Something strange happened. My clothing and other textures continue to apply properly using the MAT poses, but not for hair. Nothing happens when I double-click or drag-drop the pose file. This is the case no matter which HR2 I use, and it happens in both PP2010 and PP2012.

I hadn't tried to change hair colors in awhile, so I can't be certain when this started. I did reinstall PP2012 recently, and applied SR1, but I can't change hair colors in PP2010 either. Why would the rest of my MAT poses work, but not for hair? All my textures are in the same runtime. PP2010 and PP2012 are in different locations, but as I said I can't change hair color in either of them.

I am assuming that the MAT Poses match the hair props they are for.  And I am also assuming that the textures are not material files.  What is going on in the Material Room?  Are there changes to the nodes?  And are we referring to the Preview window or actual renders?

Yes to your assumptions. These are MAT poses that I have used many times before, and they include every hair MAT in my collection. Nothing is happening in the Material Room. Nothing is applied by the pose. I even tried a new hair piece I bought, that loads with no textures at all. The MAT pose does nothing, and the Mat Room shows that nothing at all was applied to the default white texture.

I'll bet you have the hair parented to something other than the character's head or neck. Like say, a shirt or a genital figure. Parenting to odd things can result in the effects you describe. (As me how I know!)

Quote - I'll bet you have the hair parented to something other than the character's head or neck. Like say, a shirt or a genital figure. Parenting to odd things can result in the effects you describe. (As me how I know!)

I was about to say, "Nope. I'm talking about the hair being the only object in the scene." Then I thought, maybe that's the problem. And indeed it was. I never knew before that hair MUST be parented to a figure before the MAT will work. I guess I'd never tried it before on hair that was alone in the scene.

Thank you for saying the thing that got me thinking in the right direction. And sorry for wasting a thread, but maybe someone else will read this and learn.

That is why, currently, there is a push to get away from MATPose and delegating the Material Room as the preferred place to add textures to figures and objects.  AS Basicwiz stated, props will not accept textures from MATPose files unless they are parented to a figure. 

Quote - That is why, currently, there is a push to get away from MATPose and delegating the Material Room as the preferred place to add textures to figures and objects.  AS Basicwiz stated, props will not accept textures from MATPose files unless they are parented to a figure. 

That would a really good move: would save me from having to convert a whole bunch of mc6s into pz2, a HUGE PITA.

Weren't MAT pose files some sort of kludge? Can't remember the history, but yeah: materials in the material room. Fantastic! Progressive. Innovative. And a whole bunch of other really good things.

Hborre has it.  hr2 files - which are actually pp2 files - won't take MATs unless parented to a figure.

Material Collections applied from the Material Room have no such restrictions. 

Can that restriction be removed by changing or removing a line in the pz2 file? (Like mat files can be made into pose files by changing "mtlCollection" to "figure") 

I dunno.  I guess you could change the prop into a character but what's the point?

A  pz2 MAT is an old, unloved and never officially supported format.  It started life as a hack and grew from there.  Better to stick with MC6, IMO.

Quote - Better to stick with MC6, IMO.

After my experience I won't argue. Unfortunately most vendors don't agree.