Using 'Fit XYZ Character' Dials On A Prop - Poser 9 Parenting Problem

This helmet prop loads in the correct position to fit Michael 3. I've added dials to fit the helmet to various other figures - the dials simply adjust the helmet's position, orientation and scale using ERC (or master/slave, or dependent parameters, whatever you like to call it).

Two screenshots below using Poser 9 and Aiko 3.

Fine so far - the helmet's in the correct position with y translate driven to -0.068 and z translate driven to -0.019

Now I'd expected the helmet to stay exactly where it was, i.e. nicely positioned on Aiko's head, not disappear half-way down her throat!
So I took a closer look and noticed that the Y translate and Z translate values appear to have been applied a second time - y translate is now 2x(-0.068) and z translate is 2x(-0.019).

If (in step 1 above) I manually dial in the values y translate = -0.068 and z translate = -0.019 instead of using the FitA3 dial the parenting works fine.

So can anybody explain why this is happening?

(P.S. The fitting dials work fine in DAZ Studio 3 and 4.5)

Did you try parenting first before moving the dial?

Laurie

If you parent the prop first, and then set the fitting dial, it seems to work fine. (But being parented to the head means that the XYZ translations of the helmet are along the head's local axes. So unless those axes are perfectly aligned with the world axes the helmet ends up in a slightly different position. For most zeroed figures it's not a big difference, so not really a problem. But I set everything up using world axes, so I'd need to recheck for each of the 40-odd figures I'm trying to support...still, keeps me out of trouble!)

I think I really want to understand why the effect I mentioned is occurring - there may be a logical reason, but it seems like a bug to me (it's also the same in Poser 6).

P.S. I think I'll be using a script-based solution anyway (already tested in Poser 9) so this is mostly intellectual curiosity...

Well, I know with hair that have had fit poses, they are always parented first (on loading) and then the dials for the fixes are applied :).

Laurie

Quote - 2) Parent the helmet to Aiko's head.

You are making life very hard for yourself. A hat should be a smart prop, so that it automatically parents to the head of the selected figure when it is loaded. Making it a smart prop should cure your problems, though you may need to redo the ERC for fitting it to different figures.

As to why it is happening, I'm not sure, but it might be down to a P9/PP2012 bug, they changed how the parenting worked in P9, and it broke things, but I thought that had been fixed in the latest service release. If the figue, or parts of it are scaled, that could also cause the prop to change location when parented.

Laurie/Les: Of course! I was avoiding smart-propping because it was specific to a single figure. But with these ERC dials the fitting adjustments can be made after it's loaded and parented. Yes, I'll have to recalculate the values for each figure, but that's a small punishment - the equivalent of writing out 100 times "I must remember to parent first by smartpropping, before applying the ERC fitting dials"...

P.S. my approach of making the fitting adjustments in world space before parenting is based on my 'Smart+' prop script-based approach*. That was originally designed for hand-held props where it was much, much easier to make fitting adjustments in world-space and then parent, than to parent and adjust in the hand's local axis system.

I know that the script worked in Poser 8, but I'm not sure whether I checked it in Poser 9...

*My S.E.Asian sword and shield freebies both use this 'Smart+' prop scripted approach.

Python scripts can be very usefull, but a very big downside is that a py script that works in one Poser version may not work in some different Poser version. For that reason, where possible I prefer to use Poser script (eg a pz2 file).

Just checked and my old script seems to work fine in Poser 9 too (already proven in P6 and P8).

So regarding the original query (i.e. is it a Poser 9 bug), it seems I can completely side-step the issue either by using a smart-prop with fitting dials, or by using my script.

Quote - Python scripts can be very usefull, but a very big downside is that a py script that works in one Poser version may not work in some different Poser version. For that reason, where possible I prefer to use Poser script (eg a pz2 file).

Point taken Les. I'll do it both ways - script and smartprop.