[Bf-usd] Hello!

Fri Oct 30 03:30:56 CET 2020

Well hello there everyone!

Hi Mark! Yeah there are a few folks using Blender, but not (to my knowledge
yet) anyone using the Blender USD Export.

Thanks Blazej as well for the update; very excited to see hdCycles
released, and looking forward to Blender's expanded USD import/export
features!

Cheers!

On Mon, Oct 26, 2020 at 6:10 PM Blazej Floch <
blazej.floch at tangent-animation.com> wrote:

> Hi everyone,
>
> I'm the pipeline supervisor at Tangent Animation.
>
> I am glad that you bring up some of the points. We are already somewhat
> involved into developing Usd handling in Blender, that goes beyond just
> im-/export.
> As we speak our main developer, Charles Wardlaw, has been trying to answer
> some of the question of how to handle edits of referenced Usd data.
>
> For us Layout and Rigs in Animation are the main use-cases, which someone
> dictates our approach.
>
> As opposed to Houdini we went with the Animal Logic-, now Autodesk, way of
> handling the references among the native blender hierarchy.
> We may also end-up representing our edits in an Usd SessionLayer, while
> exposing the controls via a native blender element (comparable to the
> ephemeral Proxy objects in Maya).
>
> This work among the Usd im- and export on our side will be available
> shortly (currently awaiting clearance from legal).
>
> The other work is hdcycles, already available in our github repository:
> https://github.com/tangent-opensource/hdcycles
>
> Some more additions to it are also planned to be released soon.
> We're glad that the Blender Foundation started the Usd integration and
> hope we can contribute our work based on it for a broader ecosystem of DCCs
> utilizing Usd.
>
> That being said - we are working under production constraints, so it may
> be a mere starting-point that needs more work to make if viable for a
> broader audience within Blender.
> We hope that this will get clearer once the code is released and spawn-off
> more discussions.
> Then we hopefully can also shed some light on our workflows that will
> allow asset, layout and animation work in Blender, while playing nicely
> with other workflows in Houdini via Usd exchange.
>
> I am also curious about the potential that this might bring to other
> studios, as blender shines in certain workflows and it would be interesting
> to see how opening it up to existing pipelines via Usd affects its role in
> the production landscape.
>
> Cheers,
> Blazej Floch
>
> ------------------------------
> *From:* Bf-usd <bf-usd-bounces at blender.org> on behalf of Mark Tucker <
> mtucker at sidefx.com>
> *Sent:* Monday, October 26, 2020 16:28
> *To:* bf-usd at blender.org <bf-usd at blender.org>
> *Subject:* Re: [Bf-usd] Hello!
>
> Of course! At least the first part of the question. The second part I can
> give some opinions...
>
> Houdini's USD integration sprang from a desire to implement a new
> (Katana-like) node based look development and lighting environment within
> Houdini, called Solaris. We determined that USD (combined with Hydra)
> provided many of the critical capabilities that our users wanted in this
> new context, so we decided to build this new context from the ground up
> around USD.
>
> So as of version 18.0, Houdini ships with the USD library built in. There
> is a new node context called LOPs which provides native editing of USD
> data. Which is to say LOPs load USD data directly, manipulates it directly
> as USD, display it in the 3D viewport using the Hydra framework, and
> outputs USD. Many LOPs focus on look development and lighting-specific
> tasks, but we also provide LOP nodes for more generic USD authoring tasks
> (such as creating variants, adding references, authoring USD Point
> Instancer primitives, etc).
>
> Because this USD editing all happens within a specific Houdini context,
> the user can choose whether to use USD exclusively, of Houdini
> representations exclusively, or combine their capabilities using explicit
> translation nodes (import from LOPs into SOPs or SOPs into LOPs). But our
> plan in the fairly near term is to convince users to move all lighting work
> into the Solaris/LOP context.
>
> This is the front page of the Houdini documentation relating to Solaris
> for more information:
> https://www.sidefx.com/docs/houdini/solaris/index.html Or please feel
> free to ask more detailed questions.
>
