Double Transform Problem

[jsahn]

hello,
i have a double transform problem. when i move a model (a bird, in my case), the paint effects (feathers on the bird) does not move with the model.

deleting the history solves the problem, but it also deletes the 'time' attribute and loses the ability to animate using the paint fx dynamic. in other words, i can't use the 'turbulance' attribute.

does anybody know how to get around this issue?

thanks as always,

h.

[jsahn]

just want to add more info...
i noticed that before my geometry (skin) is bound to the skeleton, the paint fx has no problem. it does follow the geometry. would it be possible to delete certain parts of the history rather than entire history?

thanks,

h.

[duncanbrinsmead]

I'm guessing that you did pfx to poly on the feathers and had them selected when you did the bind skin. This would cause the double transform problem. Just select only the body, not the feathers when performing the bind skin. (I tested it, and it worked OK for me)

Duncan

[jsahn]

Duncan,
thanks for helping me out.

i just found out that the double transformation happened even before it was rigged.
However, when i first applied paintFx feather, it worked fine. I don't know what i did wrong along the way. i tried applying new paintFx feathers on the same mesh, and it did work fine. i have control curves to control the feather placement, but i don't think that's causing the problem.

do you have any idea?

again, thanks a lot!

h.

[duncanbrinsmead]

Another problem I've seen is people accidentally parenting the strokes to the object, which also causes double transforms. The stroke path curve position is driven by the object position and the strokes should have identity transforms to match the path curve positions.

There was a bug in one release where transforming the stroke in the shaded mode displayed a double transform( did not appear in wireframe draws or renders however ). You would see this problem if, for example, you had parented the strokes to a surface, having created the strokes with "attach brush to curves", instead of painting directly on the surface. However that was just a display bug. Note also that "attach brush to curves" now allows you to select a surface object to attach the curves to(based on the nearest points to the curves).

Duncan

[jsahn]

Duncan,
the strokes are not parented to the object, and i don't think it's the display bug issue. when i render it, it's still not in the right place.

i did trouble shooting all day and can't still find why it's doing that... i'm think about doing it all over again. should i apply the paintFx after i rig it? are there any precautions that i should pay attention to when using paintFx?

but thanks a lot...really.

h.

[duncanbrinsmead]

It still sounds to me as if your bind skin included the feathers or parented them somehow. If you delete the stroke history, then the feathers should NOT move with the surface if the setup is correct. The fact that it does means that the feathers are somehow bound to the surface in addition to the way the path curve for the stroke is attached to the surface.

If you recreate it then create the strokes last, because some as yet unidentified thing in your workflow is likely applying a tranform or deformation to the output of the strokes.

Duncan

[jsahn]

Duncan,
actually when i delete the history. it does work. however, it also deletes the 'time' attribute on the paintFx, which i don't want to lose for animation. i got rid of the skeleton, but it still has the double transformation problem. ugh.

thanks for the tip though.

h.