November 10th, 2017
This version uses the Arnold 18.104.22.168 core.
MtoA 2.1.0 is the version included in Maya 2018 Update 2. It contains lots of improvements and bugfixes.
The AOV editor has been refactored to simplify the use of recent AOV controls :
A video showing the AOV improvements in MtoA 2.1.0 can be found here.
A video showing the new ARV features in MtoA 2.1.0 can be found here.
A new, more accurate way of calculating SSS has been added. Unlike the current empirical BSSRDF method based on diffusion theory, this new method actually traces below the surface with a real random walk and makes no assumptions about the geometry being locally flat. This means it can take into account anisotropic scattering like brute-force volume rendering and produces much better results around concavities and small details. It can also be substantially faster for large scattering radius (i.e. large mean free path) compared to the old method. On the other hand, the new method can be slower in dense media (i.e. small mfp), does not support sss_setname for blending two surfaces together, may require redialing materials to achieve a similar look, and is more sensitive to non-closed meshes, "mouth bags", eyeballs, and internal geometry potentially casting shadows. This new algorithm is exposed in the aiStandardSurface shader via the new parameters subsurface_type (with enum values diffusion and randomwalk) and subsurface_anisotropy (Henyey-Greenstein's eccentricity parameter 'g' from -1.0 to +1.0). The default is to use the old empirical diffusion method in order not to break the look of existing scenes.
A video showing the new Subsurface Scattering can be found here.
We are now shipping a dedicated shader for car paint, which can be thought of as the combination of a simplified version of the aiStandardSurface and aiFlakes shaders. This shader can create a wide range of car paint looks without having to connect several nodes. For example, a pearlescent effect can be easily added to both the specular and flakes layers by simply tweaking a few parameters such as specular_flip_flop and flake_flip_flop. An arbitrary number of layers of flakes can be used (flake_layers). The flakes at a deep layer are covered by the ones closest to the surface and more tinted by pigments (specified by the transmission_color parameter).
Many improvements were added to the shadow matte shader in Arnold 5.0.2 based on user feedback, and MtoA now exposes these improvements:
A video showing the improvements in the Shadow Matte shader can be found here.
Since Arnold 5, each standin is automatically namespaced to avoid name collisions, but this prevented from exporting shapes and shaders as separate standins. In Arnold 22.214.171.124 an optional namespace attribute was added to StandIns. By setting the same namespace on different standins, their nodes will be able to "connect" with each other. This will allow exporting shapes and shaders separately, as in Arnold 4. The parameter "Force Translate Shading Engines" (that is necessary for this workflow) has been renamed "Force Shader Assignments" in the export options UI, and only appears when "Export Shaders" is turned off.
A video showing the new features in StandIns and procedurals can be found here.
Subdivision patches outside the view or dicing camera frustum will not be subdivided. This is useful for any extended surface that is only partially visible as only the directly visible part will be subdivided, potentially saving memory and subdivision time. Similarly, no subdivision work will happen if a mesh is not directly visible. This can be turned on globally by enabling the Render Settings parameter Subdivision Frustum Culling and can be turned off for specific meshes with aiSubdivFrustumIgnore (perhaps to avoid artifacts in hard cast shadows, reflections, etc). The option aiSubdivFrustumPadding adds a world space padding to the frustum that can be increased as needed to minimize artifacts from objects that straddle the frustum boundaries. Note that motion blur is not yet taken into account and moving objects might require some additional padding.
A video showing the new Subdivision Frustum Culling can be found here.
MtoA always used to export a Maya-specific MayaShadingEngine at the root of all shading trees. This is no longer the case in MtoA 2.1.0. Apart from decreasing the number of shader nodes in an Arnold scene, which increases efficiency, this also makes it easier to render .ass files exported from Maya in other DCC plugins. Previously saved .ass files are still compatible. However, previously exported XGen archives might not render properly. As a workaround for eventual pipeline specific regressions, a temporary parameter Export Shading Engines (Legacy) was added in the Render Settings (in Tab "System").
|#2665||Can't resize programmatically ARV in Maya 2017|
|#3208||lookdevkit shaders don't batch render when you load MtoA with userSetup.mel|
|#2093||Intensity attribute in the mesh_light should be a slider|
|#2105||Enlarge post, pre render mel callbacks interface|
|#2600||Camera Filtermap icon does not work|
|#2732||Add XGen orientation to Arnold curves|
|#2835||Duplicating an object resets aiTranslator|
|#2855||All previously-installed versions of MtoA appear in Start > All Programs in Windows 7|
|#2922||Minimum pixel width crashes|
|#2939||mtoa_shaders loaded twice|
|#2946||Errors of "Extension already managed" on Linux and Mac with latest MtoA|
|#3107||Risk of clashing node names in onConnectionChanged callback.|
|#3115||Large numbers of AOVs slow scene open time|
|#3149||Resize ARV in Maya 2018 when needed|
|#3178||IPR restarts render when opening the Render Settings window (Maya 2018)|
|#3180||Regression in AOVs during batch render|
|#3181||Geometries randomly missing|
|#3183||shadow_matte AOV indirect_specular isn't exposed|
|#3184||Image plane not seen by Shadow Matte secondary bounces|
|#3185||Add offscreen_color to Image Plane|
|#3187||Render setup regression tests fail if MtoA is loaded|
|#3190||IPR Update issue : changing shaders connections in shading groups|
|#3195||Expose car paint shader|
|#3197||[ARV] A/B handles not always visible|
|#3201||Export All Shading Groups not exporting displacements|
|#3203||Loading MtoA plugin in mayapy and then exiting causes crash|
|#3207||[ARV] Cameras list not always up-to-date with Maya|
|#3213||Xgen archive shaders not rendered in interactive sessions|
|#3223||ARV : Opening the viewer without rendering shows wrong resolution size|
|#3224||Rename bifrost procedural folder name to lower case|
|#3226||Add test for MtoA ABI compatibility|
|#3228||Curve collector transform applied twice|
|#3229||Camera filtermap icon doesn't work|
|#3231||Expose Transmit AOVs|
|#3233||arnoldScene could return the list of created Arnold objects|
|#3236||ARV : Crashes when picking on the viewer after opening a new scene|
|#3237||Standins exported without bbox show a simple line in the viewport|
|#3239||Export subdiv frustum culling|
|#2826||[ARV] Show snapshots AOVs when snapshots folder is set|
|#2961||Give autogenerated procedural Maya UIs the same features as AiStandin|
|#3108||Replace .asstoc by .ass metadata|
|#2948||Zoom ARV centered on cursor like Maya Render View|
|#3054||Review MtoA debug logs|
|#3148||Add post-translation callback|
|#3162||Improve AOVs window|
|#3170||Support per-camera AOV|
|#3174||Implement Standins namespacing|
|#3176||Procedural translator in meshes is missing parameters|
|#3194||ARV : mid mouse button should pan the image|
|#3198||[ARV] Support view transforms list in toolbar|
|#3212||Add menu to create custom shapes|
|#3215||Export XGen archives with the surface shader|
|#3222||ARV: Enabling "use snapshots folder" should open the browser|
|#3225||Add export full paths option in render settings|