Tutorial: Zbrush – Materials and Polypaint
Materials are applied to objects to help define how they will be rendered beyond mere colour data – will they be shiny or reflective? Transparent etc.
Materials can be accessed by clicking on the materials button in the toolbar, and picking from the list. Click on a material to apply it to your active tool and it’s subtools.
To ‘lock’ a mesh to a particular material, so that it doesn’t change every time you select a new one, or to apply a material to an individual subtool, set your brush mode to ‘MRgb’ or just ‘M’, choose your desired material, then choose Colour > FillObject from the top taskbar.
Materials are added on a per-polygon basis, so you can paint different materials on the same mesh.
Different materials have different properties – some are better suited to skin, machinery etc based on their specular, reflective settings etc.
You can adjust a material’s appearance by clicking Materials > Modifiers in the top taskbar and adjustig the sliders.
Polypaint is the process of adding a texture to your material by painting the colours on directly with a brush. The texture can then be unwrapped afterwards into a Traditional UV Texture. This method is much more intuitive for artists compared to the reverse which is normally employed by other 3D software.
There isn’t too much you need to learn before starting Polypainting, but it will require skill to paint great textures.
Setting a flat base
To set a neutral base for your model, choose a material you want to use, and a default colour from the toolbar on the left. Go up to Colour in the top taskbar and select FillObject.
Make sure mode is set to RGB, so that material is not affected, And that the ZAdd and ZSub buttons are unselected, so as not to continue sculpting whilst painting.
Choose your brush stroke style to determine how you want your paint to be applied, and add an alpha to change the shape of the brush. For example the image of the toolbar below has the brush set to colour spray mode, so instead of a single continuos line being drawn, a speckle of dots will be drawn whilst the button is held. The alpha determines the shape of each individual dot – this particular setting is good for creating skin textures as it can quickly recreate the faint mottled colour variations found in skin.
Hold Shift to blend the edges of your paint together.
The RGB Intensity slider affects the opacity of your brush stroke. Set it to light values to add in subtle hues and details.
A cool addition to your textures is the ability to add decals straight onto the mesh – for instance tattoos on skin or labels on machinery.
First, create your decal design in a software like photoshop.
For simple monochrome decals all you have to do is set the alpha of your brush to your design then drag it onto your mesh in the desired colour.
The alpha should be a square, greyscale .png file.
To import your alpha, either go to Alphas > Import in the top taskbar, or open the alphas panel in the brush toolbar and click the Import button at the bottom.
For multicoloured decals the process is a little different:
Create your decal as before, then create an alpha brush consisting of the silhouette of the entire decal in white, and everything else black.
In the alphas section of your brush toolbar, import the alpha. Then, in the Texture section below, import the full colour version of your alpha.
As the image below shows, with Brush Stroke mode set to Drag-Rect, and your alpha and decal texture imported and set, you can quickly add these details to your mesh.