I wrote an HScript function like this:

prim(“../some_node”, 0, “P”, 2")

As I wrote it I realized that it was wrong, because my prims have no P attributes. However. it worked!

I think there is a hidden P attribute that is the center point of the prim. Is that right?

Are there any other hidden attributes?

Hi, Patrick,

I just tried this and found that actually it works even if you replace the “P” with whatever string and there's no error message.

I'm not sure if “P” is a hidden prim attrib. I guess the “prim” hscript command will treat whatever prim attrib that is not embedded in the current node as unrecognizable and return a zero value.

anyway, it'll be more appropriate to let the houdini expert to answer this question.

Ji

Sorry - I just read the help for the prim function
http://www.sidefx.com/docs/houdini11.0/expressions/prim [sidefx.com]

It says:
When given the “P” or “Pw” attribute, returns the centroid of the primitive.

So there is my answer. However, it also seems to work with “N”. See attached file (V11).