About FiberMesh™

ZBrush 4R2b brings a new specialized mesh generation tool: FiberMesh™. You may already be familiar with the Fiber material from previous versions of ZBrush. FiberMesh is different because it is not a render process. Instead, FiberMesh creates real geometry on the fly which is added to the existing model as a new SubTool.

You will find FiberMesh in the Tool >> Fibers sub-palette.

Depending on your settings within the Fibers sub-palette, you can generate totally different shapes for fibers, hair, fur and even vegetation. Thanks to these fibers being a real geometry, you then have the ability to sculpt your hairs with ZBrush’s powerful feature set. This includes the default sculpting brushes, Masks, TransPose, etc. as well as being able to paint them through the PolyPaint system. ZBrush 4R2b also introduces a number of “Groom” brushes designed specifically for use with the FiberMesh feature.

Of course, because these fibers are real geometry, they are also able to be exported to your application of your choice. Export the fiber geometry with or without UVs where each fiber will allow a texture to be applied to the individual fibers.

FiberMesh geometry is optimized for performance which and includes specific attributes which let thethat allows the ZBrush groom sculpting brushes know that they are being used on a FiberMesh. Any 3D brush can be adjusted to edit fibers with new settings available in the Brush Palette. However, if you do something that changes the topology -- like slicing the fibers or adding subdivision levels – ZBrush converts the FiberMesh into a classic PolyMesh3D. From that point forward, the sculpting brushes will behave exactly like they would for any normal mesh object.

FiberMesh™ Workflow

Fibers must be generated on a mesh surface. They cannot simply be created out of empty space. Before generating your fibers, you must prepare the model that the fibers will be grown from. There are two main elements to this and of course, the Fibers settings:

PolyPaint the source model with the colors of your choice. When the fibers are generated, they will (depending on the Fibers settings) draw their coloration from that of the underlying surface.

Note: The fibers can only use PolyPaint information. They cannot use the color information from a texture. You would need to convert your texture to PolyPaint to use it for FiberMesh color information.

Draw a Mask to define where you wish to have your fibers grow from on the model. The intensity of the Mask will modulate the density and the length of the fibers. It is advised to change the Mask intensity by modifying the RGB Intensity of the Mask brush and/or by blurring your Mask after it has been drawn. Lower intensity will create a less dense area of fibers with a short length. At full Mask intensity the fibers will take on the full attributes defined in the Tool >> Fibers sub-palette.

Note:When modifying a Mask brush setting, you must hold down the CTRL key while changing its setting. Otherwise, you will affect the current sculpting brush settings instead of the Mask brush.

For better fibers distribution and overall best results, it is recommended to generate your model’s fibers in several passes. This will let you have better control over the results than if you try to generate all your fibers at once.

Once the surface’s PolyPaint and Mask have been defined, modify the Fibers settings according to the style you are looking for. Now press the Preview button. Your fibers will appear as a non-editable preview. At this stage, if you move your point of view or orientation of the model, the fibers will disappear until you release your mouse cursor. While in Preview mode, changing any of the Fibers settings will instantaneously update the fibers on your model without the need to cancel your operation and start from scratch.
To evaluate your Fiber with complete shading, press the BPR button at the top right of the interface or use the Shift+R hotkey. This will render your FiberMesh so that you can be sure you’re happy with the results before proceeding to the sculpting and styling phase. Picking the right Material is also a key factor in your FiberMesh render.
Once you are satisfied with your results, press the Accept button to generate your FiberMesh as a new SubTool.
You may now repeat the above steps with a different Masked area or different settings. In this way, a single surface can have many different types of Fibers effects.

Note: 3D brushes cannot be used on the preview fibers. You must click the Accept button in order to use any 3D brush with the FiberMesh feature. When Accept is pressed ZBrush will create a new FiberMesh SubTool that is ready for sculpting and detailing.

An example of using a texture-based Mask a PolyPaint to generate colorful fibers.

