GUIDE CHANNELS

Guides in Ornatrix are used to approximately define the shape of dense hair without having to deal with thousands of strands individually. By default guides contain data such as strand positions, root surface positions, and strand selection. Sometime it is useful to add extra data to each guides to control some miscellaneous hair properties such as clustering, curling, or local dynamics and animation properties of hair.

Channels allow users to append extra data to guides that can be used later on. There are two types of hair channels used by Ornatrix- root and vertex channels.

Root channels hold data per every root (guide strand). Using root channels can save a lot of memory because only one real is stored per root and can also be very effective for controlling things that usually don't vary along strand length (such as hair density and dynamics properties).

Vertex channels hold per-vertex data. What this means is that every knot that defines the shape of every strand will have extra data attached to it per-channel. This can be memory consuming, but it allows you to control anything at any point on the hair model. Vertex channels can be useful to control clustering, frizz, and hair shading.

Using guide channels:

Channels can be made very helpful and even irreplaceable in many places during the process of hair management. On the other hand wasted channels can cause slowdown and improper results when not used properly. To use channels correctly one must first understand the concept and their purpose very well.

Guide channels can be created or removed through edit guides modifier. Furthermore some modifiers allow you to manipulate channels procedurally to achieve some kind of modifier-related goal (for example, thickness channel can be modified by some modifiers to make some strands fill in more space than others). It is important to remember that the first root channel and first guide channel are reserved for internal Ornatrix selection. Therefore these two channels cannot be removed. They can, however, be edited and assigned but remember that Ornatrix can change their state at any time.

Example:

Let us take an example of using a channel to control strand-based clustering of dense hair. Whenever you convert guides to hair, the dense hair model inherits the guides' channels. To determine a channel value for a specific strand/vertex in the dense model Ox will look up the closest guide to that strand and use its value. Therefore you can directly modify the strand clustering by simple changing the guide channel value of a guide strand that dense hair will be later clumped to.

Begin by adding a separate per-root (or per-vertex if you desire) channel to your guides in the edit guides mod. You can rename this channel to "clustering" so it can identified easily later on in the pipeline. Now you can go in and modify the channel value for clustering using a brush or directly from sub-roots or sub-strands channel rollout. Go on and assign this new "clustering" channel to the value map in strand clustering modifier.

Note how when you edit clustering channel in edit guides (if show end result mode is on) you can see clusters changing size dynamically. This is just a small demonstration of what kind of control channels can add to your workflow.

Now imagine that you created this clustering channel and forgot to assign it later on. This is a waste since channel is created, memory for it is allocated, and passed along the pipeline from modifier to modifier. If using vertex-based channels, especially, you might notice some un-needed slow-downs due to wasted channels. The best strategy is to name channels according to their purpose, and organize them consecutively so you know clearly which channel performs which operation.