Hair modeling beginner tutorial

There are multiple textures with similar density, this will introduce a bit of diversity and randomness. Hair tool is able to randomly distribute select UV boxes to a selection of cards, using UV tools which will be described later.

Why not just use a ton of lower density textures? It is certainly an option, but poly count can get quite high with such an approach. With a proper layer structure and optimization, hair meshes can consist of as little as 3000 vertices. Most of Cyberpunk 2077's meshes have 10-20k vertices.

Increase subdivision steps to 4. This affects the 'virtual' curve's subdivision, but it will not affect the final poly count. If you need more points near the roots, use the Slide Points deformer. Change Uniform factor to change the distribution of curves across the sharp edge.

An incredibly usefull deformer. Aligns the tilt of the curve to the source surface. Enable twist fix if the curve is twisting in unexpected ways.

Mirror deformer will create a symmetric copy around the origin of the object, unless a different target is specified. For now, the symmetry is perfect (which is not desired), but that will be fixed later. The order of deformers matters. They work from top to bottom, just like modifiers. You can think of them as such.

You may have noticed already, that if you go into edit mode on the curves object we are working on, you are seemingly unable to interact with the individual curves. They are still 'virtual', sometimes referred to as 'fake'. That's because they are fully procedurally generated from the grid surface. Procedural workflows have a ton of advantages, you can change parameters at any time, the primitive geometry is very easy to edit if made correctly." A subsystem or deformer can easily be copied over to a new grid surface or system, making the creation of subsequent hairstyles much faster. A subsystem can be 'baked'. This will create real curves, which you will be able to edit freely in edit mode. However, since subsystems are applied from top to bottom, you can only bake them starting from the top. It is a good practice to leave everything procedural as long as possible. Additionally, make sure to save a backup before baking.

The duplicate deformer will multiply each filtered curve, and distribute the children in a set radius. Make sure to enable Even Thickness to prevent children clipping through eachother if generated on an angled surface. Distribution Shape value is 0 by default. A value closer to 1 will pull the generated curves closer to the parent, and a negative value will push them away toward the circumference of the radius. Here, a value of 0.2 resulted in nice layering toward the tips.

A duplicate deformer is often paired with a Clump deformer. This pulls the duplicated children toward their parent.

Attach to surface deformer will pull the roots of the curves toward the source surface. Make sure to personalize the input values on this deformer, they can vary significantly for each hairstyle. You want to avoid creating patches of clipping, as shown here:

You can mess with the flip seed to achieve a better result for specific strands, if needed. Adding some random tilt can also help greatly when hair like this is viewed from the front (cards are flat from the side, so in certain cases the hair may appear overly thin).

The Noise Deform deformer is incredibly usefull for introducing some randomness to the curves.

Both the random Tilt and Noise Deform deformers should be below the mirror deformer. As stated previously, deformers take effect from top to bottom, so the randomness introduced will not be symmetric.

If you are using HT default material/shader, you can skip this section. If you plan to use a custom shader or textures, read on.

In the Profile menu, you can find 2 input fields, one for the material, one for UV Data.

When selecting a custom shader, this happens:

To fix this issue, copy the HTool_UV node from the HT default material, and plug it into the image nodes in your custom shader.

Now, your UV's will most likely be completely messed up. To fix this, navigate to UV Editing workspace.

Press the Hair UV button in the top-right corner of the UV editor and follow the instructions to set up new UV boxes for your hair.

Then, navigate back to your deformers, where you can find the UV Regions Distribute deformer. Use it to assign UV boxes to the layer.

When you duplicate an object with a hair system, or paste a hair system, or perform the same actions on the profile tab, you are not creating new data blocks. Rather, linking a new object to the same data. Changing a parameter in the hair syste of object 1 will also change system 2, because they share the same data. By simply pressing the [2] (or higher number, if more systems shade data), you can make it unique, and thus independent.

Add the Attach to Surface deformer below the Push Out, but before you start tweaking the input curve.

The Push Out deformer will allow you to create a second layer from the same grid surface. Add a Profile Curve input mask to the Influence Range value of the Push Out deformer. Use the influence range input to finely control how much each part of the curve gets pushed out. You want the curves in this subsystem to be just above the first layer. Make sure to push the roots out above the first layer too!

To create the 4th layer, I used a Set Radius deformer. It allows you to control the width of cards, without needing to make the profile unique.

Hair Tool introduces a whole curve modeling workspace, with a couple unique tools, which greatly facilitate manually editing curves. Documentation: https://joseconseco.github.io/HairTool_3_Documentation/hair_modeling/

These are the deformers I used for the second and third layer of the fringe. Each layer is made from 5 or 6 guide curves with 5 vertices each.

This operation is called Baking Subsystems. You can access it by pressing the 3 dots next to the Sub-Systems menu. Baking will allow you to finish procedural operations manually.

If your strands are not attached to the scalp, and you want them to remain this way, make sure to un-check the attach to surface option in the context menu which appears in the bottom left when baking.

If you are satisfied with the procedural result, you don't need to bake it.

Make sure to apply the subdivision surface modifier to your grid surface before baking subsystems.

It is a good practice to backup a procedural copy of the object before baking.

If you want to add deformers again after baking, you can simply add a new filter subsystem.

If you would like to finish layer 2 (where we had 2 subsystems, one guide curve generator, one curve duplicator), you can bake only the first subsystem. This will only convert the curves from the first subsystem to real instances, making it much easier to edit. I'm baking layer 3 and 4, which do not use Duplicate strands deformers, so I can simply bake all subsystems.