How can we reference a channel in a VEXpression ?

Docs say: In the snippet, you can read/write the value of a parameter on the node using parameter_id.

So I created a spare float called b.

Now in a wrangle I typed:

@get_b = b_b;

It throws error. I tried a bunch of other ways too with no luck.

Any help?

the referencing by purely typing name works only for existing parameters that are bound to the variables inside assets containing VEXpression field

to get the value of any spare parm you'd need to use ch() function or better corresponding expression to parm type (chf() for float parm, chv() for vector, chi() for int, etc.)

so in Wrangle it would be
f@get_b = chf(“b”);

Darn it! I could've sworn that was the first thing I tried.

Thanks !

Hi, in Houdini 180.308 right now. Just a quick question about referencing spare inputs:
when I type chf(“spare_input0”), everything works fine, but chf(-1) throws an error. Am I using the -1 shortcut wrong, or is this a bug?

Cheers,
Ivan

It appears your not using the full syntax required for chf when using op_id.

http://www.sidefx.com/docs/houdini/vex/functions/chf.html [www.sidefx.com]

I don't know, never used that variant and whether or not it's ok to use it like you have tried.