Packed Disk Sequenc Offsetting

[mathiasj]

Hi there. I'm trying to offset the animation of packed disk instances but can't get it to work. What's the best workflow?

Tried both .bgeo 'index' and alembic 'abcframe' (though bgeo might not be supported according to docs?)
When loading alembics I looked into the Proxy Import SOP as well, but docs suggest just using native Alembic SOP.

Houdini 20.5.410 / V-ray 6.20.24

[Morbid Angel]

You would need to type the expression in alembic loader such as frame: $FF + (offserFrame) so it would be $FF + 10. You can also add a timeshift node and do the same there.

[mathiasj]

Thanks you, not sure it would work with my randomized setup though? I am doing that after instancing.

I'm loading in the Alembic, then adding it as an object for the Copy to Points and then after using a Wrangle to randomize the 'abcframe' attribute of the points.
Works fine in the viewport, but V-ray isn't picking it up on render.

[hsz]

Can you post the .hip? or a repro.

[mathiasj]

Thanks. Attached a simple .hip of my setup.

[leo_bao]

Thanks you, not sure it would work with my randomized setup though? I am doing that after instancing.

I'm loading in the Alembic, then adding it as an object for the Copy to Points and then after using a Wrangle to randomize the 'abcframe' attribute of the points.
Works fine in the viewport, but V-ray isn't picking it up on render.

vray does have this problem with "setprimintrinsic" VEX function when it read abcframe, But only in CPU mode though, GPU mode has no problem...
If you use bgeo file, Both CPU and GPU mode would be fine, You could simply write something like this in attrubute wrangle to offsetting bgeo's frame:




And connect an instance sop after it.

[mathiasj]

Oh usually it's CPU that stable and not GPU so I didn't test for that.
Thanks, I'll see if I can get it going.

[bdancer]

> vray does have this problem with "setprimintrinsic" VEX function when it read abcframe

Thanks! Will be fixed in the next nightly.

[mathiasj]

vray does have this problem with "setprimintrinsic" VEX function when it read abcframe, But only in CPU mode though, GPU mode has no problem...
If you use bgeo file, Both CPU and GPU mode would be fine, You could simply write something like this in attrubute wrangle to offsetting bgeo's frame:

And connect an instance sop after it.

Got both your methods working. Thanks!

Wondering if it would be good to get the 'setprimintrinsic' 'index' method working for .bgeo as well though.
Read that the bgeo 'instancefile' with Instance SOP method can be very heavy for Redshift at least.

I guess for very heavy scenes you could convert to a V-ray Proxy.

[leo_bao]

Got both your methods working. Thanks!

Wondering if it would be good to get the 'setprimintrinsic' 'index' method working for .bgeo as well though.
Read that the bgeo 'instancefile' with Instance SOP method can be very heavy for Redshift at least.

I guess for very heavy scenes you could convert to a V-ray Proxy.

If you wanna use Redshift as your renderer, You could use Redshift proxy to speed up your scene, So it wouldn't be heavy anymore.
You could simply lay down an attribute wrangle, and connect that has "setprimintrinsic" VEX function's node as input 2, And write this down:

The idea is use "primintrinsic" VEX function to read "index" of "setprimintrinsic" from upstream node, And then combine it in a path that Redshift proxy can read just like instance sop method.
But in this method have a viewport bug: you can't see anything that loaded in Redshift proxy in viewport, But your render would be fine.
If you wanna see, then you have to turn on your upstream node that has "setprimintrinsic" VEX function's node.

[mathiasj]

Thanks Leo it wasn't to actually use Redshift, just that I'd read of Redshift having a performance problem with the Instance method, where others then exported to a proxy to help. Just thought the same could be the case for V-ray Proxies in case there were performance problems.
Will have to do some tests to see if it happens I guess.

But it works at least!

[leo_bao]

Thanks Leo it wasn't to actually use Redshift, just that I'd read of Redshift having a performance problem with the Instance method, where others then exported to a proxy to help. Just thought the same could be the case for V-ray Proxies in case there were performance problems.
Will have to do some tests to see if it happens I guess.

But it works at least!

vray proxy would have performance problem too.. Hope development team could improve this..
I got only 1000 spheres in the scene and viewport fps drop down to 3.8fps

performance_test.rar

[bdancer]

> Hope development team could improve this..

I've written a few messages about abcframe fix, will this work for you?
Could you please try some recent stable nightly?

> I got only 1000 spheres in the scene and viewport fps drop down to 3.8fps

For V-Ray for Houdini we recoomend using Alembic and all native Houdini's Alembic related SOP nodes.
There are no plans improving V-Ray Proxy import node; I'm also not sure about your FPS issues, I'm getting >120:

[leo_bao]

> Hope development team could improve this..

I've written a few messages about abcframe fix, will this work for you?
Could you please try some recent stable nightly?

> I got only 1000 spheres in the scene and viewport fps drop down to 3.8fps

For V-Ray for Houdini we recoomend using Alembic and all native Houdini's Alembic related SOP nodes.
There are no plans improving V-Ray Proxy import node; I'm also not sure about your FPS issues, I'm getting >120:

I've written a few messages about abcframe fix, will this work for you?
It worked.

Could you please try some recent stable nightly?
in vray for houdini 6.20.25 [7409b9be], problem has been solved, good job!

I'm also not sure about your FPS issues, I'm getting >120
when I playing animation, it would be drop down to 3.8fps. when I pause, we are getting the same FPS.

[bdancer]

> when I playing animation, it would be drop down to 3.8fps. when I pause, we are getting the same FPS.

Got you, well, as I wrote, there are no plans improving proxy import SOP workflow.

> 6.20.25 [7409b9be]?

I don't remember those numbers by heart sorry =) E.g. this one from today: https://nightlies.chaos.com/#/vray6h...e/6.2/20250123