Up Vector For Primitives

[Pearl]

Hi,

I have a sphere with faceted polygons that I'd like to rotate individually, but I can't get the primitives to line up properly. I'm doing this with POPs, so I'd like the up vectors to be properly lined up.

I attached pictures of what I currently have, and what I would like. The first one is when I just birth particles from primitive centers. Notice how the y-axis of each particle is not lined up. The second picture I achieved within POPs (UpVector), which doesn't work very well when I bring it back out again*. I would like to make the green y-axis line up like the second picture without using any POPs.

* If I use the UpVector POP to manipulate the up vectors, the primitive reads that as a NEW normal, so it aligns weirdly to the new vectors when I use a Primitive SOP.

I hope I'm explaining myself correctly.

Let me try rephrasing one more time:

Is there a way to give primitives up vectors? So that I don't need to manipulate them when I get into POPs.

Thanks for any help!

Edited: To add the .hip file. There's not much there, but basically I'm just trying to line up my copied primitives so I can do stuff to them later.

sphere_rotatePoly_help.hip

[TheUsualAlex]

nihao! I could be wrong, but I don't think you can really give primitive an up vector per se... When you generated the up vector in your POP network, these vectors are applied to the point itself. What you probably want is set normal properly for each of these particles in how you want your primitive to be aligned, then set the up vectors accordingly to lock down the frame of reference. This should allow you to orient your primitive however you wish according to N and Up.

HOpe that cleared up a little..

[Pearl]

Nihao, TheUsualAlex. I poked around Houdini and couldn't figure out how to manipulate the up vectors correctly. The normals are always right. It's the up vectors that are not listening to me.

I'll keep poking.

Thanks for your help.