[Sidefx-houdini-list] H9 : wire glue constraint pb

guillaume laforge guillaume.laforge.3d at gmail.com
Thu Oct 4 05:40:36 EDT 2007


Forget my post, problem solved !

If someone is interested, here is how to transfer animation from a skin
deformation if you can't use a Copy SOP ( as the guides are not create in
houdini).

Add a Primitive SOP after your guides. Put the deformed skin geometry in the
Template input and turn on "Do Transform". Set the pivot parameters to the
position of your goal points on the guides with an expression like this  :
point( "../Your Guide", $PR, 'P', 0).

Cheers

Guillaume


On 10/3/07, guillaume laforge <guillaume.laforge.3d at gmail.com> wrote:
>
> Thanks Derrick,
>
> It works fine for my simple scene and I (slowly) understand how it works
> in 9 now :-).
>
> What I'm trying to do is to use some guides create with Softimage xsi hair
> tools.
> In Houdini 8, it is easy to "glue constraint" the roots of the imported
> xsi guide to the deformed skin but I don't know how to do the same thing in
> 9 for the moment :-/.
>
> Here is a sample file showing my problem :
> http://www.vol2nuit.fr/xsi_guide_to_h9_wire.rar
>
> How can I achieve a simple dynamic simulation of those guides in Houdini 9
> ?
>
> Cheers.
>
> Guillaume Laforge
>
>
>
>
> On 10/3/07, Derrick Moser <derrick at sidefx.com> wrote:
> >
> > Guillaume,
> >
> > The parameters in the wireglueconstraint1 node just need some
> > modifications.
> > 1) correct the constrained object's name by choosing "wire_hair" from
> > the Constrained Object's menu
> > 2) turn off "Constrain To Animation"
> > 3) choose the "rbd_skin" in the Goal Object's menu
> > 4) update "Goal Point" to the point you wish to constrain to ("15" for
> > the attached example)
> >
> > Some other things you may wish to consider:
> >
> > The "Goal Point" does not need to be specified (use -1) if the RBD
> > object's animation is at the object level (instead of animating in SOPs)
> > because DOPs will consider the object moving as a whole instead of
> > deforming.  This also means wires can be constrained to arbitrary
> > locations on the RBD object instead of being limited to the points of
> > the RBD object.
> >
> > If you want to use deforming geometry for the RBD object, consider
> > transferring the motion to sop_hair (maybe through a Copy SOP) and
> > turning on "Use Deforming Geometry" in the wire object and "Constrain To
> > Animation" in the wire glue constraint.  In this case, the RBD object is
> > no longer required in the DOP network but you may wish to keep it around
> >
> > for a collision object.
> >
> > Cheers,
> > Derrick
> >
> > guillaume laforge wrote:
> > > Hi,
> > >
> > > It is my first try with Houdini 9 wires and I can't figure how to
> > constrain
> > > some curves roots to a geometry.
> > >
> > > In H8 I used the goalpoint attribute to identify the points to
> > constrain but
> > > in H9 it doesn't work. The help sample files show the use of a "roots"
> > group
> > > to
> > > identify those points but I can't make it works in this simple setup :
> >
> > > http://www.vol2nuit.fr/wire_glue_constraint.hip
> > >
> > > Thanks for any help !
> > >
> > > Cheers
> > >
> > >
> >
> > _______________________________________________
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> > Sidefx-houdini-list at sidefx.com
> > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
> >
>
>
>
> --
> Guillaume Laforge




-- 
Guillaume Laforge



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