[Sidefx-houdini-list] How to control RigidBody instances

Olivier Jeannel facialdeluxe at gmail.com
Thu Nov 30 06:19:37 EST 2017


I think it is working here, check the file :)

As long as the target points (input2 of the CopySOP) have "orient"
attributes, the copySOP should use it to orient the copy.

I made a little tut about "orient" and 3x3matrix.
You can see 2 methods for orienting with attributes before the copySOP and
after the copySOP
https://vimeo.com/207626604


2017-11-30 10:09 GMT+01:00 Thomas Volkmann <listmail.3d at gmail.com>:

> Alright...still havent figured it out.
>
> So if we take your example as a basis, I want to create a new Geometry
> object, merge in your cube animation and replace the cubes with something
> else.
>
> My approach would be:
> MergeObject(Cubeanim)->add(deleteGeo)->copytopoints(input2)   and
> sphere->(copytopoints(input1)
> Works fine, except I don't get the rotations... :(
>
>
> On Thu, Nov 30, 2017 at 9:15 AM Thomas Volkmann <listmail.3d at gmail.com>
> wrote:
>
> > Thanks a ton Olivier! Some initial confusion and instant enlightenment
> > going on here :)
> > You gotta love the fact that you can just look at the generated VEX code
> > from your attribute-vop.
> > Extractxform translates to cracktransform... this is probably what I am
> > looking for.
> > Great seeing the randomize-value-by-range nodes! I think I did these on
> my
> > last project, too. And a randomize-vector-by-cone. Wasn't there a thread
> > somewhere with people building ICE compounds in Houdini? I'll have to
> look
> > for it again.
> >
> > On Wed, Nov 29, 2017 at 10:40 PM Olivier Jeannel <facialdeluxe at gmail.com
> >
> > wrote:
> >
> >> Here is the setup, I added some comments.
> >> https://drive.google.com/open?id=1swFzpbJ34b4mT9cJxneFa6gZuDZZmx20
> >>
> >> It shows 2 methods
> >> 1/ pointVOP creates classic P and Orient and then turn these into
> >> IntrinsicTransform
> >> 2/ pure VOP Intrinsic
> >>
> >> I often use these setups,  (once get used to) they are very similar to
> how
> >> we animated stuff in ice.
> >>
> >>
> >>
> >>
> >> 2017-11-29 21:16 GMT+01:00 Olivier Jeannel <facialdeluxe at gmail.com>:
> >>
> >> > I have a setup in vop to intrinsic transform. I can share it if you
> want
> >> > to have a look.
> >> >
> >> > 2017-11-29 16:25 GMT+01:00 Thomas Volkmann <listmail.3d at gmail.com>:
> >> >
> >> >> Thanks Olivier, I think I stumbled upon that video during a former
> >> Houdini
> >> >> project. Definitely makes the SI to Houdini transition easier...
> >> >> But now to the latest problem....
> >> >> I want to replace the rigidbodies with some other object after the
> >> >> simulation.
> >> >> So I merge the sim-object, use "add" to delete the geo and just keep
> >> the
> >> >> points (very intuitive) and then I want to use a "copy to points"
> node.
> >> >> By default everything goes haywire, but when I disable "transform
> using
> >> >> point orientations" hte objects end up in the right positions but
> have
> >> a
> >> >> static rotation.
> >> >> I guess I have to get the intrinsic transforms and apply them to the
> >> point
> >> >> orientation (or similar) before the copy, but I really can't figure
> it
> >> out
> >> >> atm....
> >> >> Any ideas?
> >> >>
> >> >> On Wed, Nov 29, 2017 at 10:44 AM Olivier Jeannel <
> >> facialdeluxe at gmail.com>
> >> >> wrote:
> >> >>
> >> >> > If triggers for sims is you're thing, I enjoyed this tut :
> >> >> >
> >> >> > http://shortandsweet3d.blogspot.fr/2017/01/xsi-to-houdini-4-
> >> >> from-states-to-streams.html
> >> >> > If you're in pop or dop and want to play it like in ice State
> >> >> > Machine, Mikael Pettersén nailed it.
> >> >> >
> >> >> > 2017-11-29 10:35 GMT+01:00 Olivier Jeannel <facialdeluxe at gmail.com
> >:
> >> >> >
> >> >> > > You can use "Attribute Create" if you're in sop.
> >> >> > > Otherwise in Vop, "Bind Export".
> >> >> > > Checking with the Geometry Spreadsheet to insure every attributes
> >> are
> >> >> > > there, or hit "x" and click a node to create a temporary
> >> vizualizer.
