Hi

I have a bunch of scattered debris on the floor using instance with spraypaint inside. I am attaching a usd rop set to flatten stage to try to export my mesh (scattered object into the 100s)

Just to test it I am then loading the usd file into Maya expecting to see all the debris scattered over the floor. But I actually see just the raw meshes, not the baked out 100s of pieces of debris.

Is there a workflow I am missing to "freeze/bake/cook" the instance LOP out. How would you use instance if you are using more than Houdini to render usd? (I am only using Houdini myself, but I really want to just load the mega mesh/primitive back into Houdini will all the gazzilionb bits of debris).

I can upload a file, but it is rather huge for everything. All I am really struggling with is the principle of it.

Best. Mark

EDIT: OK I have found a solution if anyone else was wondering. It's not pretty but it works. Under the instance LOP drop down a sopmodify with the export to SOPs option set to "unpack USD Primatives to polygons", then inside the SOP, drop down an unpackusd, followed by a rop_alembic. This Alembic can then be brought back into Houdini and turned into a USD. Phew! Best

Houdini's Instancer LOP should just be creating a run of the mill USD point instancer prim. I would have thought Maya would be able to load that... But that aside, if what you want is a single mesh made up of thousands of little pieces, you probably should have just skipped the Instancer LOP. Create your scattered pieces in SOPs, make sure you unpack any prims in SOPs, and just SOP Import the resulting mesh into LOPs.

Or, if for some reason you still want to use the Instancer LOP, there's no reason to write out to Alembic... Just do what you described, using a LOP Import and unpack the USD prims down to polygons, then use a SOP Import (not connected to the original Point instancer LOP, start a brand new LOP node chain) to pull the unpacked meshes into LOPs as a single big mesh.

But again, I am very surprised Maya isn't importing a point instancer properly...

Hi Mark. Thanks for that.

Yep. Maya is... Maya. I was testing against the latest usd build for Maya 2002.4 but it was just a test. Being able to import into Nuke, UE4 is the reason I wanted to test "freezing out". Maya was just to hand.

Out of interest if I am rendering from Solaris using PDG to deadline on our farm is there any cpu speed advantage to creating 1000s of bit of geo, or should I just leave it as instanced? It takes Houdini's viewport a bit of time to catch up with materials assigned when it is instanced so I was wondering if it is the same for rendering.

I still need to do a bit more testing as I am more inclined to think it might not be instancing at all slowing it down but materials in material library recalculating each time. I also want to see if I can disable usd preview surface to speed things up a bit as well. (sorry for me rambling, just my inner thoughts)

I cannot use our render farm to test all of this until June which which is why I am a little bit unsure right now.

Best

Mark

Instancing is almost universally better. Not if you have 100 different things with only one or two instances each, but certainly once you have 10 or more instances of a given thing I think instancing should always be better than a bunch of unique things. I suspect whatever slowdown you are blaming on instancing when it comes to materials is in fact something else.

Hi Mark. Thanks for all the info. Also thanks for the heads up about what is not slowing thing down. I'll try to do a bit more testing to see what is slowing things down. Have a good one!