Stoke Field Data Exporter

Available in Stoke MX 2.0 and higher. Last Edited on May 16, 2014.

Introduction

The Stoke Field Exporter is a tool for exporting Stoke Field objects to 3rd party Field Data formats - FumeFX .FXD, Field3D .F3D and OpenVDB .VDB. The resulting files or file sequence can then be loaded in other plugins or applications including FumeFX in 3ds Max and Maya, or back in 3ds Max using the Stoke Field Loader object or the Magma InputField operator.

Accessing The Field Data Exporter

The Stoke Field Exporter is available from the Stoke menu in the 3ds Max Main Menu.

Only one instance of the Exporter can be opened at any given time.

User Interface

../../_images/stk2_field_data_exporter_ui.png

Source Controls

Stoke Field scene object to Export drop-down list

  • Lists all supported Field objects in the current scene.
  • Used to specify the Field to export.

Refresh button

  • Updates the content of the drop-down list in case new objects have been created since the opening of the tool.

Save Frame Range group of controls

From Frame spinner

  • Specifies the first frame of the range to export.
  • Defaults to the first frame of the scene range.

To Frame spinner

  • Specifies the last frame of the range to export.
  • Defaults to the last frame of the scene range.

Scene Range button

  • Pressing this button (re)sets the export range to the scene range.

Render Range button

  • Pressing this button sets the export range to the render range.

Current Frame button

  • Pressing this button sets both the From Frame and To Frame values to the current frame of the Time Slider.

Save Path group of controls

Base field and button

  • The field defines the base path of the output file.
  • Default is $default, which expands to the user’s Stoke Data Export folder.
  • Pressing the button opens a context menu with the following options:
    • RESET to $default - set the text field to the $default token.
    • PICK A New Base Path… - lets you select any absolute path as the root folder for output.
    • EXPLORE Base Output Folder… - reveals the current base path in a Windows Explorer.

Proj. field and button

  • Specifies the Project name, creating a folder underneath the Base path.
  • The Project name will be stored to an INI file and restored in following sessions - it has to be changed manually as needed.
  • Pressing the button will display a list of all previously used project names, as well as the option to explore the current project folder.

Ver. field and button

  • Specifies the version of the output, creating a sub-folder underneath the Project folder.
  • When the Exporter tool is opened or the Base or Project folders are changed, the Version field will be set to the next version based on the highest existing version.
  • Pressing the buttin opens a context menu with the following options:
    • NEW Version [v00X] - creates a new sub-folder with the given number.
    • v00Y - sets the Version to the specified existing sub-folder.
    • EXPLORE Current Version Folder [v00X] - reveals the current version folder’s path in a Windows Explorer.

File field and button

  • Specifies the output file name.
  • Default is $object, which uses the object’s name as the file name.
  • Pressing the button opens a context menu with the following options:
    • RESET to $object - resets the field to the default $object token.
    • COPY PATH To Windows Clipboard - copies the path portion of the file name to the Windows Clipboard so it can be pasted elsewhere.
    • COPY FILENAME To Windows Clipboard - copies the whole output file name including path, name and extension to the Windows Clipboard to be pasted elsewhere, for example in a Stoke Field Loader’s file dialog.
    • EXPLORE Output Folder… - reveals the current output path in a Windows Explorer.

File Format drop-down list

  • Specifies the output file format to export to.
  • Possible values are:
    • .FXD - save to the FumeFX file format.
    • .F3D - save to the Sony Pictures Imageworks’ Field3D file format.
    • .VDB - save to the DreamWorkd OpenVDB file format.

Switch All Scene Objects To Render State checkbox

  • Unchecked by default.
  • When checked, all scene objects will be switched to render state in order to export fields based on the render settings of particles, meshes etc.
  • When unchecked, the viewport state of objects including particles systems and meshes will be used to generate the field data to be exported.

EXPORT Stoke Field Data To … Files…

  • Performs the actual exporting operation.
  • The text on the button will change depending on the File Type selected.
  • The button will be disabled if no valid Field source object is selected.

NOTES About FumeFX Export

Channels

When exporting to F3D and VDB file formats, the channel names specified in the source field will be saved to disk since both support arbitrary channel names. In the case of FumeFX .FXD files though, the channel layout is fixed and the source fields must provide compatible channels to produce valid data in the saved sequence. The following rules apply:

  • Density channel in Stoke fields will be saved as FumeFX Smoke channel.
  • Positive Fire channel values in Stoke fields will be saved as FumeFX Fire channel.
  • Negative Fire channel values in Stoke fields will be saved as FumeFX Fuel channel.
  • TextureCoord channel values in Stoke fields will be saved as FumeFX FluidMapping channel.
  • Velocity and Temperature Stoke channels will be stored as Velocity and Temperature in FumeFX.

Grid Size And Location

FumeFX Grids support only positive coordinates in their voxel addresses, and all data is in object space. The Stoke Field Grid can contain both positive and negative voxel addresses and is processed in world space. Thus, some adjustments have to be performed to the FXD data to produce a valid FumeFX file, and you might have to deal with transforming the FumeFX Grid to match the location of the Stoke Field simulation.

In particular, the resulting .FXD files will have the origin at the bottom center of the source field’s grid.

To help with the translation, a MAXScript .MS file will be written out when saving to FXD file format. This script will contain the grid size and spacing, sequence filename and grid translation. Running this script will attempt to create a FumeFX simulation grid with the correct settings.

Pre-Requisites

Saving .FXD files is performed by Stoke using a FumeFX library shipping with the Stoke package. It does not require a FumeFX installation.

Loading .FXD files using Stoke Field Loader or the Magma InputField node requires a FumeFX installation as it uses the FumeFX libraries.