Introduction
Presented here are some study notes on creating Strand Based Hair (SBH) using the SBH Editor in Daz Studio.
Some of this information was gleaned empirically, some of it was pilfered directly from various threads on the Daz forums. Let me know if I have left anything out, made something unclear, or if you have any questions.
These notes apply (as of April 2023) only to the SBH Editor that all Daz users have access to, and I do not take into consideration any additional tools that Daz PA’s may be privy to.
Brief History
The SBH Editor was adapted from the old Garibaldi plugin and since 2019 has been included with all installations of Daz Studio by default.
Several updates since 2019 have made the SBH Editor more stable, and it has been complemented by features such as the blended dual lobe shader and NVIDIA iray curves. With that said, given the old architecture and slow rate of improvements, SBH cannot achieve the quality you can get from other industry leading hair tools like Ornitrix, Xgen, or Blender’s new hair tools.
But all the same, if you are frustrated by the quality of available hairstyles for Daz Studio, it may be one of the best options you have.
Use Case
SBH Editor can be used to make hairstyles with high strand density (which will correlate with realism). But there are some limitations.
Can you make morphs and add rigging for SBH with SBH Editor?
No, only PA’s can do this. (We as mere users can only make morphs and rigging for the haircap.)
In addition, only PA’s can create SBH that will scale properly with figure size. This limitation around scaling hair length is related to another limitation, which is that SBH made in SBH Editor must remain unparented from the figure it is fitted to. Such SBH will follow the figure of course, but length may be too long for small characters and too short for large characters due to scale remaining fixed. If someone is able to solve the issue with parenting SBH, then this issue with scale will disappear.
Can you simulate (dforce) hair with SBH Editor?
No, only PA’s can make dforce SBH.
You could technically convert SBH to geometry and add dforce to it, just like you can with any geometry, but this is not recommended for high density meshes like hair.
Can you save and distribute SBH made by SBH Editor?
Yes, but there are limits. See the final section below for saving options.
What are the advantages and disadvantages of SBH Editor?
As alluded to above, the SBH Editor can:
- Create dense hairstyles that, with a lot of effort, can approach realism.
- Can be edited in the SBH Editor by any Daz Studio user, unlike the SBH hair purchased from Daz3d.com, which cannot be edited. This allows for correct fitting of SBH to your custom mesh and combing and reshaping as required
However, compared to a hair system like Xgen, SBH Editor is much more difficult to use because it is lacking some key features, such as:
- Ability to add/delete guide strands as needed
- Tools to easily control and manipulate the flow of guide strands
- More procedural layers to control clumping, noise, and add flyaways
- Ability to visualize other active grooms when editing a groom in SBH Editor
- Ability to use iray preview render while editing
1. Creating SBH Hair
To create a SBH:
- Select the object you want the hairs to grow from
- Click Create>New Strand-Based Hair
Note: A hairstyle may be comprised of just a single SBH item or may be multiple different SBH grooms where each one has been created for different parts of the hairstyle (e.g., one SBH for bangs/fringe, one for back, one for sides, one for sideburns, etc).
Haircaps: It is recommended to create hair on haircaps/scalps rather than, say, a Genesis figure directly as it will give you more flexibility, e.g., ability to transfer the haircap between generations, and ability to easily save the haircap+SBH as a Wearable preset. Note however that you can still save a SBH as a Wearable preset even if it is not on a haircap. See the final section of this guide for instructions on saving SBH.
2. Setup tab
In this tab, you select which surfaces of the object will be involved in the SBH groom. This includes areas that the hairs will grow from, and also those surfaces that you would like to be involved in collisions. For example, if you are creating long hair, you may want to include shoulders so that the hair can be styled against/collide with the body.
Warning: SBH hair can never be fitted or transferred to a different geometry than the one it was created on, so ensure that the geometry/figure/haircap/scalp you are creating the hair on is finalized.
Note: The surface shown in the SBH Editor will reflect the shape and pose of the surface at the time of the SBH creation. To update to the current shape, click “Update Surfaces” button.
3. Paint Tab
In this tab, grayscale maps/masks are painted such that white color will represent areas where the effect is applied 100% and black will represent where there is zero effect, while gray will represent values in-between.
