Pack SOP and optimization

[art3mis]

Trying to understand the whens and whys to use a Pack SOP and packed Geometry in general.

Is it a good idea to always 'pack' your geometry before caching it?

 

ie in the attached network am I getting any extra optimization by using a Pack SOP?

Edited July 16, 2017 by art3mis

[DennisSchmidt]

There is a great explanation about packed primitives on the SideFX help doc: http://www.sidefx.com/docs/houdini/model/packed

In your case, I don't think it makes much a difference. If you use packed primitive you are not compressing anything. It's just keeping it in memory and just using a small amount of ram for referencing it. But if you are planning to copy it multiple times it makes sense to use packed primitives. Since then it will refer to the geometry already stored in memory and also drawing it in the viewport will be much quicker since it uses the data already stored and just adds a different transform to draw it.
If it's just for rendering I would recommend using packed disk primitive in the file load. Since that creates a reference to the file on disk rather than having it in memory. This is also very efficient for viewport display and rendering. As well as for copying(same as before with packed primitives, only you have to unpack to do any changes other than transforms). For very big scenes this comes in handy as it creates a reference to the file on disk and especially for IFD's the size won't grow as much.