Hi,

Using Houdini Indie 19.5.534, I've simulated a test in the SOP context using Vellum. There is soft body, hair, grains and cloth simulation going on. I cached this using a "File Cache" node as a series of .bgeo.sc files and the cached animation plays back rather quickly in the OBJ/SOP context.

However, when I import the scene into Solaris (i.e. the STAGE context), playback grinds to a halt. It takes like 10 or 20 seconds for a frame to update.

Any idea how I can fix this? Why are things going so much slower when they're imported into Solaris? By the way, I'm using the "Scene Import (All)" node.

Thanks for letting me know :-)

bgeo files are a native geometry format that can be loaded quickly into memory. Importing onto the stage requires converting to USD format. It's pretty fast, but if you have a lot of attributes it can slow down. The importer won't know whether the topology is static and which attributes are unchanging. configuring the import with hints as to which attributes are changing, whether or not the topology is static, and which attributes to import can massively improve performance. With a scene import, the configuration has to be done in SOPs using the USDConfigure SOP. The sopimport node in Solaris has a similar set of controls but doesn't import object hierarchies or lights and cameras.

jsmack
bgeo files are a native geometry format that can be loaded quickly into memory. Importing onto the stage requires converting to USD format. It's pretty fast, but if you have a lot of attributes it can slow down. The importer won't know whether the topology is static and which attributes are unchanging. configuring the import with hints as to which attributes are changing, whether or not the topology is static, and which attributes to import can massively improve performance. With a scene import, the configuration has to be done in SOPs using the USDConfigure SOP. The sopimport node in Solaris has a similar set of controls but doesn't import object hierarchies or lights and cameras.

Thanks a lot for the detailed reply. This makes sense. I don't guess there's a tutorial that deals with the 'correct' setup in more detail?

In the meantime I started doing some more testing myself, using "SOP Create" nodes to create the simulation in SOPs, but inside Solaris. At first this didn't seem to work, but I've now managed to get pretty fluid playback in Solaris (the trick seems to be to not give any geometry to the grain simulation, as Solaris seems to choke on that).

However, this is causing another problem now. Somehow there is 'phantom geometry' hanging around that I can't seem to get rid of. It's the initial position of the grains that seems to remain no matter what.



I checked the cached simulation in the OBJ/SOP context and there is nothing there. But once you load the sim in Solaris/SOP it shows up out of nowhere. Any idea how I could fix that? That'd be much appreciated.