Hi! I'm a Houdini noob. (Also first post on this forum, if I posted in the wrong place, plz let me know and move my post)

I'm trying to export an alembic cache from maya into houdini and then adding two vtx-attribs, tangents and bitangents.

I tried using this. http://www.houdinitoolbox.com/houdini.php?asset=30 [houdinitoolbox.com]
But I'm not sure what that node is trying to do as it, on output deletes the attributes it is trying to calculate.

Browsing through the tree I also found it expecting the face normal attribute named as “normal” whereas the convert node, connected as:

Alembic reader ->
-> Convert. From All Types to Polygons, connectivity Triangles.

names the normals as “N”.

Then just renaming the attribute from “N” to “normal” produces a weird, smoothed result.

As you can read, I'm quite confused at this point and rambling, please help..

Glad to be learning Houdini though, it's a blast so far!

TLDR;
Trying to add tangents and bitangents to an alembic cache from Maya in Houdini. How would you do it?

Perhaps the PolyFrame SOP will help you?

That worked great!!! Thanks!

One kink to polyframe though, was that it will shuffle all the info to your points (instead of vertices). Thus breaking your “N”'s.
But as long as you tell the polyframe to leave your normals alone and only calculate tangents/bitangents it seems like a solid approach.

Thanks again

No problem.

Btw, you could always submit a Bug if you think some behaviour is erroneous. The transition to full support for vertex Normals is sometimes a little incomplete in places.
https://www.sidefx.com/index.php?option=com_content&task=view&id=768&Itemid=239 [sidefx.com]