Arnold Scene Source (.ass) is the native scene definition format, stored in human-readable, editable ASCII files.

Exporting To .ASS

MtoA lets you save scenes to .ass files that can later be rendered outside of Maya with Kick (a multi-platform, command-line utility) or used for rendering via stand-ins.

From the File > Export All/Export Selection menus, select ASS Export as the file type. The dialog will show some Arnold-related options under the File Type Specific Options section of the Options area of the dialog.

Use gzip Compression (.ass.gz)

Exports the scene directly to gzip-compressed files with the .ass.gz extension. You can expect compression rates in the 4-5x range (compared to full ASCII form, obviously there will be a lower compression ratio if the binary encoding option is being used).

Export Bounding Box

Specify whether bounding box of the exported scene is included in a separate .asstoc file.

Use Binary Encoding

Specify whether binary encoding is used to compress large arrays ( bigger than 16) containing float in their components. They are encoded into a more compact ASCII representation (b85), leading to smaller files and faster load times, while still being mostly human-readable. Also, the binary encoding has exact 32-bit precision, whereas without this binary output floating point values are truncated into at most 8 ASCII digits (e.g. 1234.5678). The encoded arrays are indicated by prefixing the array type with "b85" as in the example below. POINT2, POINT, and VECTOR arrays are encoded. 16 float



name mymesh

nsides 54 1 UINT  3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

 4 4 4 4 4 3 3 3 3 3 3 3 3 3

vlist 47 1 b85POINT

 LJ4iv4THCEE/NV4/1nPCvhpuBkEMk10/LJ4iv2uf+kDVzHI/36OGvhkc/kD9+Fs/LGenvtmU8EDqJVo/l1cGv+Ij50D1 ... 

Export Node Types

You can also specify which of the following types of nodes are included in the .ass export:

Force Translation of Shading Engines

Will export the 'Shading Engine' of the objects in the scene to the ass file, but not the shading network derived from them.

This option decouples the geometry ass file from the shader's ass file and allows the user to externally control the shading assignments.

Export All Shading Groups

When enabled, all shading groups are exported (or only the selected ones during export selected), even if they're not assigned to any geometry in the scene. This prevents assignment of shaders to dummy objects.

Light Linking

Turn off light linking ('None') or use Maya's light links ('Maya Light Links').

Shadow Linking

Shadow linking can be set to be the same as the setting for light linking ('Follows Light Linking') or you can specify explicitly that shadow linking should be turned off ('None') or use Maya's shadow linking ('Maya Shadow Links').


Exports a sequence of .ass files based on the number of frames set in Start/End.


Specifies the start frame of the sequence to be exported.


Specifies the end frame of the sequence to be exported.


The increment between the frames to be exported.