Stencil Palette
From ZBrush Info
Contents |
Basics: Using the Stencil
The ZBrush Stencil behaves like the drawing tool we are all familiar with. Position the stencil and paint or model around and through it. Use the default “French Curve” stencil or use a custom shape.
Here’s how:
- Open the Stencil palette and activate the stencil by turning on Stencil On. The default “French Curve” stencil will appear.
- Re-size and position using the StencilCoinController. This is discussed in detail a bit later on.
- Paint or sculpt with the stencil active. Areas masked by the stencil will not be affected. Areas partially masked (if using a stencil with grayscale) will be partially affected.
Like alphas, stencils are sensitive to gray values, i.e. a region with 50% gray values permits painting and sculpting at 50% intensity. Stencils are really quite similar to masking using Alphas, but may be more convenient for some tasks. For example, alphas can't be rotated; you need to rotated the model to achieve a specific orientation for a model. Stencils can be rotated. There are other differences as well.
You can create a stencil from the currently selected alpha by pressing the Alpha:Make ST button on the Alpha Palette.
Positioning the Stencil
To position the stencil, hold down the Space bar. The Coin Controller will appear.
By clicking and dragging on various parts of the Coin Controller you can position it in various ways, as detailed below. As might be expected, you can move, scale, or rotate the stencil, but there are some variations and options that require a bit of explanation.
- Clicking and dragging the light gray areas of the controller will move, scale, or rotate the stencil. The top light gray area, which combines moving and rotating, will be explained in a bit.
- Within some of the light gray areas are smaller dark gray areas. Clicking and dragging on these performs the operation of the light gray area in which they are contained, but with some extra constraints.
Positioning, and the Stencil Coordinate System
Any stencil exists on a plane, but is (partially) a 3D object; it can be rotated in three dimensions (but not moved in the global Z dimension; a stencil is always "on top" of whatever it is masking). Because a stencial can be rotated in three dimensions, we need to be cognizant of both global and local stencil coordinates
Rotating a Stencil
Rotating a stencil can be done in one of three ways. The stencil can be rotated freely, about the canvas normal, or about the stencil normal. These last two are equivalent only when the plane of the stencil is in the same plane as the canvas.
To rotate the stencil freely, click and drag on the light gray area of the Rot portion of the coin controller. To rotate it about its own normal, click and drag on the z area in the Rot area, and to rotate about the normal of the plane of the canvas, click and drag on the s area in the Rot area.
Scaling a Stencil
A stencil is always scaled in its own (local) plane. Clicking and draggin in the light gray area of the Scl part of the coin controller scales the stencil in both horizontal and vertical directions. H and V constrain the scaling to horizontal or vertical scaling, in the stencil's local coordinate system.
Moving a Stencil
There are two ways to move a stencil. Clicking and dragging on the Mov area of the coin controller moves the stencil in the plane of the canvas.
Clicking and draggin in the Mov Rot area moves the stencil in the same way, but in addition rotates the stencil so the plane of the stencil at its center point is the same as the plane of whatever on the canvas is under the stencil's center point. Effectively, this sort of 'wraps' the area of the stencil close to its center around the 3D shape under the stencil's center. It's difficult to explain verbally, but if you try it, you'll immediately see what is happening.
Stencil Palette Controls
Stencil On: Activates the stencil feature.
Invr: Inverts the properties of the stencil. Open areas become closed. Closed areas become open.
Interactive: Enables the StencilCoinController. See “The StencilCoinController” on page 203.
Stretch: Scales the stencil to fit the canvas area
Actual: Returns the stencil to actual size.
Horiz: Proportionally scaled to fit the horizontal size of the canvas.
Vert: Proportionally scaled to fit the vertical size of the canvas.
Wrap Mode: Fits the stencil to the underlying object topography.
Res: Higher values produce a more accurate wrap with a slower interaction speed. Range = 8 to 256. Default = 64.
Smooth: Higher values produce a smoother wrap. Range = 0 to 32. Default = 4.
Show: Shows/hides the stencil without deactivating it.
R: Stencil color control. When used alone, stencil will be red. Can be used in combination with G and B. The RGB modifiers affect the color of the stencil display, only. They do not affect colors applied through the stencil.
G: Stencil color control. When used alone, stencil will be green. Can be used in combination with R and B.
B: Stencil color control. When used alone, stencil will be blue. Can be used in combination with R and G.
E: Elevation mode. Turns off the usual stencil display and shows it as a tonal variation on the surface of the object.
Alpha Repeat: Defines the number of times the current stencil will repeat in the x and y directions. An alpha repeat of 4 gives a grid containing 16 copies of the stencil, etc.
Use Alpha:Make St to convert any alpha to a stencil for use with tiling.
Tiled stencils will be placed edge to edge, allowing you to convert seamlessly tileable alphas to stencils which can be applied over large areas without seams.
