Skin wrap modifier "Convert to skin" causes mesh to distort horribly.... what gives?

RezNik

Ok, Im not an animator.... Any hints or tips about why my mesh freaks out when I convert to skin? It seems to work fine with the bone based rig before conversion.

Farfarer

Is it because it's not in the bind pose?

JacqueChoi

haha.

It's a max bug.


You fix it by going to 0 Frame, then un-checking, and re-checking 'Always Deform'.

Noors

Max always has a little joke to cheer you up.

RezNik

@Farfarer I've done this before without placing the mesh/rig into a bind pose. So Im thinking thats not the problem

@JacqueChoi Where is this awesome check box? I'm using max 2010 and its now where in the rollout

Noors

It's in the skin modifier, under Advanced Parameters.
Beware to set a frame where your "unskinned" mesh is aligned with the rig (usually 0).

Mark Dygert

Did you select all of your bones, go to the main menu/animation and set the skin pose before you skinwrapped? That "helps" but won't solve the problem if frame 0 has been changed since binding the mesh to the skeleton.

The skin pose for the bones, should match your bind pose, which should match your skinwrapping mesh. Skinwrapping to a mesh that doesn't share these same properties or has been moved or is animating is a dicey operation. It will almost always fubar the skinwrap if you do your skinning on frame 0 and then later change your skeletons position/orientation on that frame.

It will seem to continue working because it took a snapshot and is retaining it within skin, but once you edit that frame it becomes a ghost, not everything will see it and interact with it appropriately. Setting the skin pose will help bolster its presence but really with custom rigs you should always have a bind pose frame.

Other rigs like CAT and Biped get around this by storing it separately in a different mode, figure mode and setup mode. So with CAT and Biped you can do whatever you want with frame 0, nothing important is stored there. With custom rigs unless they are very advanced, just don't handle it the same.

(you can hold atl and right click to set/assume skin pose also)

Randy2575

I know this is three years old, but I'm having the same issues with Max 2014, only it seems to be getting progressively worse.  The first few times I applied the skin wrap to some boots, everything worked.  Then, the bottom part of the left boot started to appear flattened out.  Now it's to the point where both boots are completely flat, like they've been run over by a steam roller.  The part I really don't get is the progressive nature of this bugaboo.  Help!

Zhalktis

The issue isn't Skin_Wrap modifier, it's how the newly created Skin modifier interprets the "zero pose" to count deformations from. Make sure you set the "ref frame" under "advanced parameters" in Skin modifier to a frame that has your bones in zero pose (matching your model), then toggle the "always deform" checkbox to reset skin modifier.

The progressive nature of your problem may be because you're generating additional skin modifiers without disabling/deleting the old ones. Skin modifiers will act additively.

Mark Dygert

^ Yep ^