[Sidefx-houdini-list] local variables in VOP SOPs

Andrew D Lyons tstexture at gmail.com
Tue Dec 18 15:24:39 EST 2007


It's been a while since I've wanted to put an expression in a Vex OP,
but from memory it was using an OP that hadn't exposed the
import_attribute VOP attr name string as a parm. As a result I wanted
to use opinput to pull in an attr from the input SOP and couldn't.
Maybe better OP creation would have provided another workaround...

Cheers



On 18/12/2007, Ivan DeWolf <ivan at martian-labs.com> wrote:
>
> also, why would you want to? if you're asking Houdini to solve some complex
> expression in an argument field of a custom VEX SOP, doesn't it make more sense
> to do that computation in your VEX code? (or VOP net, whatever) you have access
> to the same point attributes, and you're already creating code (or nets)...
>
> having said that, however, VEX (and VOPs) seems unable to read int point
> attributes, and 2-dimensional float point attributes. ID is an int point
> attrib, and life is a 2-d float point attrib.... so I usually precede my VEX
> SOP with a point SOP and set $CR to $LIFE and $CG to $ID and access Cd in the
> SOP, or something similar.... a minor hassle, but worth noting... (unless this
> has changed in H9.?.???)
>
>
> Quoting Peter Bowmar <pbowmar at gmail.com>:
>
> > No Houdini locals work in VEX/VOP nodes. You have to put it into the
> > VOPnet itself as a Parameter VOP to get it to import. This is how VEX
> > works. It's for speed, as local variables are relatively slow to
> > calculate whereas the pure VEX is very fast.
> >
> > Cheers,
> >
> > Peter B
> >
> > On 18/12/2007, Andrew D Lyons <tstexture at gmail.com> wrote:
> > > Yeh - I hear you. Some Houdini locals work, and some don't from
> > > memory. I'm surprised $LIFE doesn't.
> > >
> > > Good $localVar and expression support in Vex OP UI parameters would be
> > > the icing on the vex OP cake IMHO. Often it's necessary to wrap vex
> > > OPs in a HDA subnet that handles all the attribCreate nonsense for
> > > artists, but then you end up with 2 ops for every purpose in your
> > > menus. One that does the raw vex number crunching and one that has
> > > high level bells and whistles for users. Often they are named in a
> > > similar way, and then people have to remember which OP is the decoy
> > > and which is the money (depending on how they look at it.)
> > >
> > > This brings me to another long-standing RFE - the ability to load a
> > > hda - and have it accessible - but yet not appear as clutter in your
> > > OPmenus. I thought that was going to be part of H9 - but I'm yet to
> > > see it. Anyone know what happened to that one?
> > >
> > > Cheers
> > >
> > >
> > >
> > > On 17/12/2007, Jerry Corda-Stanley <jerry at intelligentcreatures.com> wrote:
> > > > Well I created the VOP SOP in H9, and wanted to stick $LIFE in the
> > parameter
> > > > field of the VOP I created to change the colour.
> > > > I was trying to keep it neat with out messing about with attribute
> > creates
> > > > and so on.
> > > >
> > > >
> > > > ----- "Andrew D Lyons" <tstexture at gmail.com> wrote:
> > > > > In the SOP parameters or in the VOPnet itself?
> > > > >
> > > > > Traditionally there have been problems with putting complex
> > > > > expressions in the parms of a VEX OP. Often you have to override VEX
> > > > > parms by creating an attribute of the same name and type with an
> > > > > attribCreate SOP further up the chain. If you have a parameter VOP of
> > > > > the same name you generally pass things in that way.
> > > > >
> > > > > Cheers
> > > > >
> > > > > On 17/12/2007, Jerry Corda-Stanley <jerry at intelligentcreatures.com>
> > > > > wrote:
> > > > > > How do I get local varaibles such as $ID and $LIFE to be recognised
> > > > > in a VOP SOP?
> > > > > > I put together a SOP to futz around with stuff and it's complaining
> > > > > that the variables
> > > > > > are undefined. So how do I define them?
> > > > > > _______________________________________________
> > > > > > Sidefx-houdini-list mailing list
> > > > > > Sidefx-houdini-list at sidefx.com
> > > > > > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
> > > > > >
> > > > >
> > > > >
> > > > > --
> > > > > =======================================
> > > > > Andrew D Lyons | Digital Artist | http://www.tstex.com
> > > > > =======================================
> > > > > _______________________________________________
> > > > > Sidefx-houdini-list mailing list
> > > > > Sidefx-houdini-list at sidefx.com
> > > > > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
> > > >
> > > > _______________________________________________
> > > > Sidefx-houdini-list mailing list
> > > > Sidefx-houdini-list at sidefx.com
> > > > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
> > > >
> > >
> > >
> > > --
> > > =======================================
> > > Andrew D Lyons | Digital Artist | http://www.tstex.com
> > > =======================================
> > > _______________________________________________
> > > Sidefx-houdini-list mailing list
> > > Sidefx-houdini-list at sidefx.com
> > > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
> > >
> > _______________________________________________
> > Sidefx-houdini-list mailing list
> > Sidefx-houdini-list at sidefx.com
> > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
> >
>
>
> -Ivan
>
> ---------------------------------------------------------
> "Perfection is achieved when nothing else can be removed"
> -Yvon Chouinard
> _______________________________________________
> Sidefx-houdini-list mailing list
> Sidefx-houdini-list at sidefx.com
> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>


-- 
=======================================
Andrew D Lyons | Digital Artist | http://www.tstex.com
=======================================



More information about the Sidefx-houdini-list mailing list