinned mesh, so you can make a selection set and export selected. Its not essential but if the error annoys you its a quick fix.[/QUOTE]

Yeah, I’ve been doing that ever since I encountered a problem when I was still in school. Took me awhile to figure it out, but I eventually realized my problem after reading some posts on this forum. Very good to know though, thanks.

On another note, I’ve googled my problem and found that other people have had this same warning using FBX. The problem is that the initial default bind exports fine without the warning, however once you save and exit and then reopen the file, this warning shows up without fail.
I have not experienced this problem with my single mesh models before so I have an inkling it’s a multi-mesh problem. I haven’t worked on any other multi-mesh models before this one, so I think I’ll experiment with others and see what happens. I’ll reply with whatever I discover. Thanks again for the advice guys.

Edit: So I experimented with using a simple multi-mesh model and simple bind rig and when I saved and exited, then reopened the file I got the skin definition warning saying there is no bind pose.

“The plug-in has found the following skin definition problems :
Unable to find the bind pose for : / joint1 / joint3. No bind poses in the hierarchy containing the object will be exported.”

My suspicions seem to be true, FBX doesn’t like multi-mesh models that are not combined (I was successful in binding, animating, and exporting a multi-mesh combined model in the past). I’m not sure if there is a work around the uncombined model, but I will try to do some more experimenting. Perhaps one must bind the entire skeleton to each mesh individually?

8

I wrote this for rebuilding dagPoses (bind pose) that might help you.

I use it to clean multiple dagPoses, but it’s also useful if you need to just rebuild it for troubleshooting the kind of issues you seem to have.

Make sure you’re only exporting to FBX the stuff you want to see in game; i.e the skinned mesh and the joint hierarchy. A common issue is that people end up with all kinds of rubbish in their export which can be interpreted strangely on import to Unreal.
Also make sure that the skeleton and mesh are in the scene root (i.e not grouped or placed somewhere inside a hierachy) when you export them.

If you are still having issues getting it exported post a link to your Maya file and I can take a look for you. I’m building rigs for export to Unreal (both through ActorX and FBX) day-in day-out so should be able to track down the cause of your problems.

I must admit I’ve never heard of or experienced an issue with none-combined meshes through FBX, I very much doubt that’s a problem to be honest even if it looks at first glance like it might be. By detaching the separate meshes then rebinding with a combined one you are unknowingly rebuilding all kinds of things behind the scenes in Maya and it will be something there rather than the fact your mesh is combined.

Oh, also make sure your fbx plugins are up to date too.

Matt