Hi Rotem, thanks for the comments.
Lighting:
With regards lighting we try to keep it simple. Generally a classic 3/4 point lighting setup will give you a good result out of the box so to speak. When the need calls for it, we will create a "light dome" to fake a GI look.
You create a hemisphere of spot lights, with lowish shadow map resolutions for speed, and then create a dome around your subject firing light at it from all sides. Around 16 lights is a good number. They are very low intensity but can really help sell the render. If in doubt though, keep it simple.
Rendering:In terms of render passes, you have to get a bit creative due to the fact that hairfarm is basically an atmospheric so its not like doing multi-pass compositing whereby you can rebuild it lateron. We use Vray and it has some shaders which can help you out.
Normals pass - You can use the Vray Sampler Info shader and set it to normals to give you a normals pass for the hair. This is great for relighting. I posted a link on the chaos group forums about how to use it as shown below. You can also recreate this shader using falloffs with 3ds max standard materials.
Attachment:
Colour correction - We also create a few colour correction passes. You can map the root to tip of the hair with pure red and pure blue for example and this will allow you to create masks in comp to darken or lighten these areas.
Occlusion - We create a very fake occlusion by just mapping white at the tips and black at the roots and making the shader 100% self illuminated. If you don't have a heavy scene you can convert to geometry and do a proper occlusion but often this isn't viable.
We have been recently experimenting with Krakatoa as a volumetric renderer and the results are really promising as it just slots into the pipeline right after hairfarm. It has a great inbuilt look and it also implements the shader they used on King Kong for the hair which looks great.
Hope this helps!
Regards,
Mark