Know the Basics: ZBrush – part four: FiberMesh and UVs
Ricardo Manso teaches the must-know basics for any beginner starting ZBrush. In part four he shows you how to create a FiberMesh and UVs...
Welcome to part four of the Know the Basics: ZBrush tutorial series. To get a more realistic look, we can use FiberMesh to create hair for the character. If we want to render the model outside of ZBrush we can use FiberMesh as a guide to do the hair in other package, we will also need to create UVs so we get the best shape and texture. You can buy ZBrush from the Pixologic website.
Step 01: FiberMesh
FiberMesh is the tool we use to create realistic hair and fur in ZBrush. You only need to create a mask in the area that you want to cover it with fibers. For this kind of character, you can do it with just one mask. It will only generate one area of hair in one SubTool; or you can do it with different masks, repeating the process several times to get different areas of hair separated into different SubTools. This will be helpful when you come to comb the fibers. Once you have your mask go to Tool > FiberMesh > Preview ZBrush will create the fibers in that area, but it is not permanent until you click in accept; but before you do that you need to adjust the parameters.
Step 02: FiberMesh - Modifiers
There are lots of different ways you can set the parameters to adjust the generation of fibers, the best way to learn this is by experimenting and finding the settings that are right for your character. For George you will need to use: Max Fibers - this will give you the density you need to create a realistic head of hair; Length - this adjusts the length, as well as the overall coverage and thickness of each fiber; Gravity - this is helps towards the direction of the hair and also adds a realistic droop at the ends, although if you brush the fibers the effect will be destroyed. To color the hair you can paint it later or use a color patch.
There are two more parameters that are quite important. Profile defines how many faces each fiber has - set it to one which will generate thin, flat fibers, and also keep the render time down. The other parameter is Segments, this defines the smoothness of the hair, the higher the value the smoother the fiber; although, this also increase the polygon count.
Step 03: Brush the hair
Once you are happy with the parameter setting, just click Accept and ZBrush will generate a SubTool with the fibers as shown in the preview. Now you just need just need to create a hairstyle for your character, there are special groom brushes you can use to help you with this. Each of these brushes has a specific function depending on how you want to style your hair. You can mask fibers that you do not want to brush and even hide it; simply make a mask of the area and polygroup the mask, then press Ctrl+W to hide it. You can also change the length of the hair, to shorten them hold down Shift as you pass over the fiber and to lengthen use the GroomLengthen brush. You can also use other brushes such as the Move or MoveElastic brushes, just make sure to go Brush > FiberMesh > Preserve Length and push the slider to 100%, otherwise it will destroy the thickness and length.
Step 04: Exporting curves
After you have the hairstyle defined, you can export the fibers as curves to work on the hairstyle in different software. Go to Fibermesh > Export Curves. If you do not need all the curves you can export whatever proportion you need. Before exporting the curves, go to Fibermesh > Preview and in Preview you can chose the percentage you want. When exporting the curves you can choose the file type depending of the software where you will import it.
Step 05: UVs
The UVs are quite important if you want to export the geometry to other software. They allow you to export different maps and it can reproduce all kind of information. A UV map is like a flattened (unwrapped) 2D shell (skin) of your 3D mesh. You need to create a UV map for each geometry that you want to export. For that you need to go to ZPlugin > UV Master. You should work in a clone of your geometry, click on Work on Clone and ZBrush will duplicate this SubTool with no subdivision. You can create UVs in different ways; using Unwrap straight away creates a UV map, but this is not always the best option. You might want to decide for yourself where to cut so you have a clean map - you can use the polygroups to help you. Make a polygroup for each part, then enable Polygroup and press Unwrap. To see the map looks just click on Flatten and the geometry will unfold. If needed, you can adjust it with the brushes and then UnFlatten it.
UV Master settings
Using polygroups to spate UVs
Step 06: Enable control painting
Another way to control where the UV will be cut is to use Enable Control Painting. You can paint where you want a cut and where you do not want a cut. Go to ZPlugin > UV Master > Enable Control Painting and select Protect. This automatically selects the red color and you can use the Standard brush to paint the areas that you want to protect from cuts. The opposite is enabling Attract - this selects blue - and you paint where you want to make cuts.
If you want to erase what you have painted so far, you simply click on Erase. After you paint the areas that you want to protect and the those you want to cut just press Unwrap and ZBrush will create a map. Sometimes you have to try several times to get what it how you want it. When you have the UV map just copy it, select the original geometry and then press Paste UV. Now your geometry is saved as a UV map and you can use it in a range of different ways and software programs which we will look at in part five.