So I spent an insane amount of time last week trying to get hair / fur in Houdini to show up when using Redshift render engine. I was looking at all sorts of tutorials and not one of them mentioned this freaking setting to make it work. You have to toggle the Hair Generation from “Generate Geo in Mantra” to “Use SOP Geo”. BAM, everything works. Took me forever to find it. Hopefully, this saves you the same headache.