Memory use: alembic vs v-ray proxies / arnold standins etc

[Fredrik Averpil]

Hi everyone,

In the Maya 2014 docs, it says:

Complex scenes and animations can be exported as an Alembic file, and then re-imported into Maya to improve playback performance and reduce memory use.

Now, how would this compare to – let's say – the memory use of V-Ray proxy files?

Is it comparable or is the memory use of Alembic substantially higher than the memory use of V-Ray proxies? (which can reduce memory a lot in extremely highpoly/complex scenes)

I am not familiar with how these formats are structured or how they are read by renderers, so this qualifies as a noob question. And I'm a little lazy as I am on parental leave, as I haven't conducted any tests prior to asking this ;)

Regards,

Fredrik

[Stefan Andersson]

if you just import a alembic file into maya it will still become geometry. So there is little gain in that sense, I think the documents are referring to if you have a large scene with animated objects. So it will become a geo cached scene without a rig. Alembic caching is extremely effective though, so the memory footprint is much less than using maya cache.

I don't know how vray works, but with Arnold you can use Alembic as a procedural, (which almost becomes a aiStandin). Then you release the full power of alembic, Milk vfx made a litte video of the alemvic-procedural workflow.

I hope it's still there

https://docs.google.com/file/d/0B0OS4n2vdeomOU90bUVUSllXcUk

But basically a alembic procedural or a aiStandin become a locator. So it's the same as a vray proxy I guess.

regards

stefan andersson

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Stefan Andersson

Digital Janitor @ MPC ( London )

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[matt estela]

Rambly, probably incorrect musings based on what I know about alembic, proxies, how alternative setups were done at AL....

One of the key benefits of alembic is its opensourceness and its platform agnosticism. If you need to shuttle animated meshes from maya to houdini and back, alembic is perfect. Similarly, if you want to strip a heavy animation rig and have a clean cache to work with for your lighters in maya, alembic is great.

Ideally you want to continue that platform independence through to the renderer. You've written the mesh data out to a .abc file on disk once, you want the maya->render translator to just stick a placeholder in the in the render file. So for prman/3delight in the .rib, or in the arnold .ass file, or in the mentalray .mi file, or in the vray (whatever suffix they use) file, there'd be a line like

DeferredLoad '/path/to/your/alembicfile.abc'

The lamest thing that could happen would be if your renderer doesn't natively read alembic, so it'd ask maya to load the alembic mesh, convert it it to polys, and send that to the renderer. In that case you're actually wasting time rather than saving time.

So.

If vray has native alembic support, and maya-vray understands maya's alembic implementation and doesn't rely on maya to convert, then yes, totally use alembic.

If it doesn't, stick with vray proxies for the moment, and ask Vlad n co when they'll be supporting native alembic in maya. :)

[matt estela]

Heh, Stefan and I basically said exactly the same thing. *high five*

[Fredrik Averpil]

I actually saw that video today (3DPRO) and that sparked the idea of replacing our V-Ray proxies with Alembic. :)

According to Vlado... You *can* feed an Alembic file into a V-Ray proxy node, which will give you some of the performance benefits, though .vrmesh files tend to be a bit faster to work with and are perhaps a bit more memory efficient.

[Ryan O'Phelan]

I can vouch for the alembic in vray proxy to be the best implementation that I've found.  Not only does it treat it as a deferred load,  but it automatically assigns a proxy shader that gives you access to the different pieces of geo in your alembic.  Plus you can see a partial mesh,  or load the full mesh to visualize details If you need to.

R

On Mar 23, 2014 6:26 PM, "Fredrik Averpil" <fredrik...@gmail.com> wrote:

I actually saw that video today (3DPRO) and that sparked the idea of replacing our V-Ray proxies with Alembic. :)

According to Vlado... You *can* feed an Alembic file into a V-Ray proxy node, which will give you some of the performance benefits, though .vrmesh files tend to be a bit faster to work with and are perhaps a bit more memory efficient.

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