Tutorial: Using Colorized Spray

From ZBrush Info

Polypainting Example

Let's look at polypainting in action.

Set Up a Model

You'll need to set up a model. Below, we've brought in a head model (of a few million polygons), and filled it with a good base color on which to paint skin details. Our model is broken into subtools (head and eyes/teeth), so we can set things up so that painting affects only the head. You can find out more about subtools in the appropriate section of the documentation.

In more detail, we've set up our model and environment as follows:

The model is about four million polygons--about right for the 2048x2048 texture map we're going to generate. In general, the number of polygons in your model should be approximately equal to the number of pixels in your final texture map. Limits on this will depend on your system.

On with the tutorial.

1. Make sure that Transform:Edit and Transform:Draw are both on, so you'll be in normal sculpting mode.

2. Ensure ZAdd and ZSub are both off. Since we're just creating a texture, we don't want to affect its geometry.

3. Turn on Tool:Texture:Disable UV, to prevent textures from inadvertently being applied to the model during the polypainting.

Note: Disabling UVs has another major benefit. Without UVs, your model will occupy significantly less memory space. This might provide increased speed, or the ability to perform another level of subdivision, or both. It's much better to use this method than to simply set the texture to 'Texture Off'.

4. Turn Tool:Texture:Colorize on to enable colorization of individual polygons.

5. Choose as the primary color a shade to use as the base skin color, and press Color:Fill Object. This colors every polygon in the model with the current primary color.

Texturing the Model

It's time to start painting the model's polygons. We'll begin by using a trick that make-up effects artists have used for years. Use the Colorized Spray stroke with a low Color Variation to simulate the use of an airbrush at low pressure.

To do this:

1. Select alpha Brush 25 to provide an irregular dark/white pattern to our texturing. Other alphas could also work.

2. Choose the Stroke:Colorized Spray stroke, and set Stroke:Color to a low value. This last setting is actually the color variance setting. Together, this stroke and the color variance setting will create a spray with subtly different shades of the selected primary color.

3. Paint, adjusting the brush size as appropriate to the area you are painting and the effect you wish to achieve.

4. With that layer completed, the skin is already looking much more realistic:

5. Of course, you can continue painting as you like, using different colors, alphas, stroke types, and other options.

Time for Hair

The hair looks much different, but creating it is just a matter of selecting the appropriate strokes, tools, etc., and continuing to paint the model. In this case, a dark brown color, the Brush 07 alpha, and the Dots stroke type.

Working in Projection Master

The edges of the hair from the previous step are rough and unrealistic in appearance, due to the coarseness of the stroke used. It would be possible to fix that using additional polypainting, but it's quicker and simpler to just drop into Projection Master, and use the additional selection of brushes there.

1. Press g to enter Projection Master. The model is dropped to the canvas; you won't be able to rotate it until you exit Projection Master
2. Select the Tool:Smudge tool, and a small brush size.
3. Paint with strokes in the direction of hair flow, to smooth the hair edges as shown below.
4. Press g again to exit Projection Master.
5. Rotate the model and repeat the above steps as necessary to paint the entire hairline.

Assign UV Coordinates

Our model started without UV coordinates, so it's time to assign them. To do this:

1. Set Tool:Geometry:SDiv to 1, the lowest subdivision level of the model. Your model should appear similar to the figure shown.

2. Press Tool:Texture:AUVTiles. ZBrush will automatically assign UV coordinates according to an internal algorithm that will evenly distribute detail over a texture map.

Create the Texture Map

Everything is else is done, so it's time to create the texture map.

1. Set Texture:Width and Texture:Height to the desired dimensions of your final texture map. Width and height values that are powers of two work best.

2. Press Texture:New. A new texture filled with the current primary color will be created, and will appear to overwrite your polypainting. This occurs simply because a selected texture will override polygon colorization when a model is being displayed. Your polypainting is still there, it's just hidden by the newly created texture (as shown in the image).

3. Set your subdivision level to its highest setting.

4. Finally, press Tool:Texture:ColTex. This will transfer polygon colorization to the newly created texture map. You'll see this reflected in the texture map's thumbnail, which will appear similar to what is shown to the left.

Note...Your current "RGB Intensity" value will determine how much of the polypaint color intensity is actually applied to the texture map when you press the "Col>Tex" button. For example an "RGB Intensity" value of 100 will transfer all of the color intensity to the texture map, while an "RGB Intensity" value of 50 would transfer half the color intensity.

Finished!