As first assumption, there are geoA for amination object
and curveA for animation path.

I try Follow Path animation.
As you know,the position of geoA is decided by the parameter of　“Position”　in
Transform Tab.
Then how can I seek the world position from “Position” parameter?
I want to relate up vector of geoA and it's world position.

I very appriciate your reply.
Thank you.

You can use a chop network for this. use a object Chop to get the global transform. just a guess

martin

Thank you,Martin.
I really appreciate your quick and nice advice.
It 's very helpful for me.

takahiro

you can also try ‘vorigin’ expression function. You learn more about it in Help > Houdini Help and then going to the Expressions page (in the Reference column) and finding the link to the vorigin help page.

I was shown a way to approximate this using the object merge sop to evaluate a geometry in local space (as long as no transform happens afterwards it is equivalent to global space).

Thank you for your reply,Rafal.
origin(“”,“/obj/geoA”,TX) is a very useful expression.
I have misundestood it return 0 for follow path object!

Takahiro

Hello,Photex.
Thank you your idea of using object merge.It works well.
For more detail I searched all your posts with the keywords of “object merge”,
“global space”,“photex”! ,but can't find.
So please show your post for this topics.

Thank you.

Takahiro

Hey takahiro,

I didn't actually get this help from the forum so it wouldn't be there.

Here is a hip file that uses the method.

cheers!
_chip

Hi,Photex.
Thank you for your sample file.
It is a very helpful reference for me.
This method looks useful for many situation!
Thank you.

Takahiro

your storm animation and demo reel on your site is cool.

Thanks fujii

I'm glad I could help.