> >> >> > >
> >> >> > > 2017-11-29 9:29 GMT+01:00 Thomas Volkmann <listmail.3d at gmail.com
> >:
> >> >> > >
> >> >> > >> Yep, I found merging and then referencing the input to be the
> most
> >> >> > >> straight
> >> >> > >> forward for me. I had the intention to do as much as I can in
> >> code,
> >> >> but
> >> >> > >> obviously my skills are still limited :)
> >> >> > >> But on another note:
> >> >> > >> Where would you store some global variables that should be
> >> >> referenced by
> >> >> > >> some other objects (eg. a frame number that should act as a
> >> trigger)?
> >> >> > >> Atm I just have an object that holds an attribute-wrangle which
> is
> >> >> > working
> >> >> > >> fine. Just curious on other approaches...
> >> >> > >> The Null-OUT workflow will be incorporated, thanks Michael!
> >> >> > >>
> >> >> > >> cheers,
> >> >> > >> Thomas
> >> >> > >>
> >> >> > >> On Tue, Nov 28, 2017 at 6:39 PM Ciaran Moloney <
> >> >> > moloney.ciaran at gmail.com>
> >> >> > >> wrote:
> >> >> > >>
> >> >> > >> > If you're working in a wrangle node, you could just reference
> >> the
> >> >> > input
> >> >> > >> > port and be done with it.
> >> >> > >> >
> >> >> > >> > On Tue, Nov 28, 2017 at 4:59 PM, Michael Dunkley <
> >> >> mdunkley at gmail.com>
> >> >> > >> > wrote:
> >> >> > >> >
> >> >> > >> > > Hey Thomas - the null thing i mentioned isn't required per
> se,
> >> >> just
> >> >> > >> > > best practice and a very common houdini pattern.  Basically
> >> the
> >> >> idea
> >> >> > >> > > is you usually want to reference paths from nulls, if
> >> >> appropriate,
> >> >> > so
> >> >> > >> > > that if your network graph changes (ie you add more relevant
> >> >> > >> > > operations after your wrangle), you don't have to change the
> >> >> > >> > > expression.  I guess the idea is that it makes your logic
> more
> >> >> > >> > > agnostic and less reliant on specific nodes.  My personal
> >> >> approach
> >> >> > is
> >> >> > >> > > to label the nulls in ways that describe the state of the
> >> >> network at
> >> >> > >> > > that point (eg OUT_sim).   Again, not strictly necessary,
> >> just a
> >> >> > >> > > little cleaner than referencing workhorse nodes, and also
> >> works
> >> >> > better
> >> >> > >> > > in cases where, for instance, you decide you want to cache
> the
> >> >> > output
> >> >> > >> > > of your dop network before referencing it.
> >> >> > >> > > For your case i think the network would look something like
> >> >> > >> > > dop_import->null, and you'd then reference that null.
> >> >> > >> > >
> >> >> > >> > > On Tue, Nov 28, 2017 at 11:14 AM, Thomas Volkmann <
> >> >> > >> listmail.3d at gmail.com
> >> >> > >> > >
> >> >> > >> > > wrote:
> >> >> > >> > > > Hi Michael, that works great! The shelf tools seem to do
> the
> >> >> > packing
> >> >> > >> > > > automatically (copy stamp node).
> >> >> > >> > > > What do you mean by pulling from a null sop?
> >> >> > >> > > > So far I can point directly to /DopNetwork or use a merge
> >> node
> >> >> to
> >> >> > >> get
> >> >> > >> > it
> >> >> > >> > > > inside my Geo where I connect it to the wrangle-node (was
> >> just
> >> >> > >> about to
> >> >> > >> > > > test Oliviers approach when your mail came in...thanks
> >> Olivier
> >> >> > I'll
> >> >> > >> > take
> >> >> > >> > > a
> >> >> > >> > > > look at that approach in due time).
> >> >> > >> > > > It's a lot of these 'best practices' that I'm not aware of
> >> >> atm....
> >> >> > >> > > >
> >> >> > >> > > > cheers,
> >> >> > >> > > > Thomas
> >> >> > >> > > >
> >> >> > >> > > > On Tue, Nov 28, 2017 at 4:32 PM Michael Dunkley <
> >> >> > mdunkley at gmail.com
> >> >> > >> >
> >> >> > >> > > wrote:
> >> >> > >> > > >
> >> >> > >> > > >> Hey Thomas.  So far as your expression goes - P is
> usually
> >> a
> >> >> > point
> >> >> > >> > > >> attribute, not a detail, the detail function doesn't
> >> require
> >> >> "op"
> >> >> > >> > > >> syntax, and usually doesn't return an array unless you're
> >> >> asking
> >> >> > >> for
> >> >> > >> > > >> an array attribute.
