Bones animate but not skin

[Zero713]

Hi. I was working with animation exportation from 3ds max to udk. And i did the animations, exported the mesh and the animations, imported them into udk and all. But when i import the psk animations, nothing happens when i play the animations. I checked the bones, and the bones are moving correctly, but not the skeletonal mesh. What am i doing wrong?! This has been a problem for a while.

[vimpel_zocom]

Hm... this is strange...

[Graylord]

Just to get it out of the way. Have you actually skinned the mesh?

[Hitpawz]

Do you have a root bone?

[Bofur77]

Have you Anim Rotation only activatet?? I think that is the problem .. just deactivat it

You find it under Properties - Animset

sry for my bad english

[Zero713]

Sorry for the late responce. Yes, the model is rigged, boned, skinned, animated and all seeing perfectly in 3ds max. Yes, I have a rootbone at 0,0,0 and I disabled the Anim Rotation only, still nothing. This has been happening for a while and it has really been crippling my work. Please help. >.<

[Hitpawz]

This happened to me before but I can't remember what fixed the issue. I had a helicopter with spinning blades and the bones were spinning but the mesh was not following. It all was right in max. I believe in the end, I reskinned the mesh to the bones but I might of recreated the skeleton.

I know that sounds harsh and depending on the project can mean months of work...but if you want to see if this might even help, try weighting a copy of the model to just two bones that bend it in half and export that mesh with a simple animation and see if that can actually work.

If you do just have to redo the skin modifier, save the envelope weights (located down on the skin modifier properties window under "Advanced Options" and the big SAVE button) and then delete the skin modifier, add a new one, add the same bones and load the envelopes from the file you saved out. Just hit "Match By Name" when the window comes up and check that the incoming and target bones are aligned to the same names. This may or may not solve the problem.

If you have to create a new skeleton, the fastest way is to draw out the rough heirarhcy of the new skeleton to match the old, activate "bone edit mode" found under animation-bone tools and align the new bones to the old skeleton. You can align by position and orientation so it goes by pretty quickly. You can then load the envelope weights using the same method.

[mightyenigma]

It may be important to note that PSK files contain no animation, only your mesh, refpose, and maybe some other geometry stuff, and maybe the rig(not sure).

PSA files, on the other hand, contain just animation, (but I think they need to match up with the PSK so they use the right skin?).

So you have to import your PSK to have your model and rig, and then you need to import your PSA to get any animation sequences.

[xGallox]

I'm having the same issue, any response?

[geodav]

skinning problem, always is, if the bones move in the udk editor then it's a skinning problem in your 3d program, even if it looks alright. been there done that and cursed myself for being stupid

[Kelt'ar]

How bout a vid?

[tiny_wah]

As I am new to working with bones, Im not sure if my issue is the same or related to yours but looks like you may have worked it all out. My problem is when I put key frames on the time line to move the bones around to test the mesh, it does not deform, like as if the skin modifier wasnt applied. I made sure the light bulb white (turned on). For some resaon it worked fine while I was editing the weights and it deformed the way I liked it on 3DS Max Design 2012. Then all of a sudden it stopped working, maybe I have clicked on some short cut keys without myself knowing when max had focused. Restarting Max / Rebooting Windows doesan't clear the problem.

Possible Solution A:
1. LMB click on the mesh that is not deforming
2. In the modifier List window RMB on Skin or Envelope
3. Check with a tick on Preserved Customs Attributes
4. RMB again and now make a tick selection is next to "On" (above "Off in Viewport")
5. The Mesh should now deform witht the bone(s)

Possible Solution B:
6. If the above fails, you may have made some modifications to the model (for example added more geometry or welded elements together), In clicking on the editable poly/mesh, there should be a dialogue Warning that pops up saying this:

"A modifier exisits in the stack that depends on topology. Change parametrers may have undesireable effects. The dependant modifier is SKin...." blah blah blah...

Press the button Hold/Yes. This has resolved my problem and animation has returned (but I had to fix a few corrupted skin weight vertexes). If you choose NO, you will find the bones will fail to animate the geometry. If the Hold/Yes button doent work, then you may have to delete the skin modifier and start again (I know this is a pain but any one else has another solution, your welcome to add your input).

Possible Solution C:
7. If step 6 continues not to work after reskinning, then you need to Reset Xform and then collapsing the modifier stack. WARNING you can not undo this step so save your project first befoe collapsing. This is a drastic step, if you have no idea what your doing in this step, I recommend to Google this step first and check with the Max's help menu before committing yourselt to it, so to obtian an understanding what the consequences are. Press on the hammer icon located above the modifer list roll out (Utilities button if you hovering over the icon), there you find Collapse and Reset XForm buttons. You may just only need to Reset XForm. As I am no expert in the inner workings of 3DS Max, this step may require an expert opion as I can be misleading you. Use it as a last resort if there is no other help.

Additional information:
From my experiance when I imported the model, I had to scale it down. I know scaling is evil and casue huge problem if done ununiformly (and reveals as sudden stretching or collpasing in size when animated), but I had to scale it in world space as scaling in sub object mode results in the indivdual object elements in shifting making the model fall apart (as origianl anchor point(s) was moved).

Pressing Rest XForm had an adverse effect in reverting the model back to the origianl size at import, not a desiirable solution. That is why Collapsing the Modifier stack was required to work around this problem.

Though your model maybe exactly how you like to look, but you cant go back to fix any issues (for example you missed welding a couple of vertices - reveal by animating), so saving a copy is VERY IMPORTANT, this gives you the opportunity in returning to scene to make edits or changes with all the modifiers present. To get started, search in Google for this video: 3DS Max - reset Xform, Monday Movie #29: Reset XForms.

Other related video - Lynda.com: 3D Max 2011 Essential Training\15 Hierarchies\1506 Preventing problems with scale. FYI: Manditory - always Reset Xform prior to rigging. (Subscription required.)

[Braindrain85]

If you are exporting via e.g. fbx, make sure to check exporting animations, skins, and so on.... (exporter settings)