These maps can be plugged into different parameters in the SBH Editor (on the subsequent tabs). E.g., a map can be plugged into the Density parameter to control hair growth (hair will grow on white areas, and will be bald on black areas) or a map can be plugged into the Clumping parameter (white will reflect areas where there is clumping and black where there is no clumping).
Tip: if not already customized, it is best to configure the Daz Studio workspace (Window>Workspace>Customize) such that the viewport ‘orbit’ and ‘pan’ settings are changed to an efficient shortcut. For instance, you could set orbit to use the middle mouse button, pan to use shift+middle mouse (this is one common setup seen in other 3D software like Blender).
4. Distribute Tab
On this tab, hair density and size are set using the parameters.
Very high densities can significantly slow down the viewport in Daz Studio and also lead to longer render time. Finding a balance between density and render time will need to be considered.
Tip: While in the initial stages of blocking out and styling the hair, you can use a lower hair density and large strand-size, then move to using a high density and small strand-size (which will be more realistic) when finalizing the hair for rendering.
The default 0.2mm – 0.1mm thickness is a medium-thick size hair strand, so doubling or tripling this to get a very thick strand could provide a good working size when initially styling the hair. For final render, you may want to create thin strands by going below the default value.
5. Style Tab
In this tab, style curves are adjusted using various tools to create the shape of the overall hairstyle/haircut.
What are style curves and what are interpolated hairs?
‘Style curves’ are spawned at the vertices of the haircap and their shape can be edited by the user to achieve the desired hairstyle. Style curves are effectively guides that control the hair shape, flow, and length. The actual hairs that make up how the SBH looks when rendered will be ‘interpolated hairs’. These interpolated hairs are spawned across the surface between style curves. The density of interpolated hairs is defined by the Distribute tab settings and their shape and length is influenced by the surrounding style curves.
Interpolated hairs will follow nearby style curves, where ‘nearby’ is determined by proximity of the root of the interpolated hair to the root of the style curves. The total influence felt by interpolated hairs, in both their length and shape, will be a combination of all the nearby style curve guide strands (the relative effects of nearby style curves can be tweaked in the Interpolation settings, i.e., Single Guide and Autoparting settings).
Styling the hair: Styling the hair may often be a time-consuming and iterative process, of styling, reassessing, restyling etc. To start with, block out the major shapes and then progressively work toward adding finer details. An example workflow may be the following:
- Scale the hair to roughly the desired length (using either the Scale tool or the Comb tool with ‘Preserve Length’ deselected)
- Change the Segment Length to a small size (this will make smoother, less jagged style curves, and will improve surface collision)
- Use Comb tool (with ‘Preserve Length’ selected) to shape the hair
- Use selection tools to isolate sections of hair, then fine tune, manipulate, and resize with other tools as needed
Parting the hair: Creating a part in the hair can be difficult because interpolated hairs within the parted area will be under the influence of style curves going in completely opposing directions. The interpolated hairs in this region can end up pointing upwards as the adjacent style curves compete for influence of the hair between them. There are two ways to correct this:
- The ‘Autoparting’ and ‘Single Guide’ settings could potentially be used to counteract this problem. Success with creating a part using the ‘Autoparting’ and ‘Single Guide’ settings will depend on the distribution of Style curves on your haircap. Also, be warned that changing these settings from their default may lead to spiky hair glitching, whereupon these settings will need to be restored to defaults to correct the glitch. Another problem with using autoparting or single guide is that Clumping settings can interfere with them and it may be impossible to have both clumping and autoparting/single guide active for a given hair section.
- An alternative approach which removes the problems described above is to split the parted hair into separate SBH grooms, one for each section of parted hair.
Tip: Remember to “save” intermittently. This can be done by clicking ‘Accept’ and then saving the Scene file. You can resume editing SBH under Edit>Object>Strand-Based Hair
6. Clump Tab
In this tab, the basic hair style can be further refined to look more realistic by adding clumping effects.
7. Tweak Tab
On the Tweak tab, a final layer of parameters can be adjusted to introduce randomness, noise, and imperfections to the hair. Much of these parameters (scraggle, frizz, etc) are highly dependent on the segment length of the interpolated hairs, which is a value set under the ‘Interpolation’ section on the Style tab. Therefore, you should reduce the Interpolated Segment Length to a low value (i.e., 0.3, 0.2, 0.1, 0.05 etc.) in order to fully appreciate the effect of the Tweak parameters.
