Brush painting
This page explains how to use the Brush paint mode
Summary
Published: May 24 2026 by Akiway Last documented edit: May 24 2026 by Akiway
What is it for?
Brush painting allows you to add elements randomly to an area using a brush tool. The randomization of its content can be configured in two ways :
The probabilities : It defines how many of each element could appear at each stroke, it uses the existing features of Randomized groups.
The variations : It is global to the brush tool and defines if randomization should also apply to the properties of the elements (size, rotation).
Requirement
World Builder - Akiway's fork (a.1.3.0 or newer)
Akiway's fork of World Builder is a more advanced version that put the focus on Quality of Life.
The version a.1.3.0 brings the new Brush painting feature.
How to use
Prepare the brush
You first need to determine what you want to paint. Start by creating a randomized group .
Then fill this group with elements you want to paint.
(Optional) In this group, you can define the probabilities of each item appearing on each stroke. For more details on how to configure a randomized group , see the dedicated page : Creating a RNG
You can save it as a prefab in the context menu (RMB) of the randomized group . Your prefabs will then be located in Spawn New tab > Favorite. I invite you to create a "Brushes" category to group all your best brushes.
Setting the brush
The brush is only available in 3D Editor mode, so starts by enabling it in the Spawned tab then enable the brush paint mode .
Settings are :
Size : radius of the brush circle.
Intensity : quantity of strokes per second.
Rotation variations : enabled axes will randomly change value for each element.
Scale variations : each element will spawn with a scale value in-between the variation set.
Dot painting : performance option, described below (Dot painting option).
The brush status has a tooltip that gives you info on it. Configuration issues are listed inside.
Select the source and the target
At this point you should have a randomized group and the brush paint mode enabled.
You now need 2 things : a source (our brush with elements to spawn) and a target (the group that will contain your painted content, i.e. the final result).
To set the source, simply click on the randomized group , its hierarchy row should turn green.
To set the target, create a normal group and set it as the "Spawn New" group . To do it you can select your group and press CTRL+N, or use the group's context menu and select the corresponding option.
Paint
If you've configured your brush correctly, its status should reflect it.
When hovering the world with your cursor, a green circle should appear with a size indicator.
Left-click in the world to paint. You should see elements appear in your target group as well as in the world.
The more you paint, the worse your performance will be.
Loading and spawning a large number of elements during runtime consumes a lot of resources. The more elements your brush (source group) contains, the more it will generate with each brush stroke, and so the quicker performances will decrease.
If you need to paint a lot of things while keeping great performances, check out this section : Dot painting option.
Finish
When satisfied, simply disable the brush paint mode .
If you need to add something more after, enable it again and go back to step 3 : Select the source and the target.
Dot painting option
If you encounter bad performances while painting, consider the dot painting option.
Using this, painted items will be loaded but not spawned. Instead, a dot will appear on the screen at the exact same position to give you an instant feedback.
Having trouble seeing the dots on the ground? You can change their color using the color picker (colored square) located to the right of the dot painting toggle.
Dots will disappear when you disable the brush paint mode . To view the final result, simply use the " Show all children" option in the target group's context menu.
Erasing
To erase, simply press SHIFT while painting, this will remove all elements located inside the brush circle.
In-world brush circle should turn red when you are in erase mod.
Don't worry about erasing unwanted content. The eraser only remove elements that are inside the target group , and it only removes the elements that are part of the brush (source group).
So any content placed outside of the brush won't get deleted. And if anything wrong happens anyway, you can always use the undo / redo actions, they work with the brush paint mode .
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