This tutorial will show you how to export .ass files from Houdini and import them into other Arnold plugins.

Exporting From Houdini

Creating the Metaballs

A common workflow is going to be creating dynamics in Houdini to be rendered along with other elements in Maya or Softimage. To illustrate this, let's create some blobby metaballs in Houdini.

Pointwrange with Random Point Color VEXpression



Metaballs converted to polygons


Create A Shader With HtoA Nodes

Let's add some color to the geometry using some HtoA specific nodes.


Export .ass Sequence

Now, let's export this geometry as a sequence of .ass files for use in Maya or Softimage.

Arnold ROP Archive settings

Importing To Maya

Creating An Animated Stand-In

Now switch over to Maya to import the geometry we've created.

Stand-in attributes


In order to use a frame sequence, the Maya time node needs to be connected to the frame parameter.


A timeToUnitConversion node will automatically be added.



Adding Shader Searchpaths

If the scene is rendered at this point, the geometry will appear white.


In order for Arnold for Maya to use these shaders, the location of the HtoA shaders needs to be added to the Shader Search Path.
The Search Paths are in the Render Settings under the System tab. 


Gamma Settings

Now it should render with the colors from the ramp_rgb node. However, it may be too dark.

Now we have geometry created from particles and metaballs in Houdini using HtoA shaders rendering in Arnold for Maya.

Importing To Houdini

Search Paths

If an .ass file containing specific shaders was imported into Houdini then the Search Path would need to be filled in.