The Brush & Brush Components

Brush Components - All

Many of 3DCoat’s functions are implemented with a familiar “Brush” interface that both correspond to real world equivalents and also extend the abilities that real world tools of similar nature are capable. Add and remove volume, extrude and imprint detail. Add accurate hard surface features with the control of splines and curves, circles, ellipses and polygons, add realistic media textures and displacements, paint curve-based repetitive elements, precisely position and place relief elements and actual models. Add appendages with freehand flexibility as well as with the precision of adjustable curves. All these things are possible with 3DCoat.


In general, most of the rooms controls function the same, and only vary by the active tool. Let’s look at these common controls, which are primarily for the Paint & Sculpt Rooms.

  • LMB is generally used for most functions, including strokes, activating tools, etc..
  • RMB+Drag up/down with the brush icon over an Object will change the brush size.
  • RMB+Drag left/right with the brush icon over an Object will change the the brush depth.
  • SHIFT+LMB and stroking will perform a smooth operation with almost any tool, in both the Paint & Sculpt Rooms.
  • SHIFT+CTRL+LMB and stroking in the Sculpt Room will apply whatever action you’ve set in the Top Bar (The default is Powerful Smoothing and there are a number of other functions in this drop down list, which are covered in another section of this documentation).

Brush Components

The Brush in 3DCoat consists of many different components combined to make one tool. These parameters are sprinkled in a handful of places, which are discussed in more detail below. The parameters for Brushes consist of these locations and various functions:

  • Alphas
  • Brush Options panel
  • Top Bar
  • Stroke Mode
  • Strips
  • To a lesser degree but still applicable, Materials & Stencils

All of these combined bring together a very powerful Brush Engine, and make it easy to achieve normally difficult paint or sculpting tasks, a whole lot easier. These components can also be saved together, as a single Brush Preset for use later, or to share with your team or anyone else.


Brush Components - Alphas

3DCoat’s Brushes can be given a “profile” by means of the brush Alpha panel.The term Alpha is common amongst 3D sculpting and painting applications wherein the alpha is a simple greyscale image. However in 3DCoat they consist of four painting channels:

  • Color
  • Height/Depth
  • Glossiness
  • Erase Mask

So each Alpha can paint multiple channels at the same time, if you choose to. Making them less an Alpha and more of a multi-channel image brush tip. We maintain the term “alpha” to keep with the industry standard terms.

Alpha Right-Click Options

Brush Components - Alpha RMB

Right clicking on any Alpha will display editing functions for the respective Alpha. Brush Options opens the “Brush Options” panel. Delete Alpha deletes the selected Alpha. Save to PSD/TIF saves the selected Alpha to the chosen format file format to a directory on your computer.

Load from PSD/TIF replaces the alpha that has been right clicked on with another image of your choice, as long as it is PSD or TIF. An Alpha must have 4 layers each corresponding with the four main channels of a brush in 3DC (as noted above, they are Color, Height/Depth, Glossiness & Erase Mask). These channels of the Alpha in detail are:

  • Color: This contains the Brush color as well as its corresponding Transparency mask. This mask affects the Glossiness Layer, as well.
  • Height/Depth effects displacement for sculpting and the height/depth with image based painting. The “zero” height of this Layer corresponds to “middle gray” or (127, 127, 127). Darker values will create valleys and lighter values will create peaks.
  • Glossiness: White represents maximum Glossiness. Black represents absolutely no Glossiness, with shades of gray representing intermediate values. The Color layer of the Alpha’s alpha transparency also determines where Glossiness painting occurs.
  • Erase Mask: This layer is used to create alphas that ignore certain values, in other layers, while painting.

If all the .TIF channels are used, they will all be imported and used according to the table below. If you only use some of the available channels, those you do import will also be used according to the table below.

1 CH: A&H
2 CH: 1 – A 2 –H
3 CH: 1, 2, 3 – RGB, 2 – A, H
4 CH: 1, 2, 3 – RGB, 4 – A, H
5 CH: 1, 2, 3 – RGB, 4 – A, 5 – H
6 CH: 1, 2, 3 – RGB, 4 – A, 5 – H, 6 – Spec
7 CH: 1, 2, 3 – RGB, 4 – A, 5 – H, 6 – Spec, 7 – Erase mask

Edit in external editor: Creates a “live” connection between 3DCoat and the external editor you have specified in the “Preferences” section. The default editor is Photoshop. Selecting this option opens the specified editor and any changes that you make and save from the editor are automatically loaded back into 3DCoat.

