I'm trying to figure out the AutoRig and how to modify it. I came across something that kind of baffles me and I see it a lot in the created animation rig. Maybe it's a simple thing but what does it mean:

A null references a non-existing SOP. For example the null ctrl_head has in its tx parameter ch(“../ctrl_head_tx”) whereby there is NO such SOP in the level.

Can anyone give me a heads up what this does? The doc for ch() says it Returns the value of a parameter. But in this case there is NO ctrl_head_tx SOP.

I see this a lot in the Autorig. For example something like Null1 would have the following in its tx: ch(“../Null1_tx”)

What does this do?

Thank you

This is the name of the parameter on top level (parent level). You can check it by hovering over your mouse on parameter.

“.” for current node.
“..” for parent node (one level up).


If you need to reference current node parameter then use ch(“./channelName”) or ch(“channelName”).
To reference parameter from one level up (parent node) use ch(“../channelName”).
To reference parameter from other node at same level use ch(“../nodeNade/channelName”).

A null references a non-existing SOP. For example the null ctrl_head has in its tx parameter ch(“../ctrl_head_tx”) whereby there is NO such SOP in the level.

It's looking one level up for “ctrl_head_tx” parameter.
If it is SOP in same level then it will be written as ch(“../ctrl_head_tx/channelName”) not ch(“../ctrl_head_tx”).

PradeepBarua

A null references a non-existing SOP. For example the null ctrl_head has in its tx parameter ch(“../ctrl_head_tx”) whereby there is NO such SOP in the level.

It's looking one level up for “ctrl_head_tx” parameter.
If it is SOP in same level then it will be written as ch(“../ctrl_head_tx/channelName”) not ch(“../ctrl_head_tx”).

Hi - whew - I finally get it… Sorry for being so dense

Many thanks for clearing it up… I didn't know that parameters could be addressed like that. I always thought if you went a level up you had to address the node first then the parameter. eg: ../../head_and_neck/ctrl_head_tx