> As for Blender (and any DCC integrating with USD through explicit
> Import/Export translation workflows) the difficult part, I think, is the
> export step. USD is always read in as a composed stage (and so the import
> step can be handled like any other external data format). But that stage is
> made up of many, many layer files. Often multiple files contribute to any
> given primitive in the scene graph. So authoring changes to the stage
> requires an understanding of how those changes will be consumed by the next
> application in the pipeline. And there are limitations on what kinds of
> edits can be performed, depending on how the edits are applied. The
> application may want to directly edit one or more source layers. Or it may
> author overrides to a particular branch of the scene graph that needs to be
> referenced onto the stage. Or it can author scene-wide overrides that must
> be applied as a sublayer. Or it can author only brand new data (no
> overrides) that can then be brought back onto the stage using any USD
> composition arc.
>
> Looking at this document: https://developer.blender.org/T68933, it sounds
> to me like it might align well with the "author a new sublayer" approach?
> The Blender Collection sounds like it could contain the loaded objects from
> the USD stage, and hold configuration information for writing out changes
> to the stage authored within the blender session? But I know nothing about
> how Blender would represent such edits internally prior to exporting them...
>
> A simpler integration could take the last approach, where Blender is not
> capable of overriding existing scene graph data, and instead only authors
> brand new primitives. If Blender is being used primarily as a modeler this
> is a perfectly viable (if more limited) style of integration, but it does
> not line up with all the use cases described in that design document.
>
> Mark
>
> On 10/26/2020 5:04:54 AM, Ton Roosendaal <ton at blender.org> wrote:
>
> Hi Mark,
>
> A very interesting question for you then is:  can you share info on how
> Houdini integrates with USD and how to make sure Blender will work
> flawlessly in mixed software pipelines?
>
> Thanks,
> -Ton-
> ----------------------------------------------------------------------
> Ton Roosendaal - ton at blender.org - www.blender.org
> Chairman Blender Foundation, Director Blender Institute
> Buikslotermeerplein 161, 1025 ET Amsterdam, the Netherlands
>
>
> On 26/10/2020 00:57, Mark Tucker wrote:
>
> My intent was to stay on topic, but perhaps I was not clear in my
> question. Let me try again:
>
> Is Blue Sky using Blender to produce USD assets in production at the
> moment? And if so, can you tell us a little bit about the process.
>
> I am happy to have this conversation off-list with Chris if you would
> prefer, Ton. I am new to this list, and there has not been a lot of
> traffic, so I'm just making some guesses about what would constitute on and
> off topic here.
>
> Thanks,
> Mark
>
> On 10/25/2020 9:46:33 AM, Ton Roosendaal <ton at blender.org>
> <ton at blender.org> wrote:
>
> Hi,
>
> It looks like a diverse range of companies participate in this list now.
> Everyone's really welcome!
>
> However, I always insist on a strict policy to stay on topic on our
> mailing lists. We are here to discuss how to improve Blender with USD
> integration.
>
> If you are curious to hear who's using Blender for what, please use
> private mails.
>
> Thanks,
> -Ton-
> ----------------------------------------------------------------------
> Ton Roosendaal - ton at blender.org - www.blender.org
> Chairman Blender Foundation, Director Blender Institute
> Buikslotermeerplein 161, 1025 ET Amsterdam, the Netherlands
>
>
> On 25/10/2020 04:19, Mark Tucker wrote:
>
> Hi Chris!
>
> Is Blue Sky using Blender in production at the moment?
>
> Mark
>
> On 10/24/2020 9:26:47 PM, Chris Rydalch <crydalch at gmail.com>
> <crydalch at gmail.com> wrote:
> Hello! I'm Chris Rydalch, I'm in Production Technology at Blue Sky,
> helping with our new pipeline. I’m primarily involved with USD Workflows
> and tools, particularly Houdini; but I’m really excited to see where USD
> and Blender will go.
>
> Looking forward to joining the discussions!
>
> Thanks!
>
> Chris
> -- Bf-usd mailing list Bf-usd at blender.org
> https://lists.blender.org/mailman/listinfo/bf-usd
>
>
>
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