Vanishing Parent Strands for Particle Hair


For a reason I cannot find despite a couple hours digging in the file and comparing it to previous files with the same object, my Ann Darrow hair system wig has suddenly lost the ability to be edited. The parent strands and keys (other than the Root keys) have vanished and I cannot find a way to make them visible – and editable – again. Children strands show perfectly and the wig renders fine.

For a time even the Root keys were missing/invisible, but they suddenly appeared again for no reason I can figure. Once visible again they are now editable. Note the red arrow – full strands/keys display mode is enabled. If I switch to Tips mode I can edit the Tips but only the tips. Previous files with the same wig (only a slightly different edit) work fine as usual.

Did I inadvertently switch something off that I cannot now find to switch back on? I can Append a previous wig object but there are styling differences I would like to preserve.

Some more clues:

  1. If I select all the roots and use Hide, I can see the strands in the faded gray indicating hidden strands. When I Un-hide, the strands vanish.

  2. If I append the same wig object from another file where, in another instance of Blender, I can see the strands in Particle Edit mode, I can no longer see the strands of the appended object as well. This indicates it is not a mesh/particle system/object issue, but rather something specific to this particular Blender file, like a UI toggle I cannot find, though I have tried virtually every toggle even remotely connected to the hair system object, and a few that aren’t.

So I cannot correct for this by appending, and I see no alternative but trying to append the entire scene file into a new instance of Blender, where, hopefully, the mysterious “turn off Parent Strands” toggle (or bug) is no longer in effect. Unless one of you kind people can clue me in.

EDIT: Appending the entire Scene to a new Blender instance does not fix this. This is getting depressing.

I’ve seen blender do funny things when trying to particle edit a system that has been baked for hair dynamics. If you previously baked it have you freed the bake? or gone back to frame 1 to edit. Other than that not sure, can you post the blend?

Also worth a shot, save the file into a different directory, sometimes blender gets greedy with stale caches.

p.s. Great work on the muscle system!

Thanks for the compliment, Photox. Problem with the wig is, I wanted to bake Hair Dynamics for a test animation, and that’s why I was entering Particle Edit, to do the strand weights. So there was no HD or cache to consider when the problem showed itself.

I am currently baking the HD “blind” so to speak, and everything is working as it should except for the darn invisible strands. Perhaps whatever weighting I may have applied in the past persists and will suffice. But I won’t be able to re-style the hair at all.

More oddness: I have a second wig stored on a hidden layer, and when I bring that one into Particle Edit, I see a few parent strands but not nearly all of them. I would think that indicates a corrupted file if not for the fact that appending the entire Scene into a fresh instance of Blender does not fix the problem.

I didn’t find a solution but there are almost always workarounds. In this case I was able to append the problem wig into a new Blender file and edit the strand weights there, then append it back into the original file for baking & animation testing. And all is (pretty much) good now, doing the final previz as I type & will post it soon.

I will also strip the problem .blend down to barest essentials & submit it as a bug report since there don’t seem to be any solutions in the normal Blender usage context.

It may be destructive but did you try to w-rekey to say 5 or so? Also alt-H. I had this issue and never did find a good solution other than the rekey. It would be good to know how it happened.

Yes, Re-Key is usually destructive and rarely helpful in my experience, but TY for the suggestion. The workaround is a bit clumsy but very safe. I’m rendering now with the wig as edited in a separate file & appended, and it’s working super.

Odd thing about using Hide – if I hide the “invisible” strands I can see them (but not edit them, as they are Hidden), but when I un-Hide them (Alt+H) they vanish again. <sigh>

Every once in a while, especially with sims, there is nothing to be done except appending. :no:

Noted in my “Big Book of Blender Bylaws.” :wink: