Flood fill

Jump to Mobile

To fill an area with paint, tap the paint bucket  icon, then tap a region to fill. To successfully fill an area, the area must be closed, which means it has no gaps of transparent pixels.

In this example, the first image has a closed area. The second shows a successful fill. The third is the finished product. The fill layer’s opacity was reduced to mute the fill and allow an underlying layer to peek through.

If the fill area is not closed, the fill will invade areas you didn’t intend to color. In the example below, the area in the first image is NOT closed. When a fill is applied in the center it also affects the background due to the shape not being closed. 

When you tap  the Flood Fill toolbar appears containing fills an assortment of tools. Use the tools to change the type of the fill, set fill tolerance, change whether the area to fill is sampled from the active layer or all layers, or adjust settings for gradient fills.

Types of Fill

 Solid Fill

Fills an area with paint.

 Gradient Linear Fill

The gradient color ramp applies linearly from your first tap (origin) to the end of the drag (destination). This establishes the direction and size of the ramp. Fill manipulators can be added, moved, and removed.

 Gradient Radial Fill

The gradient color rap radiates from your first tap (origin) to the end of the drag (destination). Fill manipulators can be added, moved, and removed.

Fill Tolerance

Did the fill cover more area than you wanted? Did it not cover enough? Change the tolerance of your fill to determine the range of the area/colors affected.

The minimum tolerance, 1, selects and fills only pixels of that color value. The maximum tolerance, 255, selects and fills all pixels within the region.

At higher levels of tolerance, the region will need to be closed with a more solid line - for example, brushes with soft edges, texture, and/or opacity will not create a closed area for a fill with tolerance set at 255.

Sampling layers

Sampling refers to which pixels the fill tool will reference when determining the boundaries of the fill. You can choose to sample from the current layer or all layers for your fill:

•   Sample One Layer references only the pixels on the active layer for the fill's boundaries.
•   Sample All Layers references pixels on all visible layers for the fill's boundaries. The contents of hidden layers will not be referenced.

In the first image below, we used Sample One Layer, so the doll's head was the only area used to define the fill.

In this section image, we used Sample All Layers and tapped in the area within the head, where the arm is visible. So, though the lines of the arm are on a different layer, they help define the filled area.

Using Flood Fill in Sketchbook Pro for desktop

1. Fill options
2. Tolerance
3. Sample All Layers
4. Reverse
5. Cancel and OK

Flood filling an area

• In the toolbar, tap .
• Choose your fill type - solid, linear gradient, or radial gradient.
• Tap  to fill based on sampling the current layer, or  to sample all visible layers.
• Tap the area you want to fill. The fill will automatically apply.
  • If it is a gradient fill, you have an opportunity to adjust the handles before tapping  to accept or  to cancel.

Changing fill tolerances

In the Fill toolbar, tap-drag the slider to change the fill tolerance.

• Increase the tolerance to increase the range of colored pixels affected by the fill.
• Decrease the fill to reduce the range of affected pixels.

Creating a gradient area

You can start a fill and then set the gradient colors using the handles, or select a pre-defined gradient fill from the Color Puck's Gradient Fill Palette.

1. Select the Flood Fill tool ,
2. Select either linear or radial gradient fill from the Flood Fill toolbar.
3. Click-drag to place the gradient manipulators for the fill where you want them. You can also single-click the area to be filled, the gradient manipulators will be placed automatically.
4. To refine your gradient:
   1. Change the color of any manipulator by tapping it and then selecting another color.
   2. To select a different gradient fill from the Gradient Palette, tap any manipulator and then select another gradient from the palette.
   3. Tap-drag any manipulator to reposition it.
   4. To add a manipulator, tap along the axis between manipulators.
   5. To delete a manipulator, tap the manipulator to activate it, then tap the  above it to remove it.

Inverting the direction of a gradient fill

While your gradient fill is still active - before tapping  to accept - click  to invert the order of the fill manipulators.

Using Flood Fill in Sketchbook for mobile devices

Filling an area

1. If on a tablet, tap  Fill.
   1. If on a handheld device, tap , then  Fill.
2. Select one of the fills. The default is   Solid Fill, which will apply immediately when you tap on the canvas
3. If using a gradient fill, you can further refine your gradient before it applies to the canvas
   1. Tap an area to start the fill
   2. To add a manipulator, tap anywhere along the fill line.
   3. To move a manipulator, tap-drag it to the new position.
   4. To remove a manipulator, tap-drag it away from the fill line. It will disappear.
   5. Tap to  accept the fill or  to cancel.

Changing flood fill tolerance

In the Fill sub-toolbar, tap-drag the Tolerance slider to change the value. If you're using a handheld/phone device, first tap  to expose the tolerance slider.

Increase the tolerance to increase the range of colored pixels affected by the fill. Decrease tolerance to reduce the range of pixels affected.

Sampling one or all layers

The Sample Layers icon is at the right end of the tolerance slider. If you're using a handheld/phone device, first tap  to expose the options.

Select one of the following:

• Tap  to fill based on sampling the current layer.
• Tap  to sample all visible layers.