When designing fur you need to do different
styling at different locations of a model. FurDesigner uses a very powerfull
styling technique that allows you to make almost any look you can think
of.
Normally you keyframe things over time.
In FurDesigner you KeyPoint parameters over the surface of a object. The
KeyMap is defined by interpolating the KeyPoints. For any given surface
FurDesigner attatches a KeyMap like the one shown here:
The Keymap is UV mapped on the surface,
as a texturemap is UV mapped in Softimages texture editor. In FurDesigner
the lower left corner maps to UV cooridinate 0,0 on the surface, and the
upper right corner maps to UV cooridinate 1.1.
Each parameter in FurDesigner (Length,
Color, Wave etc.) is called a Channel and any Channel can be KeyMapped.
Basic KeyMapping:
In this tutorial we will KeyMap the Length Channel on a grid.
In Softimage, make a default b-spline grid and move the camera to 0,10,-20. Then bring the scene into FurDesigner.
Select the grid and make 50 hairs pr. square unit. Set the length slider at 4.0 to make the hairs longer.
Press down the "A"-button (Add) for the Length Channel. This means that the Length Channel will be active for the new key.
Press down left mouse button anywhere on the KeyMap and drag the mouse around while holding the left mouse button down. Notice the key is drawn in the graphics window as a small 'normal', tagged with the key number.
Drag this Key to the right side of the KeyMap area and release the mouse.
This first Key has all Channels active.
You need at least one Key of all Channels to edit the values. Before adding
the first Key, it was virtually there, just not at any specific UV coordinate
as it is now.
When there's only one active Key for any
given Channel, that key will have global influence.
Add another Length Key by pressing anywhere on the KeyMap area again, this time drag it to the left side of the KeyMap area.
The new Key is blue, which indicates that this Key is selected. Key 1 is now unselected, thus drawn yellow.
Pull down the length slider to 0.2. This sets the Length Channel for Key 2 (which is selected) at 0.2 and the length is now interpolated between Key 1 and Key 2.
Press "Render selection"
As you can see, the Length of the fur
is interpolated over the surface of the image.
Add another Key and place it at the top-middle of the KeyMap area. The new Keys value is evaluated where you put the Key, so no major difference should be visable till you change the length at this new Key.
All Channels works like this, except the
Color and the Thickness Channels, which needs more parameters.
Color and Thickness
Length, Wave, Gravity, Segments, Density,
Direction and Bend are all 2D-parameters. They vary over the span of the
surface only. Color and Thickness are 3D parameters, as the color of a
hair can change over the span of a surface AND over the length of the hair.
In other words, the color of the hair can be different at different points
of the surface, but it can be different at different positions of each
hair too.
The ColorStrip is used to set the color (Diffuse, Ambient and Specular colors) at different locations of the hair (Root color, middle color, tip color) and the Thickness of the hairs. (Refer the tutorial #2)
To define color in 3D space, each Color
Key is really an instance of a ColorStrip thus the KeyMap in figure 1 really
symbolises a color specification as it's seen in figure 2.
And results in this image:
Color Keying
To do the image in figure 3, first, we
have to delete the Keys already there. Hold Delete (Just over the left-arrow
key) and left-click the Keys 2 and 3.
Now, move Key 1 to the top-right corner
of the KeyMap area, by holding "M" (Move) and click-drag the key.
Notice how the
'normal' moves around on the surface in the graphics-window as you drag
the Key.
In FurDesigner, there's 4 different parameters
that varies over the length of a hair. As in Softimage|3D there's 3 different
color parameters - the Diffuse color, the Ambient color and the Specular
color. Futhermore you can set the thickness of the hair to vary along the
length of the hair.
Parameters that can change over the length
of the hairs are called "Color mode" parameters, even Thickness is a "Color
mode"
First, let's work with Diffuse color.
Depress the "A" for the Length Channel and press "A" for Color. This way any new key added to the KeyMap area will have the Color Channel active.
Make sure color-mode is "Diffuse" - check it over the RGB sliders. If you followed this tutorial corrctly, ColorMode is already set at "Diffuse" - if not, press down "Diffuse"
The Channel selector selects what type
of Channel will be added to the KeyMap area, but a Color Key can be either
a Diffuse, a Ambient, a Specular or a Thickness type.
To see what you are doing, press down the "Color" channel selector. These buttons selects what Channel will be drawn 'behind' the keys in the KeyMap area. To see how the colors are interpolated, press down the "Color" Channel selector.
Press left mouse button on the KeyMap area to add a Color key of type Diffuse. Again, notice that the 'normal' shows you where the key is going to be, on the KeyMap area as you drag the key.
When a Key is selected on the KeyMap area,
you are editing that key's values. If for example a Key don't have the
Length Channel active, and you pull the Length slider, either the global
key is changed (If there's only one key with a active Length Channel) or
you will get a error message telling you to select a Key with a active
Length Channel.
Editing Color Keys
Now you have two Color keys on your KeyMap. To select a key for editing, hold down the "M" Key (Same as when moving keys) and left-click the key. It turns blue and is selected.
Select Key 1 by holding LMB and click Key 1.
Tip: You can select several Keys by holding "T" and click-drag. A Yellow frame will be drawn as you drag, and the keys you frame will be selected. This way Left mouse 'Tags' keys, Middle mouse 'Untags' keys and Right mouse 'Toggle-tags' keys (As in Softimage). If more than one key is selected, all the selected keys will be edited at the same time, when pulling a slider.
Key one has all channels active by default. You can de-activate any channel by selecting the Key and depress the "K" (keyed) for the channel you want to deactivate. If you deactivate all keys of any channel (if you deactivate all the Length Keys for example) a new key will be assigned to Key 1, as you always need at least one instance of any Channel at any time.
If you deactivate all Channels for a given Key, you will be asked if you want to delete the key (as it don't have any function anymore) or leave a 'Phantom' key. A Phantom Key is a KeyPoint with no Channels active. You cn re-activate any channel for a Phantom key at will.
Switching Channels on/off.
Delete all Keys in the KeyMap area by holding
the "Delete" key (on the keybaord) and left-click the key you want to delete.
If a key do not go away, that key probably holds the only instance of some
Channel, and thus this is the 'Global' instance of that Channel. To get
rid of it, select Key 1 and check if any Channels are switched off.
A channel is switched off if the
"K" button for the Channel is not pressed.
To switch on a Channel, just press the
"K" and the Channel is activated for the select(ed) key(s).
To switch off a Channel, just depress
the "K" and the Channel is de-activated for the select(ed) key(s).
Working with multiple keys
In Softimage, do a default b-spline grid. Take it into FurDesigner and add two Length Keys to the grid. (You get to deside where the Keys goes) Make the two keys have different lengths, so you can see the difference.
Notice that Key 1 by default has all channels active, to forfill the prequisition that any Channel should be present at a KeyMap at any time.
Now, select Key 2 (With "M" or "T" on the
keyboard) and switch on the "Color" Channel for that key, by pressing the
"K" button for the Color Channel. Key two now looks like this on the KeyMap:
2-dL
This tells you that
this is key 2 and that the "Diffuse" and "Length" Channels are active for
this key.
Which tells you that all Channels are active for Key 1.
To deactivate a Channel for a Key, select the Key and depress the "K" button.