> >> >> > >> > > >> The expression you're looking for is probably more along
> >> the
> >> >> > lines
> >> >> > >> of:
> >> >> > >> > > >>
> >> >> > >> > > >> vector pos = point("/full_or_relative_path/
> to_node","P",3)
> >> >> > >> > > >>
> >> >> > >> > > >> where the path is just a normal houdini path, the
> >> attribute is
> >> >> > >> > > >> expressed as a string (as you had) and the 3 is simply
> the
> >> >> number
> >> >> > >> of
> >> >> > >> > > >> the rbd you're trying to access.  This is making the
> >> >> assumption
> >> >> > >> that
> >> >> > >> > > >> you're working with packed rbd's, so that the "point
> >> number"
> >> >> > you're
> >> >> > >> > > >> grabbing actually represents an entire packed piece.
> >> Unpacked
> >> >> > >> rbd's
> >> >> > >> > > >> would be slightly trickier to grab.  Haven't watched that
> >> >> Entagma
> >> >> > >> vid,
> >> >> > >> > > >> so i don't know which you're actually working with.
> >> >> > >> > > >> It would also be good practice to pull from a (null) sop
> if
> >> >> > >> possible
> >> >> > >> > > >> (as opposed to dops directly - pulling directly from dops
> >> is
> >> >> > >> certainly
> >> >> > >> > > >> possible, though the syntax is a little screwier and
> >> generally
> >> >> > not
> >> >> > >> > > >> ideal).
> >> >> > >> > > >>
> >> >> > >> > > >>
> >> >> > >> > > >>
> >> >> > >> > > >> On Tue, Nov 28, 2017 at 9:05 AM, Olivier Jeannel <
> >> >> > >> > > facialdeluxe at gmail.com>
> >> >> > >> > > >> wrote:
> >> >> > >> > > >> > I personnaly go with vop.
> >> >> > >> > > >> > Having the points you're working with in the first
> port.
> >> >> > >> > > >> > And the points you're gathering infos from in the
> second
> >> >> port.
> >> >> > >> > > >> > You can either use a PcOpen + Pcfilter (P) if you want
> to
> >> >> get
> >> >> > >> the P
> >> >> > >> > > >> > according to the distance.
> >> >> > >> > > >> > Or use the Import Point (P) based on the id number.
> >> >> > >> > > >> >
> >> >> > >> > > >> > Or go the PrimUV route if you want to gather one
> >> attribute
> >> >> from
> >> >> > >> > > polygon
> >> >> > >> > > >> > location (same as UV to Location in ICE)
> >> >> > >> > > >> >
> >> >> > >> > > >> >
> >> >> > >> > > >> > 2017-11-28 13:46 GMT+01:00 Thomas Volkmann <
> >> >> > >> listmail.3d at gmail.com>:
> >> >> > >> > > >> >
> >> >> > >> > > >> >> A small follow-up:
> >> >> > >> > > >> >> How do I get the position of a certain RigidBody
> >> instance
> >> >> in
> >> >> > >> > another
> >> >> > >> > > >> >> objects pointwrangle?
> >> >> > >> > > >> >>
> >> >> > >> > > >> >> I'm trying:
> >> >> > >> > > >> >> vector pos[] = detail("op:/MyDOP/MyRBD_PackedObject",
> >> >> "P");
> >> >> > >> > > >> >>
> >> >> > >> > > >> >> Any hints?
> >> >> > >> > > >> >> Thanks,
> >> >> > >> > > >> >> Thomas
> >> >> > >> > > >> >>
> >> >> > >> > > >> >> On Mon, Nov 27, 2017 at 2:27 PM Thomas Volkmann <
> >> >> > >> > > listmail.3d at gmail.com>
> >> >> > >> > > >> >> wrote:
> >> >> > >> > > >> >>
> >> >> > >> > > >> >> > Excellent, Thanks!