Warning: some of the tweak settings can interfere with the clumping effect, so should be used in full consideration of how it will reduce the effect of clumping. E.g., high values of random root angle will completely destroy any clumping effect.
In other hair systems, like Xgen, you can introduce noise to procedurally create “flyaways” but in SBH Editor such flyaways are usually added and styled manually as separate grooms.
8. SBH Parameter Settings
Important parameters to adjust:
- Render Tessellation sides: this parameter defines the geometry of the hair strands. E.g., value of 3 will convert hair to 3-sided geometry. A value of 1 will convert the hair to iray curves (not geometry).
- Preview PR Hairs: without selecting this option, hair strands will not show up in the viewport.
Iray curves / fibers:
- Set using Render Tessellation Sides value of 1
- Requires Daz Studio version 4.20.1.19 or later
- Renders much faster than geometry/fibermesh hair
- Renders as smooth strand compared to sometimes jagged fiber mesh
- Not appropriate for render engines other than iray (e.g., Filament).
- Reduced options for the blended dual lobe shader (see below section)
- Generally, pros outweigh cons when rendering in Daz Studio Iray.
9. SBH Shader Settings
One of the shaders typically used for SBH hair is the Blended Dual Lobe shader, which is included with the Default Resources. It is also the shader that is applied by default to hairs created in the SBH Editor.
If using Iray curves (Render Tessellation Sides value of 1), this shader’s Transmission Color settings will have no effect. Moreover, the Glossy Layer Weight value must be set to a high value in order for the the root/tip hair color to have any impact.
You can purchase my Gossamer Hair Shader for SBH if you want to have transmission/translucency when using Iray Curves.
Edit (01-Mar-2024): Daz just released Omni Hair shaders for SBH which will also restore transmission/translucency. These shaders use the same principle as my Gossamer Hair Shader.
10. Saving SBH
Important: SBH should always remain unparented from the figure it is fitted to, otherwise the SBH hairs will be additionally transformed whenever the parent object is translated or posed. Of course, the SBH can be parented to a Group or other object so long as that parent Group/object never gets translated/moved. (Please let me know if anyone figures out a workaround for this issue!)
Considerations: You have the option to save the SBH as a figure/prop asset first, or save it is a Wearable preset right away. Technically it is best practice to save assets as figure/prop assets before creating Presets but you should know that there are pros and cons here to weigh up when saving SBH as a figure/prop asset.
Specifically, when saving a Wearable preset without first creating a figure/prop asset for the SBH, the pros and cons are:
- Pro: Any edits made to the SBH after loading the Preset into a Scene file will save with the Scene file. So if a user restyles the hair in the scene file using the SBH Editor, saves, and loads the scene again, the restyling of the hair will be preserved. This is not the case if the SBH is called from a figure/prop asset.
- Con: The SBH geometry will be embedded in the Wearable preset and Scene files, which is not best practice. Usually you would want the preset to merely call the SBH as an asset from its respective folder in the content directory as it increases Scene file size.
Saving Wearable Preset with Haircap: If you have created the SBH on a haircap/scalp, then you have the option to save as a one-click Wearable preset very easily:
- Create a new Group using the default options, and rename the Group to a suitable name for the hairstyle (e.g., “Long Curly Hair”)
- Place the SBH and scalp into the Group
- Select the figure that the scalp is fitted to (e.g., the Genesis figure) in the scene tab
- File>Save as…> Wearable Preset
- In the popup dialog, select the whole Group to save as Preset
Saving Wearable Preset without Haircap: If you have not created the SBH on a separate haircap/scalp, then you can still save as a one-click Wearable preset, but it involves a workaround:
- Create a new Group using the default options, and rename the Group to a suitable name for the hairstyle (e.g., “Long Curly Hair”)
- Place the SBH into the Group
- Place any fitted item into the Group (a fitted item could be a random clothing item, a random hair cap, anatomy, it does not matter so long as it allows you the option to save a Wearable preset in step 5)
- Select the figure that the fitted item and SBH are fitted to (e.g., the Genesis figure) in the scene tab
- File>Save as…> Wearable Preset
- In the popup dialog, select the whole Group to save as your Preset and also deselect the fitted item from step 3.