If you want a Particle Source to follow a Null, you can just stick
ch("/obj/MY_NULL/tx")
(etc) into the Position boxes.
But that'll only work if the Null itself is animated/translated. If it's parented to something else, you'll just get
{0,0,0}
out. So how do I get the Null object's position in world space? I've found optransform(), but it doesn't seem very stuff-it-in-a-parameter-as-an-expression-friendly, if you get me.
(And whenever you're controlling something's location/rotation with expressions, you always end up with three separate copies of your expression as Vectors are always broken out into separate axes in the UI, when often it would be easier to be able to just use a Vector. Is there any way to have Houdini kinda munge translation or rotation parameters into a nice single expression-friendly Vector type box?)
Have you checked out the RMB menu on a parameter? Try going to Reference->Scene Data and then in the selection dialog find your target obj and look under Transforms->World. This will populate the parameter with a bunch of expressions (that you probably wouldn't want to type by hand )
Oh, if it was going to an obj node's transforms, constraints totally the way to go.
I was thinking that we were looking at sticking an objects world space translate into a vector parm buried in a dopnet or some such… In which case you could possibly export the t channels from a Get World Space chop node, but the reference->scene data was fewer clicks
Have you checked out the RMB menu on a parameter? Try going to Reference->Scene Data and then in the selection dialog find your target obj and look under Transforms->World. This will populate the parameter with a bunch of expressions (that you probably wouldn't want to type by hand )
Have you checked out the RMB menu on a parameter? Try going to Reference->Scene Data and then in the selection dialog find your target obj and look under Transforms->World. This will populate the parameter with a bunch of expressions (that you probably wouldn't want to type by hand )
This is the greatest thing in the world. Thank you so much!