> >> >> > >> > > >> >> >
> >> >> > >> > > >> >> >
> >> >> > >> > > >> >> > On Mon, Nov 27, 2017 at 1:29 PM Matt Estela <
> >> >> > >> > matt.estela at gmail.com
> >> >> > >> > > >
> >> >> > >> > > >> >> wrote:
> >> >> > >> > > >> >> >
> >> >> > >> > > >> >> >> Grow/shrinking is well covered by this entagma
> >> tutorial:
> >> >> > >> > > >> >> >>
> >> >> > >> > > >> >> >>
> >> http://www.entagma.com/scaling-the-bullets-dynamically/
> >> >> > >> > > >> >> >>
> >> >> > >> > > >> >> >>
> >> >> > >> > > >> >> >> On 27 November 2017 at 23:10, Thomas Volkmann <
> >> >> > >> > > listmail.3d at gmail.com
> >> >> > >> > > >> >
> >> >> > >> > > >> >> >> wrote:
> >> >> > >> > > >> >> >>
> >> >> > >> > > >> >> >> > Hi,
> >> >> > >> > > >> >> >> >
> >> >> > >> > > >> >> >> > I'm taking another dive into Houdini again and
> I'm
> >> >> > having a
> >> >> > >> > very
> >> >> > >> > > >> slow
> >> >> > >> > > >> >> >> start
> >> >> > >> > > >> >> >> > at the moment. It seems I have forgotten some of
> >> the
> >> >> > basic
> >> >> > >> > > >> stuff....
> >> >> > >> > > >> >> >> > So if someone could help me out and save me a
> >> couple
> >> >> of
> >> >> > >> hours
> >> >> > >> > it
> >> >> > >> > > >> would
> >> >> > >> > > >> >> >> be
> >> >> > >> > > >> >> >> > much appreciated.
> >> >> > >> > > >> >> >> >
> >> >> > >> > > >> >> >> > I have a simple RigidBody simulation from some
> >> >> instanced
> >> >> > >> > > objects.
> >> >> > >> > > >> >> >> > Now I would like to do some stuff with some of
> >> these,
> >> >> > like
> >> >> > >> > > select
> >> >> > >> > > >> by
> >> >> > >> > > >> >> ID
> >> >> > >> > > >> >> >> and
> >> >> > >> > > >> >> >> > then putting them to sleep at a certain frame or
> >> have
> >> >> > them
> >> >> > >> > > >> >> >> > growing/shrinking over time.
> >> >> > >> > > >> >> >> >
> >> >> > >> > > >> >> >> > Can I do that stuff all in the same place (some
> >> >> wrangle
> >> >> > >> node /
> >> >> > >> > > >> where?)
> >> >> > >> > > >> >> >> or
> >> >> > >> > > >> >> >> > does the scaling has to happen in a sop and the
> >> sleep
> >> >> in
> >> >> > >> the
> >> >> > >> > > dop?
> >> >> > >> > > >> >> >> > Damn, I really thought I was past that initial
> >> >> confusion
> >> >> > >> when
> >> >> > >> > > >> starting
> >> >> > >> > > >> >> >> with
> >> >> > >> > > >> >> >> > Houdini, but  a couple of months off seem to be a
> >> full
> >> >> > >> reset
> >> >> > >> > on
> >> >> > >> > > my
> >> >> > >> > > >> >> >> brain...
> >> >> > >> > > >> >> >> >
> >> >> > >> > > >> >> >> > Thanks,
> >> >> > >> > > >> >> >> > Thomas
> >> >> > >> > > >> >> >> > _______________________________________________
> >> >> > >> > > >> >> >> > 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
> >> >> > >> > > >> >> >>
> >> >> > >> > > >> >> >
> >> >> > >> > > >> >> _______________________________________________
> >> >> > >> > > >> >> Sidefx-houdini-list mailing list
> >> >> > >> > > >> >> Sidefx-houdini-list at sidefx.com
> >> >> > >> > > >> >> https://lists.sidefx.com:443/m
> >> >> ailman/listinfo/sidefx-houdini
> >> >> > >> -list
> >> >> > >> > > >> >>
> >> >> > >> > > >> > _______________________________________________
> >> >> > >> > > >> > Sidefx-houdini-list mailing list
> >> >> > >> > > >> > Sidefx-houdini-list at sidefx.com
> >> >> > >> > > >> > https://lists.sidefx.com:443/m
> >> >> ailman/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
> >> >> > >> > > >>
> >> >> > >> > > > _______________________________________________
> >> >> > >> > > > 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
> >> >> > >> > >
> >> >> > >> > _______________________________________________
> >> >> > >> > 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
> >> >> > >>
> >> >> > >
> >> >> > >
> >> >> > _______________________________________________
> >> >> > 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
> >> >>
> >> >
> >> >
> >> _______________________________________________
> >> Sidefx-houdini-list mailing list
> >> Sidefx-houdini-list at sidefx.com
> >> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
> >>
> >
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