Computer Animation Ying Zhu Georgia State University Hair and fur

How to create hair? Create an object. In Object (F7) panel, click on “Particle Buttons” icon Add a new particle system Select “Hair” type Can add multiple hair systems for one object

Adjust amount of hair Under “particle system” tab, adjust “Amount”

Adjust amount of hair with “children” It’s often more efficient to keep a relatively low number in “Amount” and add “Children” Go to “Children” tab Select Children from “Faces” The “Amount” in this tab is the number of child hairs displayed in the 3D view (set lower for efficient editing) The “Render Amount” is the number of child hairs displayed in the rendered image (set higher for better visual quality)

Adjust amount of hair with “children” If you have 1000 parent particles you need 50 to 100 children Thin hair (blond) need more child particles Thick hair (black) need less child particles Press “Kink/Branch” to create curly or wavy hairs

Adjust the length of the hair Under “Physics” tab, adjust “Initial velocity” to change hair length Adjust the “Normal” velocity to change hair length (e.g. 0.05 for fur) Adjust “Random” to vary the hair length (e.g. 0.005) Adjust AccX/AccY/AccZ to change hair direction

Segments The “Segments” value in the “Particle System” tab Each hair strand is simulated as a curve The “Segments” value is the number of control points on the curve The more segment you have, the more flexible you can manipulate the hair Therefore add more segments for longer hair

Decide where to grow hair There are three ways to specify the areas on a 3D mesh where you want the hair to grow Use vertex group Use UV mapping (finer control but more complex) Use Particle Edit tool in Particle Mode (easier to use)

Use vertex group to control hair growth Select the Emitter, enter Edit mode Select the faces on the 3D model that you want hair/fur to grow from Under “Link and Materials” tab, create a new Vertex Group Give it a meaningful name (e.g. skin) Press “Assign” button to assign the selected faces to the vertex group

Use vertex group to control hair growth Go to the “Particle Buttons” panel In “Extras” tab, under “Vertex group”, click on the button on the right side of the “Neg” button Select the name of the vertex group you just created In the “Attribute” drop down menu, choose “Density” Now hair only grow from the faces that belong to that vertex group

Control hair growth with UV mapping This method works better than the vertex group method when you only have a small number of polygons on the 3D mesh model A little complicated though Check out this tutorial http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/Furry

Control hair growth in Particle Mode This is probably the easiest and the most interactive method

Editing hair In “Particle System” tab, press “Set Editable” button In 3D view window, switch to “Particle Mode” Press N to bring out the “Particle Edit Properties” window Add and Cut Comb Puff Smooth Adjust Length

Editing hair Once you start to edit hair in Particle Mode, you won’t be able to adjust parameters in “Particle Buttons” window Unless you press “Free Edit” button, but then you’ll lose all the editing done in the Particle Mode. Therefore set the “Amount” and the hair length to the desired value before pressing “Set Editable”

Hair and force field You can also use force fields to change hair style Create an empty object and create a force field (e.g. sphere, vortex, wind, etc.) Move the force field closer to the hair

Hair and Curve Guide Add a Bezier curve In Object (F7) panel, click on “Physics Buttons” icon Under “Fields”, select “Curve Guide” type Move the curve closer to the hair Enter Edit mode to manipulate the curve, which in turn manipulates the hair

Adjust the shape and thickness of hair strand In “Particle buttons” panel, under “Visualization” tab Press “Strand render” Go to Shading (F5) and “Material buttons” panel In “Links and Pipeline” tab, under “Render Pipeline”, press “Stands” button For a detailed explanation see http://wiki.blender.org/index.php/Doc:Manual/Materials/Properties/Strands

Adjust the shape and thickness of hair strand For black hair Start 0.86 End 0.854 Shape -0.686 For blond hair Use Blender Units Start 0.003 End 0.002 Minimum 2 Shape 0 (or -0.5)

Creating materials for hair Create a material for the hair and set the base color The color of the hair is governed by the specular highlights (Spec), so you may want to set the Spec color too Press “Ztransp” to make hair semi-transparent

Add more realism Make the hair strand fade towards the tip Create a texture for the hair material Go to “Texure buttons” panel, select “Blend” texture type Choose either Lin(ear) or Quad blend Go back to the “Material buttons” panel Set “Map Input” to Strand Set “Map to” to Alpha “DVar” to 0

Blond hair For material settings of Blond hair, check out http://wiki.blender.org/uploads/4/45/Blender3D_BlondHairStill-2.48a.blend