Clarification on instancing

Houdini Integrated Plugin

Moderator: juanjgon

gigglebooster
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Joined: Fri May 17, 2019 2:01 pm

Hi. Could someone please clarify instancing with Octane and Houdini for me? Specifically when using the copy to points node? I've looked at this extensively on the forums but it's still unclear, my professor wasn't sure on this either. If you just check the "pack and instance" checkbox on the copy to points node will that function correctly with Octane? Or do I need to do the method shown in the forums where you create a new @instance attribute? When we check the "pack and instance" checkbox on the copy to points node it seems to function correctly, but I've read that it's not actually instancing. Also, if checking this box doesn't work and I need to create the @instance attribute, how would I do that using the copy to points node? The example shown in the forums doesn't use a copy node, it just creates an @instance attribute using an attribute create node that points to the object you want to copy in the string field, and then it does the instancing at render time, but I don't know how to do this using the copy nodes, doesn't seem like you can actually control this method like you could using the copy to points node.
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juanjgon
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Hi,

The plugin doesn't support the instancing at the SOP level yet, for example from the copy SOP. For instancing you need to use the @instance point attribute, or the Instance OBJ node.

Hope it helps,
-Juanjo
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varomix
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Hi Juanjo
I've been using the copy to points with the Pack and Instance option and it seems to work fine

are you saying this aren't Instances to Octane at render time?
instances
instances
thanks
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juanjgon
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Yes, in you scene the packed primitives are fully expanded to mesh geometry. They are not instanced at all.

Thanks,
-Juanjo
davidyannick_1
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juanjgon wrote:Yes, in you scene the packed primitives are fully expanded to mesh geometry. They are not instanced at all.

Thanks,
-Juanjo
Support for packed primitive is planned ?
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juanjgon
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You can instance packed primitives, but not at the SOP level yet. If you have an object built using packed primitives, you can instance it using another Instance OBJ node, or suing any other node using the "instance" point attribute pointing to the packed primitives object path.

Thanks,
-Juanjo
davidyannick_1
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I work with very large scene and millions of instances, for now I have to render in redshift :/ is instancing at the SOP level implementation is planned ?
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juanjgon
Octane Plugin Developer
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Yes, it is planned in the short-term. The first step, supporting the instancing from .bgeo files using the "instancefile" point attribute is ready for the next build. The next step will be the sop level packed geo instancing.

Thanks,
-Juanjo
WoutTgh
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juanjgon wrote:Yes, it is planned in the short-term. The first step, supporting the instancing from .bgeo files using the "instancefile" point attribute is ready for the next build. The next step will be the sop level packed geo instancing.

Thanks,
-Juanjo
Coool, that's great :)
miko3d
Licensed Customer
Posts: 70
Joined: Sat Mar 01, 2014 7:30 pm

Hey Juan

Do we know if Octane has a cap limit for maximum number of instance PClouds?

I Cant find any info about this from OTOY and Im having serious trouble going any higher than the 10 ish million mark.Octane/Houdini just hangs while preprocessing the scene.

The GPUs we are testing have plenty of spare Ram (Tesla 16GB Vram) and ,at around 8-9 million, we are just using around 5GB on VRAM.


Can anyone please try this "Piggygeddon" attached simple scene and report how far can you push the instance number before crashing?


As we cant export the ORBX (houdini hangs at preprocessing scene) ,I'm not sure if this Houdini or Core issue .Any information on this will be very helpful.

Thanks
Mikel.
Attachments
piggygeddon.zip
instance simple test scene
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