Draw Palette

From ZBrush Info

1 Using The Draw Palette
2 Controls
3 Channels
4 Resources

Using The Draw Palette

The Draw palette contains controls for modifying the current drawing tool. You can change a tool's size, shape, opacity, how new strokes interact with existing objects and strokes, and other functions.

The Draw palette defines your interaction with the canvas. You can paint depth, color, material either individually or simulateously.

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Controls

Draw Size: Sets the overall size of the brush, scaling it in all three dimensions simultaneously. The current brush size is reflected by the white or red circle attached to the mouse/tablet cursor in the image area. Default = 64. Range = 1 to 128. (maximum can be changed using the Preferences:Draw:Max Brush Size slider).

Note: After you change the Draw Size setting, ZBrush automatically zooms the view in the preview window so that the brush fits in the window. This doesn't affect the brush size.

Focal Shift: Adjusts how fast the brush's effect "falls off" as it approaches the edge of the brush. This is really just a shortcut; for drawing tools it is the same as Focal Shift in Alpha:AlphaAdjust, and when modeling it is the same as Focal Shift in Transform:Edit Curve. Both of those curves can be adjusted manually for more control of brush shape.

RGB Intensity : Sets the intensity of the color applied with the brush or in the current object. Default = 100%. Range = 0% to 100%.

In the illustration below, a 3D cube primitive was added with a high RGB Intensity at the top of the sphere, and a low RGB Intensity at the bottom.

Z Intensity: Sets the intensity of the depth information applied with the brush or in the current object. The lower the Z Intensity setting, the less the existing depth information is impacted by added strokes and objects. Thus, setting Z Intensity to 0% has the same effect as turning off the Z options (see ZAdd / ZSub / ZCut, below). Default = 100%. Range = 0% to 100%.

In the illustration below, a 3D cube primitive was added with a high Z Intensity at the top of the sphere, and a low Z Intensity at the bottom.

MRGB / RGB / M: Sets whether you're drawing with the material and color (MRGB), just the color (RGB), or just the material channel (M).

If you want to affect only the depth information, turn all three options off (click the active item) and use one of the Z options (see next item).

Note: Some materials have color built in, so will change the object color even if you're using the M option.

ZAdd / ZSub / ZCut

Sets whether you're adding to or subtracting from the existing drawing; how you're impacting existing depth information in the image. Only one option can be active at a time.

ZAdd adds pixols to the drawing. This works like a standard Boolean union operation. * ZSub subtracts pixols from the drawing. With a 3D object, any front-facing polygons in front of the active 3D object do not display.
ZCut subtracts pixols from the drawing. With a 3D object, front-facing polygons in front of the active 3D object do display.

Note: When painting, think of ZAdd and ZSub simply as add and subtract operations; you don't need to use the more compute-intensive ZCut at all. However, when working with 3D objects, you should generally use ZCut for subtraction operations. Read on for further explanation of the differences between ZSub and ZCut. Alternatively, with no Z option on (click the active button to turn it off), you can paint without impacting the depth information at all.

Sphere painted with ZAdd (left side), ZCut (right ), and Z options off (bottom)

The effects of the Z settings vary depending on whether you're using a standard brush, such as the Simple brush, or working with a 3D object. If using a standard brush, the Z setting affects brush strokes you make after you change the setting.

If working with an active 3D object, the Z setting affects how the object interacts with the rest of the image. This is primarily where ZSub and ZCut differ: With ZSub, any existing pixols in front of the rearmost pixols placed by the 3D object are removed. With ZCut, however, only pixols within the volume of the 3D object are removed. This is best illustrated graphically:

The following shows the interaction of an active 3D object (the red cylinder) with existing pixols (the yellow sphere) using the various Z modes:

ZAdd (left), Zsub (middle), ZCut (right)

Current Tool Preview: The Current Tool Preview window shows the current drawing tool or object, and reflects the effect of changing the basic tool characteristics in real time. The exception is that, when using a 3D tool, such as Sphere 3D or Cube 3D, this window shows the current object. Thus, when you're using a brush, you can see it in the preview window, but when you're editing a 3D object, you can't.

When you first start ZBrush, the Preview window depicts the Simple brush in its default state. You can rotate the view around the window contents by dragging the mouse inside the window. For example, if you drag a short distance toward the upper right, the window changes to a view from an angle.

Current Tool Preview showing tool headon (left) and from an angle (right).

In the upper-left corner of the preview is a small curved-arrow icon. Clicking this icon toggles continuous rotation of the window view. While the continuous rotation option is active, you can change the direction and speed of the rotation by dragging inside the window. Also, you can temporarily halt the rotation by clicking in the window. At any time, click the curved-arrow icon to return to the default, head-on view of the tool.

In the upper-right corner is a small + icon. Clicking this icon toggles display of the plane used to show the position of the drawing tool relative to the surface; that is, the effect of the Draw:Imbed setting.

Width: Sets the width of the brush. By default, Width is set to 100%; reducing it produces a brush that's higher than it is wide. Range = 0% to 100%.

Sphere brush with Width set to 40% (left), and with Height set to 30% (right).

Height: Sets the height of the brush. By default, Height is set to 100%; reducing it produces a brush that's wider than it is high. Range = 0% to 100%.

Note: When adding a 3D object, you can control its width and height interactively. First drag in one direction to set the object's overall size, and then, without releasing the mouse button, drag in the opposite direction to decrease the width and height simultaneously.

Depth: Sets the size of the brush on the in-out axis. By default, Depth is set to 1.00. Reducing it gives a shallow brush, while increasing it produces a deep brush. Range = 0.00 to 10.00.

Sphere brush with Depth set to .61 (left) and with Depth set to 2.24 (right).

