If I have a POP Wrangle DOP with code:
@bla = smooth(@Frame, 24, 48);

I get a bla value of 1 until frame 48, where it then turns 0. It is not smoothly interpolating from 1 to 0 from frames 24 to 48.

The Help Docs say:
Unlike the Attrib Create SOP, this does not use local variables. Further, all backtick expressions and $F variables will be evaluated at frame 1, not the current time. Use Frame, Time, or TimeInc instead.

I was under the assumption when it says to use Frame, Time or TimeInc instead, that it would be able to do time-based calculations.

Any ideas here?

Thanks

And what would you suggest is the best way to set up time-based attributes on particles in DOPs? I was used to the Attribute POP, but that seems to be gone in DOPs.

yes, @Frame is correct, just arguments in the smooth function are in wrong order
try this
f@bla = smooth( 24, 48, @Frame);

Looks like the hscript smooth function is layed out differently than the VEX function. Thanks!

Yes, unfortunately VEX inherited the smooth() arguments from renderman to match RSL, but then they are backwards from what we have in HScript. I'm sure there is a parable about trying to serve two masters buried in here somewhere.

It ain't easy bein' pleasey!