On the inputs for feOutputProcessEnvelope you have nCount, from_setID[0..nCount-1] and from_vectorID[0..nCount-1]. I'm confused by this as it seems unlikly that your number of output set IDs (from_setID) would match the number of vector IDs (from_vectorID). If the sizes of from_SetID and from_vectorID do not match, then what value do you use for nCount?
Also in the remarks it says that different output vectors may be specified for each ouput set. How?