Once your fibers have been generated, select the resulting SubTool in the Tool >> SubTool sub-palette. You may now start using the different sculpting brushes to alter the fibers, including their colors.
ZBrush 4R2b includes a wide variety of predefined Groom brushes dedicated to FiberMesh sculpting. These allow you to style the FiberMesh to the exact form and aspect that you wish. New settings have also been added to the Brush Palette for these brushes. (See the New Brushes section of this document.)
In addition, all traditional sculpting brushes like Inflate, Pinch, Soft Concrete, Nudge (with the Picker set to Once Origin) and Move can be used to produce interesting results. Be aware that as these brushes were not designed specifically for use with Fibers, they can affect the shape of the fibers and the deformation can become extreme.
To restore your fibers to their default width or length (but not position) you can use the new Tool >> Morph Target >> Morph width slider and Tool >> Morph Target >> Morph length slider. Please refer to this document’s Morph Target section for more information.
As with a traditional PolyMesh 3D, you can use the Mask brushes to protect certain fibers. A unique feature when Masking fibers is that when the Mask is painted on any portion of a fiber, ZBrush will Mask off the fiber’s entire length.

FiberMesh™ menu settings

FibersMesh fibers are composed of several settings which affect their shape, form and distribution. Most settings have an additional “variation” slider which will add some randomness to the corresponding setting in order to avoid a “too perfect” look in your fibers.

The FiberMesh menu in the Tool palette

Preview: By clicking on the Preview button, ZBrush will generate a temporary FiberMesh based on the current settings, explained below. While in this state you can change your Fibers settings and see the results updated in real-time. You may also generate a render with BPR to evaluate your final result. While Preview is active, rotating or moving the model will temporarily hide the fibers until you release the mouse button. Changing your support model’s topology, Masking or PolyPainting information will disable the Preview. The fibers will disappear until you press Preview again. To completely turn off the fibers that are being displayed click on Preview again.

Accept: Generates the FiberMesh as a SubTool of to the support mesh. At this stage, the fibers will become a SubTool which may now be sculpted, styled and painted. Except for the BPR render options for fibers all other The Fibers sub-palette settings will not affect a FiberMesh once it has been converted to a SubTool. These settings only work in Preview mode.

Max Fibers: Defines the maximum number of fibers generated. ZBrush will populate your model based on the other settings below. Values are in thousands of fibers.

Note: A human head typically has between 80,000 and 140,000 hairs, depending on hair color, thickness and baldness.

By Mask: Defines how strongly the Mask influences where fibers are to be created. The higher this slider, the more ZBrush will use the Mask as a guide to populateing fibers. If there is a less intense Mask on your surface then ZBrush will populate fewer fibers with a shorter length. This slider’s effect is also calculated with the By Area slider so that the two sliders complement each other.

By Area: Defines the fibers based on the underlining mesh topology. Fibers on large polygons will be longer and thicker than fibers on smaller polygons. This feature is important because it also considers the shape of the FiberMesh support surface and produces more natural fibers on models with orientation variations and breaks in the shape.

Imbed: Defines if the root of the fiber will be directly on the underlying surface, hovering right above the underlying surface or imbedded deeper into the surface. This latter result is useful if you create your fibers on a low resolution surface and later will be subdividing the support mesh (causing it to contract slightly). Imbedding the fibers will ensure that they remain “attached” to the surface rather than end up floating above it.

Length: Defines the overall length of the fibers. The individual length of each fiber is then modulated by the Mask intensity and the By Area slider settings. Coverage: Increases or decreases the density width of the Fibers.

Flare: Locally increases or decreases the width of the each Fiber so that it has a wider tip or root. The position of the Flare is determined by Flare Center (below).

Flare Center: Defines the location of the Flare on the individual fibers. A positive value will increase the size of the tip while a negative value increases the size of the fiber’s root.

Flare Exponential: Defines how the Flare progresses along the segments making up the length of the Fiber. A low value will define a fast progression of the Flare while a higher value will Flare progress more gradually along a greater portion of the fiber’s length.

Scale Root and Scale Tip: Adjust the scale of the corresponding part of the fiber. These settings can be combined with the Flare settings above, giving you more control over the shape of the fibers. Slim: Defines the ratio between the width and height of the fiber section. Negative values flatten the fiber’s width while positive values flatten its depth. Twist: Applies a twist effect to each individual fiber.

