[Sidefx-houdini-list] python expressions... how we doing?

Rangi Sutton rangi at kanuka.com.au
Wed Jan 23 03:42:36 EST 2008

Peter Bowmar wrote:
> Hey Rangi,
> First off, can't help you :)
> Second, I've been getting into Python for scripting stuff, like the
> Hython shell, and the cookbook is great for that. Just the solid
> string manipulation and the "unexpandedString()" function make it all
> worthwhile :)
> However, from what I've seen, the Python use in Expressions isn't as
> great, because you have to type WAY too much stuff and also because
> Python is a lot slower than custom Hscript expressions.
> We're continuing to use Hscript expressions (custom or otherwise)
> while moving to Python to replace scripting in Hscript. I don't see
> that changing anytime soon, mainly due to speed issues as very often a
> custom expression runs loops, or gets evaluated many times per frame
> on multiple operators.
> However, to be fair, because of the lack of Cookbook examples, I
> haven't done extensive testing so this might be better in 9.1 but I
> don't have time to learn it without the examples ;)
Thanks for the insight Peter. Seems like uniformly using python for 
expressions is an ideal, but the speed hit constructing the expressions, 
and the speed hit evaluating them will keep 'em out of our hips for a while.

Anyone from sidefx care to comment on this issue? The manual suggests it 
is a replacement, is it too early to swallow that pill?


More information about the Sidefx-houdini-list mailing list