Edit as 16 bit TIF: This allows you to save in 16 bit format, rather than 8 bit. Using this option causes the Brush alpha to be saved as a .psd file, allowing it to be reloaded automatically, each time it is edited and saved in the external editor.

–>default (etc.): This option will allow you to copy the Alpha that you right-clicked on, to a folder named in the folder list that you have previously defined. All the folder names you have defined will appear here.

Alpha Panel Drop-Down Menu

Brush Components - Alpha Panel Drop Down

A set of functions allowing you to view and change the current Brush Settings, Add and Create new Brush Folders, Add Brush “Packages” – as well as choose a display size for your Brush Alphas.

  • Refresh Alpha Preview: Refreshes the Alpha icon.
  • Brush Settings: Opens the “Brush Options” panel.
  • Add New Folder: Allows you to choose a directory of Alphas to be added to the “Folder” list.
  • Add Existing Folder: Allows you to choose a single Brush alpha from a folder, thus adding all the alphas in the folder to be included in the folder, now with the name of the chosen file, which is then listed in the “Folder” selection list.
  • Add Brushes From Package: Adds Alphas that have been packaged into a “Penpack” file format.
  • Folder: A selection list of all folders you have enabled 3DCoat to access. The icons from this chosen folder will then be visible in the “Brushes Panel”.
  • Tiny (or Normal, Large and Huge): Sets the Alpha icon set to the size specified.

Stroke Mode Panel

Brush Components - Stroke Modes

In the Stroke Mode Panel you will find various stylus pressure modes, lasso modes and curve modes. Each of these modes allows you to control your strokes either with pressure, using a curve as a path, lassos and more. This panel contains some of the most versatile aspects of a brush in 3DCoat. From left to right, these are:

  • Radius & Depth Pressure: Stylus pressure affects radius and depth.
  • Depth & Opacity Pressure: Stylus pressure only affects draw depth.
  • Radius, Depth & Opacity Pressure: Stylus pressure modifies radius, depth, and opacity.
  • Droplet Pressure: Increasing pressure decreases radius and increases depth and opacity.
  • Constant Pressure: Draw with constant depth and radius, regardless of Stylus pressure.
  • Dot Stroke: Apply the current Brush with discreet dots. Dot spacing depends on the speed of your stroke.
  • Vertex Lines: Creates perfectly straight lines. Click to place a vertex, repeat to place more than one. Click starting vertex to make a closed shape. Press ESC to start a new line.
  • Vertex Curves: Creates interpolated curves. Click to place a vertex, repeat to place more than one. Click starting vertex to make a closed shape. Press ESC to start a new line.
  • Curve Stroke: In this mode you may draw very accurate and controllable strokes defined by splines. Click to add points to spline. Each point has own radius. Press ESC to end spline chunk. Click again to start new chunk. Press RMB over points to change point sharpness or smoothing. Click LMB to assign new radius to the point. If you click on the first or last point of the chunk you may expand the chunk. You may split curves and drag points via LMB. Use DEL key to delete points. Pay attention to the small square over the spline, you will find different options there and define pressure flow. Press ENTER or double-click to draw stroke. Pay attention that brush radius is shown only for points attached to the surface.
  • Stamp Mode: LMB Click and drag to vary size. Center is origin of your click. Release to place.
  • Stamp Drag Mode: LMB Click and drag your brush, release to place. Dependent on brush size.
  • Square Lasso: Paint with a square. After activated press SPACE bar to enter square size manually.
  • Rectangle Lasso: Paint with a rectangle. This mode works with almost every tool. You can paint, freeze, fill, or make planes with the rectangle. Use modifier key to make it square (it is ‘Q’ by default).
  • Vertex Lasso: Paint by surrounding an irregular area. Click to add vertices to the curve. Double click, or press on the starting vertex to finalize contour. Press ESC to cancel the contour, BKSP to delete the last vertex. This mode works with almost every tool. You can paint, freeze, fill, or make planes with contour.
  • Stroke Lasso: Paint with drawn contour. Draw by holding the LMB, release to apply. This mode works with almost every tool. You can paint, freeze, fill, make plane with contour.
  • Circle Lasso: After activated press SPACE bar to enter square size manually.
  • Ellipse Lasso: Paint with an ellipse. Use modifier key to make it exactly round (it is ‘Q’ by default).
  • Closed Spline: Draw with closed spline. Press ESC to stop adding points. Hover over a vertex press RMB and drag to change vertex smoothness/sharpness. Press DEL key to delete point. Click to insert point in the middle. Double click or press ENTER to draw the area. Use control panel (half diamond) on the top right to edit spline.
  • 3D Closed Spline: Draw with closed spline over surface in 3D. Usual splines act through projection, this mode works not in projection but in 3D space, it allows to make selection right on the surface. It is mostly applicable in Sculpt Room related tools. Press ESC to stop adding points. Use RMB to change vertex smoothness/sharpness. Press DEL to delete point. Click to insert point in the middle. Double click or press ENTER to draw the area. Use control panel on the top right to edit spline.
  • Single Polygon: One click will paint a single polygon, while holding down the LMB will paint up to the borders of all “source” polygons.

