New and Exciting Features of V-Ray 3.0 - V-Ray Hair & Fur
Paul Hatton dives into the hair and fur solutions available in 3ds Max, using V-Ray, Ornatrix and Hair Farm...
Today we're going to briefly look at the hair and fur tools within 3ds Max and then focus specifically on how these tools can be utilised with the V-Ray Hair & Fur tools. Chaos Group have gone to great lengths to improve their rendering engine to make rendering hair and fur as realistic as possible. Their tools are compatible with all the major hair plug-ins and formats including Ornatrix and Hair Farm but you can use it with 3ds Max Hair & Fur as well as V-Ray Fur which is what we'll be doing today.
Without any extra plug-ins there are two primary ways of creating hair/fur in 3ds Max. The first is to use the modifier that ships with 3ds Max. This is called Hair & Fur. If you want to do everything using native Chaos Group products then you can utilize the V-Ray fur object type found in the create panel of 3ds Max. We'll explore both these options in the next few steps.
Create your base object
No matter what hair option you use, you are going to need a base object for that hair to be applied to. So if you're creating a rug then this will probably be a plane or if it is the hair of a person then it is likely to be the head. It's important to note at this point that the base object does NOT have to actually be the object the hair comes out of it. Your head for example might have a really dense set of polygons which make using hair on it unmanageable. If this is the case, just use a lower density alternative.
3ds Max Hair & Fur Modifier
Select your object and apply the 3ds Max Hair & Fur modifier. This will give you a generic set of hair strands which if you hit render will not be visible! Helpful! You'll first need to head over to ‘Effects' by pressing 8 and changing the tab. Select your ‘Hair and Fur' and set the ‘Hairs' to ‘mr prim' in the ‘Hair and Fur' rollout. That should do the trick. Hit render and view your incredible creation!
The modifier offers some really cool tools for styling the hair which unfortunately are not similarly available with the V-Ray Fur option. Simple select your modifier and go to the ‘Styling' rollout. Click ‘Style Hair' and you'll notice that all the buttons become active. You can brush the hair or even give the model a haircut! For a more refined style you can select individual hair strands and apply your styling only to those. There are quite a few other tools but the best way to investigate these is to have a play!
V-Ray Hair Material
Now we could use a normal boring V-Ray material but like I said that would be boring! Chaos Group has given us their very own ‘VRayHair' material which is optimized for use with the V-Ray rendering engine. Brilliant. Create the material from the V-Ray materials rollout in the material editor, and set the preset to ‘Red shiny'. To apply it to your hair, select your hair and scroll to the ‘mr Parameters' rollout. Check ‘Apply mr Shader' and drag your hair material into the slot. Render again to see your gorgeous redhead!
Customizing your hair material
With the hair material open you'll notice that V-Ray have given us control over the diffuse, both the primary and secondary specular as well as the transmission. If we focus on the transmission component, this according to the help files ‘corresponds to light that is reflected off the back surface of the hair strands'. An amount of 1 will apply the full color whereas decreasing amounts will decrease the impact of the color. You can also adjust the length and width of the glossy look of the hair. Very cool feature!
Introducing V-Ray Fur
The alternative option to the 3ds Max modifier is the ‘V-Ray Fur' object type. To apply this simply select your base object, head to the create panel and choose ‘V-Ray' from the drop-down. Select ‘VRayFur' and watch the fur get applied to your object. On this bumpy plane the default out of the box settings would work well for a shaggy carpet or rug. You can adjust the length, thickness, bend and so on, as well as specify placement based on a material ID.
Introducing styling V-Ray Fur
If I'm being honest, the V-Ray styling options are rather complicated for the average user. 3ds Max provides interactive styling tools which make the process very natural. V-Ray on the other hand provides a ‘map' based solution to adjusting the strand lengths, bends, thicknesses and so on. This for me is far less intuitive. Both the bend and initial direction options take RGB maps whereby the red component is offset along the u texture direction, the green component is the offset along the v texture direction, and the blue component is the offset along the surface normal. The other options are simple mono maps.
V-Ray Fur styling in action
A common desire with V-Ray Fur and specifically with rugs is to be able to comb all of the strands in a set direction. You can do this by inserting an RGB map into the ‘Bend direction map' slot. 3ds max has a handy ‘RGB Tint' map which you can apply to this slot. You'll notice that all the hairs bend in a more uniform direction. For a more customized look you'll need to create a customized RGB map and apply that instead.
Hopefully this article has given you a brief overview of what is possible with hair and fur and how V-Ray ties into that. Essentially there are multiple options to creating the actual hair (3ds Max, V-Ray, Ornatrix etc.) and then V-Ray offer a bespoke VRayHairMtl which gives you greater power of what the hair looks like. This material is also optimized for use with the V-Ray render engine so it's a perfect option if want to keep everything optimized. Let me encourage you to experiment, check the help files and track down some other tutorials which will help cover aspects that I didn't have time to.
Top tip 1: Animate your V-Ray Fur Styling
Because the V-Ray Fur styling is map driving, you can animated the properties of your maps to create some animated styling. Try putting a ‘Gradient' map into the length parameter and key frame the ‘Color 2 Position' from 0 to 1. You'll notice your grass/rug strands are growing over time!
Top tip 2: Control the memory usage
When dealing with huge numbers of hair strands it's important to think about viewport performance. V-Ray Fur enables you to specify the maximum number hairs that are displayed. Find this parameter in the ‘Viewport display' rollout of the object in the modify panel.
New and exciting features of V-Ray 3.0
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V-Ray 3.0: New Features: V-Ray RT explained
V-Ray 3.0: New Features: Interface and Frame Buffer
V-Ray 3.0: New Features - Faster Rendering
V-Ray 3.0 New Features: A guide to the V-Ray clipper