Good day


Anybody have experience with how to instance volume with time offset ?


Retime instance LOP unfortunately doesn't work properly

oslo
Retime instance LOP unfortunately doesn't work properly

Could you be more specific? Perhaps post a simple example file?

https://we.tl/t-hegUcXKafP [we.tl]

In order to be able to retime your references, you need to cache the SOP Import so that all the volume data is available on the stage at the same time. Retime Instances isn't a TimeShift LOP - it doesn't recook its inputs, it just adjusts USD parameters, which means all the data needs to be on the stage at the same time.

Second, you had the Retime Instances node set to Point Instancer mode. But then you told it to retime individual references. So you should have had it in Native Instance mode. It should probably have been triggering an error in this case.

Finally, Retime Instances only seems to work if the prims you point it at are marked as instanceable. I have no idea why this would be the case, and I'd call this a bug, but at the moment it seems to be true. So you need to change the Instancer to create Instanceable References, not simple References.

Attached is a functioning version of the file. Updated to also have a frameoffset primvar, to demonstrate that the offset can be made different per-volume.

Thanks for the detailed description

hi, I am using Houdini 20.5. and that new version still cannot do VDB volume instance with random time offset, as same as usd points can.

For instance, if we use instance SOP in SOP level, we can shift each instance's timeOffset from cache frames.

Can we use volume LOPs and pointInstance with random time offset in houdini 20.5? Or still not working? Ideally I don't want to re-cache the VDB volumes in LOP


Also, I tested LOP_instance_timeOffset.hip. Yes, viewport result is great! but it produces a lot of vdb caches because of using SOP_import node. However, I wonder why it creates 50 files of even number vdb files. where is even number's file name from, and why 50 files are produced although instance point counts are 25, when using a default fileCache LOP. (maybe half of points are using the same instance frame numbers..)

I found an article for the solution!
https://forums.odforce.net/topic/54119-set-timing-offsets-on-solaris-instances-solved/ [forums.odforce.net]