Note: The Twist setting gives a better specular look when combined with the Anisotropic settings. When using Fibers to create hair, it’s advised to use a little bit of Twist when possible to improve the visual appearance.

Gravity: Causes the ends of the fibers to droop. The direction of the gravity is controlled by position of the model relative to the canvas’ working plane. For example, if you loaded the DemoHead.ZTL facing down with the top of his toward the camera the fibers direction will be dropping toward the front of the face.

Note: It’s important to first set your model’s orientation before setting or updating the Gravity value.

Horizontal and Vertical Tangent: Alters the direction of the fiber by changing the Normal value of the support mesh in a vertical or horizontal direction. These settings are primarily used for generating fibers on top of a FiberMesh SubTool. Both settings can be helpful to create feather-like fibers by combining a fiber on the top of an existing FiberMesh. As this setting uses the polygon and the vertex order of the support mesh, it works better with FiberMesh objects than on normal meshes.

Clumps: Attracts the tips of fibers together when grown from the same support polygon. Moving this slider to a negative value will separate the tips more such as with hair plugs.

Base Color: Colors the base of the fibers using the color selected in the corresponding color patch to the slider’s left.

Tip Color: Colors the tip of the fibers using the color selected in the corresponding color patch to the slider’s left.

Morph Target Guided: Generates Fibers by comparing the current state of your tool to a previously stored morph target.

1. Select your Tool or SubTool.

2. Store the Morph Target by clicking on Tool >> Morph Target >> StoreMT.

3. Create sculptural change.

4. Click Tool >> Morph Target >> Switch.

5. Activate the FiberMesh Preview using Tool >> FiberMesh >> Preview.

6. Click the Morph Target Guided button. ZBrush will generate Fibers by calculating

the difference between your model’s current state and the Morph Target.

The Morph Target Guided function in action

Profile: Defines the number of sides for each fiber. The default value is 1 which will create a strip of one sided flat polygon(s). Increasing the value to 3 or 4 will create a triangle shaped fiber that is capped off at the end. Increasing this value to higher numbers will create rounded fiber sections, but it will also drastically increase the FiberMesh polygon count.

When the value is adjusted higher than 1, ZBrush will warn you that you can alternately use the BPR Sides setting located in the Fibers sub-palette to increase the number of sides at render time rather than having to work with a high number of polygons during sculpting. We recommend keeping this value at 1 and use the BPR Render options when creating fibers that are intended for hair, fur, fabrics for clothing, and etc. Only use Profile when you’re going to be exporting your FiberMesh.

Segments: Defines the number of segments along each fiber’s length. (Number of polygons per fiber per side.) A high value will create smoother angles but will also increase the total polygon count.

Fast Preview: This allows you to modify and sculpt the fibers with more ease as ZBrush will only display the overall shape of the each fiber.

Note: Some settings like Flaring are not visible when in Fast Preview mode.

The Fast preview mode isn’t restricted to the current Fiber preview, but to the selected FiberMesh SubTool after its creation.

Preview Fiber Visibility (PRE Vis): Defines the number in percentage of fibers to display when the Fast Preview mode is enabled. Root and Tip Anisotropic: The Anisotropic value affects the surface normal of the root of the fiber or its tip. Increasing the values will producing a more natural looking fibers. When these values are raised the normals of the fiber will follow the path which allows the normals to lay flat on top of each other.

Note: Some settings like Flaring are not visible when in Fast Preview mode.

Unlike other Fibers settings, Fast Preview mode isn’t restricted to the current Fiber preview. It is instead applied to the selected FiberMesh SubTool after creation.

Preview Fiber Visibility (PRE Vis): Defines the percentage of fibers to display when the Fast Preview mode is enabled. This can be used to speed up performance while working with your FiberMesh. Fibers that are invisible due to the Pre Vis value will still be affected by sculpting and painting.