Note: To best see the results of changing the Depth setting, first drag the mouse a short distance in the preview window so that you're viewing it from a slight angle.

Imbed: Sets the position of the brush or object relative to the surface being drawn on. Reducing the Imbed setting moves the brush farther above the drawing surface, while increasing it moves the brush lower in relation to the drawing surface. The position at which the brush intersects the plane in the preview window indicates where the brush will intersect the drawing surface. Range = -2.00 to 2.00.

Note: To best see the results of changing the Imbed setting, first drag the mouse a short distance in the preview window so that you're viewing it from a slight angle. Also, make sure the plane is visible in the preview window; if not, click the + icon in the window's upper-right corner. The plane represents the position of the drawing surface. For example, a Cylinder 3D object is set by default so that its center intersects the object it's drawn on, as shown in this image:

Cylinder 3D object with Imbed set to .00 (left) and with Imbed set to -1.00 (right).

If you want to draw a cylinder sitting on the surface of another object, you need to set Imbed to -1.00, so that its end is above the plane.

The following illustration shows two cylinders with different Imbed settings drawn onto a cube. The cylinder on the cube's top was drawn with Imbed set to .00 (the default), and the cylinder on the cube's side was drawn with Imbed set to -1.00.

Note: By default, a 3D object's pivot point is at its center, and the Imbed setting adds an offset from the center. You can, however, change the location of a 3D object's pivot point using Tool:Deformation:Offset, thus altering the location from which Imbed defines its offset.

Perspective: If Perspective is on, then the model is drawn using perspective, otherwise it is drawn using standard orthographic projection. When perspective is active, the strength of the perspective effect is determined by Draw:FocalLength.

FocalLength: When the Draw:Perspective button is on, the strength of the perspective effect is controlled by this slider. As with camera lenses, a short focal length gives the strongest perspective, and a long focal length the least. However, no magnification takes place.

Top left to bottom right: Model displayed with Perspective off, and then with perspective on and progressively shorter FocalLength settings.

Refract / Blur: It is possible to simulate refractivity of transparent objects through these settings. To use this feature, a 3D object must be drawn with RGB Intensity of less than 100. Refract lets you control how strong the refractive effect is. Higher values result in more refraction. Range = 0 to 100. Default = 0.

Blur lets you determine whether the refractive image is shown clearly through the object or with some blurriness. Range = 0 to 2. Default = 0.

In the image below, a flattened Sphere3D was used as a lens. RGB Intensity was set to 20 and Z Intensity to 80. The GelShaderA material was used. The lower left lens Refract Intensity was at 10. The upper right was at 50. The lower right was at 100 with a Refract Blur of 2.

Note: Only unshaded color is refracted by this feature. If you have color that is created by a material (such as the blue background in the image above) and you wish to have that material-generated color be refracted, you must bake the layer before drawing the refractive object. See Layer:Bake.

Note: Unlike material transparency, Refraction cannot see anything on another layer. It will only refract what is on the currently selected layer. (Transparency is an option available for materials in the Material:Modifiers settings.)

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Channels

Infront / Behind: The controls in the Channels sub-palette provide additional painting, masking, and 3D options, but it's seldom necessary to modify them while creating artwork, as Infront is automatically turned on when you use ZAdd mode and Behind is automatically turned on when you use ZSub mode. These are basically masking operations that determine which pixols of a new object are drawn based on the object's pixol's depths, as compared to the pixols already on the canvas.

There are four possible combinations of Infront and Behind: One on, both on, or neither on. These masking options can take effect when creating an object or in a Edit/Transform mode (Edit, Move, Scale, Rotate).

When Infront and Behind are both off, no masking takes place and new pixols always appear in front of others—new objects always appear on top of previous objects.

When Infront is on and Behind is off, existing pixols can mask newly drawn pixols—new objects are "merged" into the canvas, so their pixols are drawn only if those pixols are closer to the viewer than the current canvas pixols.

When Behind is on and Infront is off, only new object pixols behind existing canvas pixols appear when strokes or objects are drawn to the canvas.

Note: This means that pixols drawn on blank portions of the canvas will not appear, since according to Behind only pixols behind the canvas—the clipping plane—would appear.

When both are on, a new pixol is drawn if it is in front of an existing pixol (including blank canvas pixols) or behind an existing pixol (but a blank canvas pixol will mask it, due to the reason given above.)

The next three items cover all four combinations of Infront and Behind.

Note: In the following illustrations, the cone was drawn first, and the cube was drawn second. Thus, the different options determine how the cone's pixols mask the cube's.

Behind off: Infront off (left) and on (right).

Behind on: Infront off (left) and on (right)

R / G / B: These buttons let you affect which of the red, green, and blue channels are affected by the Infront/Behind settings.

Z Tolerance: Sets the range of depth that a tool can affect, based on the depth at the point you click to begin drawing. When Z Tolerance is set to 0, pixols are masked regardless of depth. For any other value, pixols whose Z-axis distance from the pixol at the starting point is less than or equal to the Z Tolerance setting are affected, while those outside that range are not. The effect also depends on the type of tool being used. Default = 1.00. Range = 0.00 to 10.00.

Mat(erial) Overwrite: Specifies the degree to which the current brush's alpha image (used to control the brush's shape) determines how much of the current material is applied along with the depth information. At lower settings, the material is applied to all of the depth information. At higher settings, however, the material is applied only to the brightest pixols in the alpha image. Default = 2. Range = 0 to 100

For example, in the following image, the Simple Brush with Alpha Brush 30 was applied to the sphere with three different Mat Overwrite settings: 2 (top), 50 (lower left), and 100 (lower right). As the Material Overwrite setting increases, the material is applied to successively fewer of the "lower" pixols produced by the brush. Creative use of this feature can produce endless combinations of bump mapping with materials.