I have a scene with a couple of animals. It renders really fast without the main horse’s fur. Anyway, that’s not an issue.
Problem is that i don’t know how to lighten the scene. Check this two pictures. In the first one i’m not rendering the body’s hair of the horse. And in the second one i am. But the result is awful.
There’s a trick with alpha channel also. But i really don’t get results in Alpha 2.52 (tutorials are for previous versions, when things were different guess)
Lighting fur is really difficult,it’s one of the most challenging thing you can do.
The reasons are simple.
Lighting standard mesh (surfaces) use the normals of the object,but fur uses the tangents,which are the directions found along the fur curve.
So you’ll never be able to match this 2 different directions.
To solve you have to use surface diffuse(found in the strand parameters),which allows to use the normal information of the emitter to shade the fur.
If you do short and no specular fur ,with the help of selfshadowing done by the shadow buffers(it’s really important to have also a good shadow ON the fur to avoid a flat boring look),surface diffuse works really well.
But,if you plan to do also some specularity(for example if you want to do your horse black and giving it a silk majestic look)well, you are in trouble,because surface diffuse uses the normals,but specular uses the tangents,and there is no way to force specularity to use emitter information for this(it means that the specular isn’t in the place where is expected to be ).
And,worst,tangents aren’t correct,they seem related to the emitter mesh topology so you’ll have a jumping random look for short fur(I have posted a bug entry some time ago about this)
So,as a general rule,use surface diffuse,shadow buffers and try to avoid using specular,if you don’t do black animals it can give an acceptable look…