If the Number of samples is set to 0 for the XSIAmbientOcclusion shader, Softimage 2010 memory usage will go through the roof as soon as Softimage has to render. This didn’t happen in 7.5, so it’s easy to load up an existing scene, open the Material Manager or Render Tree, and then see Softimage hang up while rendering a shaderball. That’s how this issue was originally discovered.

On a related note, here’s a JScript snippet that shows how to find all the XSIAmbientOcclusion shaders and check the samples values.

// XSIAmbientOcclusion Class ID
var sClassID = "{FF66A9F8-BB42-480D-834D-BC5FC6E3AD23}"
var oColl = FindObjects( null, sClassID ) ;

oEnum = new Enumerator( oColl ) ;
for (;!oEnum.atEnd();oEnum.moveNext() )
{
	var oAOShader = oEnum.item() ;
	LogMessage( oAOShader.Parameters("samples").Value );
//	LogMessage( oAOShader.samples.Value );
}