ZBrush FiberMesh and Hair 2 — Questions and Answers
Question 1: Which FiberMesh parameter controls the taper of fiber strands from root to tip?
- Gravity
- Profile (Correct answer)
- Segments
- Twist
Correct answer: Profile
The Profile curve in FiberMesh controls the width profile of strands from root to tip — a tapered profile makes strands wide at the base and narrow at the tip, mimicking real hair strand geometry.
The Profile curve is a graph where the X axis represents position along the strand (root to tip) and the Y axis represents width at that position. A default linear taper creates organic-looking hair. A flat profile creates uniform-width strands useful for grass or bristles. Adjusting this curve is essential for achieving realistic hair rendering when fibers are used as polygon geometry.
Question 2: What does the 'Segments' slider in FiberMesh control?
- The number of UV segments on each fiber's texture
- The number of polygon divisions along the length of each strand, controlling curvature smoothness (Correct answer)
- The number of subdivision levels applied to the base mesh before fiber generation
- The number of groom brush strokes per pass
Correct answer: The number of polygon divisions along the length of each strand, controlling curvature smoothness
Segments controls how many polygon segments (edge loops) each fiber strand has along its length — more segments allow smoother curves and better response to gravity and grooming.
A strand with 2 segments can only bend at one midpoint, creating very stiff, angular curves. A strand with 8 to 12 segments bends smoothly and responds more naturally to GroomCurve and gravity settings. Higher segments increase polygon count significantly — multiplied by MaxFibers, this can produce very heavy geometry. The typical production balance is 4 to 8 segments for grooming and 2 to 4 for export.
Question 3: What does the 'MaxFibers' slider in ZBrush FiberMesh set?
- The maximum length of each individual fiber strand
- An absolute upper limit on the total number of fiber strands generated (Correct answer)
- The maximum number of FiberMesh SubTools allowed
- The maximum number of groom brush strokes tracked in history
Correct answer: An absolute upper limit on the total number of fiber strands generated
MaxFibers sets a hard cap on the total count of fiber strands generated, preventing extremely dense setups from creating unmanageable polygon counts that could slow or crash ZBrush.
Even with high Coverage, ZBrush will not exceed the MaxFibers value. Very dense fur could theoretically demand hundreds of millions of polygons. By capping MaxFibers at 500,000, you ensure workable viewport performance. Production teams often set conservative MaxFibers limits during grooming and increase them only for final export.
Question 4: What does the 'Curl' parameter in FiberMesh do?
- Sets the amount of spiraling or wave applied along the length of fiber strands (Correct answer)
- Controls the strength of the gravity effect on fiber tips
- Sets the angle at which fibers exit the surface
- Controls how tightly fibers cluster together
Correct answer: Sets the amount of spiraling or wave applied along the length of fiber strands
The Curl slider adds a helical spiral or wave pattern along the length of each fiber strand, creating curly hair, wool, ringlets, or coiled grass effects.
Curl works by rotating the strand orientation progressively along its length, creating a helix. At low values it produces gentle waves; at high values it produces tight ringlets. Curl interacts with Segments — you need enough segments to represent the curve smoothly. Combining Curl with Gravity and Length produces realistic curly or wavy hair.
Question 5: What does the GroomPinch brush do to FiberMesh strands?
- It pulls fibers toward the brush center, clustering them into thin, pinched groups (Correct answer)
- It pushes all fibers away from the brush center
- It cuts fibers shorter within the brush area
- It separates overlapping fibers by pushing them apart
Correct answer: It pulls fibers toward the brush center, clustering them into thin, pinched groups
GroomPinch pulls fibers toward the brush center, creating tight clusters or clumps — simulating the way wet or product-laden hair groups together into distinct strand bundles.
Real hair rarely behaves as thousands of individual independent strands — it clumps into bunches due to moisture, oils, and styling products. GroomPinch simulates this by attracting fibers within the brush radius toward its center. Heavy pinching creates dreadlock-like clusters. Used after establishing direction with GroomHairLong, GroomPinch adds the final naturalistic clumping.
Question 6: How can FiberMesh hair guides be exported for use in external grooming applications like Houdini or Maya?
- Export as OBJ — the fiber polygons are automatically recognized as hair guides
- Export as Alembic (.abc) from ZBrush's Export palette with Curves enabled (Correct answer)
- Export as a ZTL file and import using a proprietary bridge plugin
- FiberMesh cannot be exported; it must be re-created externally
Correct answer: Export as Alembic (.abc) from ZBrush's Export palette with Curves enabled
ZBrush can export FiberMesh strand geometry as Alembic (.abc) curves, which is the standard interchange format for hair guides recognized by Houdini, Maya XGen, and other grooming systems.
ZBrush's Alembic export with the Curves option treats each fiber strand as a polyline/curve, which grooming applications interpret as hair guides. Maya XGen, Houdini's Hair tools, and Unreal's Groom system all accept Alembic hair guides. This workflow is standard in VFX production — ZBrush provides the initial groom direction and the DCC application applies final interpolation, simulation, and rendering.
ZBrush FiberMesh and Hair 2
Which FiberMesh parameter controls the taper of fiber strands from root to tip?