Copy Arnold StandIn

   5848   7   2
User Avatar
Member
61 posts
Joined: Feb. 2011
Offline
I'm struggling with copying a mesh to A LOT of points.
Since it gets very heavy in Maya to copy a mesh of 20 polygons to something like 5 million points,
I was thinking of creating an Arnold StandIn and copy that instead.
Unfortunately, when selecting the StandIn, I get this error:
“Selection has no supported object that can be used for input.”

Does anybody have an idea if this is at all possible or maybe a tip for another way to do this?

I'm currently working with Houdini 15.5 Indie licenses and in Maya 2016.

Thanks!
- A little nonsense now and then, is relished by the wisest men.
User Avatar
Member
818 posts
Joined: Sept. 2013
Offline
Arnold StandIn cannot be used as inputs. I'm not too familiar with MtoA. Does it support rendering instancing efficiently (without using Arnold StandIn)? If so, the simplest way would be to make use of packed primitives. For example, you'd pack the 20 polygons object as a packed primitive, and then copy it to the 5 million points. When these 5 million packed primitives are outputted into Maya, it'd be outputted as Maya particle instancer.

If MtoA doesn't support rendering Maya instancer, then maybe another way is for the asset to only output the 5 million points, without copying the 20 polygons. The points would be outputted into Maya as particles. In Maya, you can then use Maya's particle instancer to instance the Arnold StandIn onto these 5 million points.

Hope this helps!
Andrew / アンドリュー
User Avatar
Member
61 posts
Joined: Feb. 2011
Offline
Even though Maya would be able to render the instances, it seems the best option is the 2nd one.
It should work with outputting just the points and then instancing the stand-ins onto those.

Thanks!
- A little nonsense now and then, is relished by the wisest men.
User Avatar
Member
61 posts
Joined: Feb. 2011
Offline
So far everything seems to be working. Except I'm running into a troublesome issue.

Normally I can see the points that get scattered, but sometimes they disappear, never to be seen again.
The thing is that I know they are still there, because I added the option to copy a box from within the HDA to the points.
When activating that option, the boxes get copied to where the points are.
But when deactivating the copying again, the points are still not visible.

Any clue on what could be happening? Maybe a viewport bug?
I've added a Maya2016 file and HDA in attachment. I hope it works if you want to test it.

Thanks!

Attachments:
scattertest.mb (209.2 KB)
ScatterToGeometry.hda (53.8 KB)

- A little nonsense now and then, is relished by the wisest men.
User Avatar
Member
818 posts
Joined: Sept. 2013
Offline
You might just need to do a “sync”. After toggling the “Copy Test Geo” option, you need to do a “sync”, because that option changes the type of what the asset is outputting. For example, when the option is “on”, a mesh node needs to be created in Maya to receive the asset's outputs. When the option is “off”, a particle node needs to be created. Doing a “sync” will sync up the Maya nodes to match what the asset needs.
Andrew / アンドリュー
User Avatar
Member
61 posts
Joined: Feb. 2011
Offline
Sadly enough, I've already tried that to no avail.
As well as reloading the HDA and changing other parameters that do not change the output type and then doing a sync.
- A little nonsense now and then, is relished by the wisest men.
User Avatar
Member
818 posts
Joined: Sept. 2013
Offline
After clicking sync, did the particle node get created? What about changing the frames? If you're not at the start frame, Maya has an issue where particles tend to not update properly until the frame changes.
Andrew / アンドリュー
User Avatar
Member
61 posts
Joined: Feb. 2011
Offline
Changing the frame seems to work.
Thanks for the tip!
- A little nonsense now and then, is relished by the wisest men.
  • Quick Links