Alembic packed primitive UV issue

[Arnov]

Hey guys! 

I require help dealing with packed alembic within houdini 17.5/18.

I have a heavy geo but im getting an issue with textures not showing properly unless unpacking but unpacking causes scene to be extremely heavy. 

 

So is it possible to keep it a delayed packed primitive and unpack only the uv attribute to maintain the scene being lighter and yet allows the unpack uv to be read within renderman for houdini. 

 

Any thoughts? 

[davpe]

the reason why packed geometry is so fast is that you don't have access to all the data (unless you unpack it). that is the idea of it - you exchange some flexibility for speed. so what you should do you should do is to prep your assets first as normal geometry, and then use packed data for rendering (so it's fast even with very heavy scenes). at rendering phase it's assumed you don't need to see textures or anything like that in viewport, and the priority is to make things as lightweight as possible. so even very heavy scenes can be manipulated comfortably.

if packed prims allowed what you asking, it would, from nature of things, make things slow again (as you already found out), and therefore there would be no benefit from packing them.

if the geo is too heavy to work with, you have three options - 1) split it first and unpack only the parts you need, 2) get faster workstation or 3) optimize where possible so you have less data to process

[Arnov]

Hi Davpe! 

Thanks for getting back to me! 

You're right on this absolutely . 

So currently, I'm facing an issue with the textures not lining up with the UDIMs unless we unpack while rendering within renderman 21. 

 

Would you be able to help me with an alternative? So I was actually thinking out loud when I mentioned, if it's possible to unpack the UV attribute for the delayer primitive. 

[davpe]

you're welcome.

it is as simple as it gets. either you go back to the original asset, do the adjustments there and export a new version or you have to unpack the geo in houdini and do the changes there. there is no alternative to this i'm afraid.

anyways, i'm not sure what you mean exactly by textures not lining up with UDIMS unless unpacked. packing does not have any effect on how uv coordinates are deployed. if the render looks differently when unpacked my guess is there must be something wrong with how you apply materials/textures in houdini.

[Arnov]

Appreciate your time! 

I have assigned materials either using the material node or packed edit node. 

Let me see if I can get a few pictures up. 

Thank you!!