How to render hair and fur?



Hair Geometry


Corona Renderer supports the following plugins for generating hair geometry:



Hair Material


Hair has particular unique qualities that need a dedicated shader. The CoronaHairMtl shader is physically accurate, and handles the unique highlights and transmission properties that hair requires, while still rendering quickly and giving you the ease of use in controlling the material that you expect from Corona Renderer.

The hair material is mainly intended for creating human hair and animal fur, as it includes properties based on natural hair model (melanin pigment amount, anisotropic reflections, hair fiber caustics), however it can be as well used to render carpet strands, fuzzy fabrics, nylon strings, and other types of synthetic fibers. 


Note: to apply the hair material to hair generated using the native 3ds Max Hair and Fur modifier, select the modifier, and drag-and-drop the material under the "Custom shader" rollout ("mr shader" in older versions of 3ds Max).



CoronaHairMod Modifier


The CoronaHairMod modifier can be used to control the "level of detail" of the hair geometry. By default, each hair strand is rendered as a flat 2D plane to achieve the best rendering speed at the cost of some realism. Using this modifier, you can force Corona to render hair as 3D tubes, which is useful for close-ups (e.g. eyelashes when the camera is zoomed in on an eye). Generally, for shots where the shape of each individual hair strand is not visible up close, it is best to use the default settings for optimal performance and quality. 




By default, when the CoronaHairMod modifier is not used, hair strands are rendered as flat planes.


The CoronaHairMod modifier can be used to render hair as 3D tubes, which is useful for close-ups. 




Examples


Usually, adjusting various parameters of the hair material is needed, depending on the kind of hair that is to be rendered. Below you will find a list of basic hair material examples:


Default hair material settings. This is what we get out of the box, when a CoronaHairMtl is created. 



Color > Level under Basic options changed to 0 (from the default 1). This results in completely black hair. 



Melanin lowered to 0 (from the default 0,5). This results in completely white hair.


Melanin lowered to 0,25 (from the default 0,5). This results in brighter, blonder hair, compared to the default rendering.



Melanin increased to 0,75 (from the default 0,5). This results in darker, brown hair, compared to the default rendering.



Pheomelanin increased to 1 (from the default 0). This results in reddish hue visible in the hair.



Diffuse color changed to blue (from the default black). This results in hair appearing covered with a layer of paint, or some other material, which is added on top of it. It can be used to add dust or dirt to the hair. 



See also:

How to render skin?