New version of Alembic import shader

Here’s a new version of the abcimport shader that is compatible with mental ray 3.12 and mental ray for Maya 2015. It can be downloaded from this link. The package contains a version for Windows, Linux and Mac OS X, as well as the .mi file with the new shader declaration.

The new features:

  • Support for hair import
    Alembic curve objects are translated into mental ray hair geometry. The curves can be defined with linear segments, quadratic bezier and cubic b-spline (either uniform or with given knot vector). Hair approximation quality can be set with the shader parameter “subdivisions”  (default 0). The parameter controls the number of subdivisions for hair segments. The picture shows a rendering of an Alembic file generated by Ornatrix 3, with linear hair segments and using the shader “mib_illum_hair_x”.hair from abcimport                                                                         Hair alembic file courtesy Ephere Inc
  • Faceset material support
    In Maya, the facesets are assigned with material names. Our abcimport shader now uses this information to reference materials with these names. Facesets can be either triangle or polygon mesh. (Facesets for subdivision surfaces will be added later.) Faceset translation is enabled by default and can be turned off by setting the shader parameter “facesetmaterials” to off.
  • User data support
    Triangle meshes now can reference user data such as color3, color4, point, normal, float, integer. The user data must be attached as “arbitrary geometry parameter property” to objects in the abc file. Please, contact us for more details.
  • Subdivision control for hair, NURBS and subdivision surfaces
    The “subdivision” parameter is now also applied to hair, NURBS trim curves, NURBS, and subdivision surfaces.
  • Motion blur issues fixed
    Motion blur for topology changing abc files is now possible. We fixed an issue with the velocities in Alembic which were not interpreted correctly.

These features will be incorporated into the upcoming versions of mental ray this year.

11 thoughts on “New version of Alembic import shader

  1. This sounds like a great feature!

    Sorry for being a bit offtopic, but would it be possible for you to make a blog post about the mib_illum_hair_x? There isn’t any documentation about it – or at least I can’t find any – and I don’t really know how all these parameters work. The image posted above looks great, so this is why I’m asking as I don’t know how I could achieve this level of realism.

      1. Justin says:

        I’ve had ALOT of problems with noise in reflections using this shader in animation. I can’t resolve this noise and haven’t been able to use it in production as a result, despite my really wanting to use it. Are you guys getting this kind of noise? It’s only in animation it shows up, stills are ok. I’m on Maya 2015 SP5.

  2. Dizzy says:

    Can we assume that Max mental ray development has pretty much stopped now? looking at this blog, there is almost nothing about Max in the last year, and it’s mostly about Maya.

    1. nvsteffen says:

      This is an update of the Alembic shader that can be used with mental ray in any application, Maya or 3ds Max. However, Maya offers a workflow that can load Alembic geometry only on demand at render time, called “GPU Cache”, whereas 3ds Max supports Alembic primarily just as a scene exchange format not passing through mental ray (Maya does this as well, btw). So yes, this update helps mental ray for Maya users immediately. On the other hand, I could imagine ways to connect the demand-loading Alembic feature to existing 3ds Max functionality, for example “mr Proxy”. If such a feature is planned to be added to 3ds Max sounds like a good question to the product team at Autodesk.

  3. Dizzy says:

    nvsteffen, thanks for the reply. Contacting Autodesk; there is the user-voice option, which is consistently ignored, and any other questions lead nowhere due to the policy of not talking about future features (which could affect the all-important share price).

    I love mentalray, but I have lost all faith in Autodesk.

    1. nvsteffen says:

      Hi Dizzy, I believe if there is enough demand from users like you for Alembic caches in 3ds Max it will come. Do you use Alembic in your daily work ? For scene exchange or just for fast geometry caching ?

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