Brush Options Panel

Brush Components - Brush Options Panel

The Brush Options panel contains most of the brush related functions. These are

  • Brush rotation: This sets the initial orientation of the alpha at the beginning of the stroke.
  • Zero Pressure Radius: When using a tablet stylus, this number indicates the default radius at the beginning of the brush stroke.
  • Depth Modulator: The default depth for each brush being used.
  • Rotation Amplitude: Sets the amplitude for additional brush rotation.
  • Radius Variation: Sets the percentage of random brush radius variation.
  • Depth Variation: Sets the percentage of random brush depth.
  • Opacity Jitter: Defines the randomness of the brush opacity setting.
  • Jitter: The overall randomness of brush behavior.
  • Hue Jitter: Defines the randomness of the brush hue when used for painting color.
  • Brightness Jitter: Varies the brightness, randomly, over the course of a stroke.
  • Saturation Jitter: Varies the saturation of the primary color, randomly, over the course of the stroke.
  • Vary Color Per Stroke: Use this option to produce painting effects, like fur or hair, when you need to either vary the Hue/Saturation/Brightness as you paint a single stroke, (variegated strand color), or when you want each stroke made to have a slightly different Hue/ Saturation/Brightness, as determined by the corresponding “Jitter” setting.
  • Random Flip (X, Y): This randomly flips the selected brush either across its x or y axis while painting.
  • Paint w/ Dabs: Creates paint or sculpting “dabs” which occur at some set spacing – as determined by the “Spacing” control.
  • Rotate Along Stroke: When using brush alpha shapes that you want to align like the bristles of a brush – so that they change relative direction as the brush changes direction, all along the stroke – use this option.
  • Skip Eraser: Disables the “Erase Layer” of the Brush.
  • Sharp Shape (Sharp Shape w/ All Alphas): This check box allows to draw alphas more sharply (it is closer to old-style 3DCoat painting). Spots will not blend between each other. It means better following alpha shape but also sharper stroke self-intersection. This option is not working for airbrush and native (not surface) voxel tools. Airbrush and voxel tools are always working in sharp mode
  • Fade On Edge: All strokes painted with this option checked will have a smoother edge transition.
  • Use Spacing: When used with the “Paint w/ Dabs” option, adjusting the “Spacing” percentage slider determines how close or far apart the paint dabs are applied.

Top Bar Options

Brush Components - Top Bar

Both Brush “Falloff” and “Smoothing”, as well as a spline-based, directional interpolation can be used by ticking the check box and and entering a numerical value.

Height/Color Limiter

Brush Components - Height,Color Limiter

Another very important feature on the Top Bar, is the Height/Color Limiter. This function allows you to, for example, paint more in a cavity, or more on peaks, or more on a specific color or even a mask. It’s a helpful way to paint in details such as grime around nuts, or rusty colors in rust spots.

You may also like...