Root and Tip Anisotropic: The Anisotropic value affects the surface normal of the root of the fiber or of its tip. Increasing these values will produce more natural-looking fibers. When these values are increased, the normals of the fiber will follow a path that allows them to lay flat on top of each other.

Note: These settings are different than the material Anisotropic settings as they affect the geometry surface aspect itself. As a result, you don’t need to change this setting in the Material settings. It is important to consider this point as some materials like MatCaps don’t have Anisotropic settings.

Subdivision: Defines the number of times each fiber should be subdivided at render time. This operation subdivides the fiber in the same manner as traditional subdivision smoothing and makes the fibers look more natural.

Sides: Defines the number of sides that each fiber will have when rendered. This setting is only available when the Profile slider value was set to 1 at the time the fibers were created.

Radius: Increases the radius of the fibers when they are rendered, giving them volume without needing to increase the amount of actual geometry.

FiberMesh™ UVs

Once your Fibers have been generated as a FiberMesh it is possible to generate UVs. The same UV map will be assigned to each individual Fiber, allowing you to apply a texture to all of them. This provides additional possibilities for the look and style of your Fibers, especially when using them to create complex plants.

Due to the large amount of memory required for these UVs, this feature isn’t automatic.

Even though it’s the same map for all Fibers, these UVs must still be associated with the individual vertices. When you have hundreds of thousands of Fibers (usually with many polygons each), that can become an exponentially large amount of data!

On the left, the original fibers. In the middle, creating the Fibers UVs and selecting a texture. On the right, the final result.

Follow these steps to create UV’s for your Fibers and apply a texture to them:

1. Create your Fibers. For the memory reasons explained above, try to use a low Max Fiber setting.

2. By default, ZBrush will advise you to use Preview mode. In order to preview textures, however, it is not recommended to use this mode.

3. Once your FiberMesh has been created, select its SubTool.

4. Go to the Tool >> UV Map sub-palette and click on FiberUV to generate the mapping. Your UVs will automatically be “per Fiber” which means that all Fibers will share the same UVs. This button is enabled only when a SubTool composed of Fibers is selected.

Note: If the button is grayed out while having a SubTool composed of Fibers selected in the SubTool sub-palette, it’s because you have modified the Fibers topology and transformed them to a default Polymesh3D. Operations like Slice Curve or applying a subdivision-level transformation to the FiberMesh topology will cause this to happen.

5. In the Tool >> Texture Map sub-palette, select the texture of your choice.

Note: You can use a texture with pure black color to define transparency. The Fibers will be rendered corresponding to this transparency information. Keep in mind, however, that the transparent portions of the Fibers will still cast shadows just as if they didn’t have transparency.

Additional information about FiberMesh™

Some examples of a FiberMesh created with the default settings and then sculpted using different Groom Brushes.

Several brushes are “fiber aware”, which means that they have a dedicated default behavior when used on a FiberMesh. By using a fiber aware brush you ensure that the attributes your Fiber was originally created with will be maintained. The exception is if you use a Groom brush that is designed to alter Fiber parameters such as how the Groom Length brush is meant to lengthen the Fibers.

The Smooth Brush will reduce Fiber size, only affecting its thickness.

The Mask brushes work on the full Fiber and propagate along it. It’s is helpful to protect groups of Fibers to shape them more accurately or even simply PolyPainting them.

Each “classic” sculpting brush can become “fiber aware” by enabling the settings located in the Brush >> FiberMesh sub-palette. Please refer to the corresponding chapter for more information about these settings. For your most common needs when modifying Fibers, simply use the Groom series of brushes as they were designed specifically to work with Fibers.

Note: The Groom brushes are mainly traditional brushes with Brush >> FiberMesh settings enabled.

When Fibers are created and accepted, ZBrush stores a Morph Target. This allows you to use the various Morph settings to alter or revert your fibers. It also allows you to use the Morph brush to selectively revert the sculpting on your Fiber shapes.

When Solo mode is enabled ZBrush will only display the FiberMesh together with its underlying support surface. When a FiberMesh preview is accepted, the created SubTool will be inserted just below the supported mesh SubTool rather than at the bottom of the SubTool list.