The Spacing and Area tools are a quick and efficient way to scatter and manipulate large amounts of assets in your scenes along paths you create or within areas you define. You can distribute several types of assets randomly or systematically, in large or small areas, and create variety by defining the density of the populated paths and areas and fine-tuning how the assets are distributed.
You can use assets from the Twinmotion Library, including the User library, as well as assets you import into Twinmotion. Once the assets are added to the paths or areas you create, you can modify their properties such as their scale, rotation, and distance above the surface.
You can use the Spacing and Area tools in several situations, for example to:
Add trees and street lights along city streets.
Populate parking lots with various types of vehicles.
Add rows of hanging or recessed lights along ceilings.
Create forests with diverse trees and vegetation within defined areas.
The Spacing and Area tools work in similar ways, but they distribute assets differently.
With the Spacing tool, you can distribute assets along open or closed paths.
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With the Area tool, you can distribute assets within defined areas.
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Splines
The Spacing and Area tools are spline-based. Using the Pen tool, you draw splines in the Viewport that represent paths or areas.
Paths are splines that can be open-ended or connected at their ends.
A path created with the Spacing tool.
Areas are splines that connect at their ends to create an enclosed space.
An area created with the Area tool.
The splines are drawn in segments and separated by spline points you define. The shape and dimension of the splines can be modified and are controlled by the spline points.
A spline is comprised of the following elements:
1- Spline point: Defines where a segment of the spline starts and ends.
2- Plus sign: Click on the Plus sign to create a new spline point.
3- Arrow: Shows where the assets will be distributed along the path or in the area. You can customize the distribution method with the Scattering properties.
Working with Splines
| To... | Do... |
|---|---|
Edit the shape of a spline. | With the Translate tool click on a spline point and move it. |
Add a spline point. | Click on the Plus sign on the spline. |
Create an endpoint for a spline. |
|
Add a segment to an existing spline. | Select the spline and click the Pen tool. |
Delete a spline point. | Select the spline point and press Delete on the keyboard. |
Supported Asset Types
You can use the Spacing and Area tools with assets you import into Twinmotion and with the Library assets in the following categories:
Vegetation (excluding Landscapes and Detail grasses)
Objects (excluding Water, Sounds, Doors)
Lights
Megascans
Sketchfab
Posed humans in Characters
Limitations
Skeletal mesh animations are not supported.
Assets can only be placed on horizontal surfaces.
Using the Spacing and Area Tools
Open the Populate panel by clicking Populate in the Footer.
In the Populate panel, click the Place tab, then click the Spacing or Area tab.
Click the Pen tool icon.
If you are using the Spacing tool, draw a path in the Viewport.
If you are using the Area tool, draw an area in the Viewport.
Each spline you create with the Spacing or Area tool appears as a separate element in the Scene graph.
Paths and areas in the Scene graph.
Add the assets to the path or area by selecting them from the Library and dragging them to the dropbox.
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The assets you add to the dropbox are automatically placed on the path or in the area. By default, the assets are uniformly placed.
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Keeping the path or area selected use the settings in the Properties panel to modify the spline or the assets. For more information about the properties you can modify, see Scattering Properties and Object Settings.
Scattering Properties
When you select a path or an area, the scattering properties you can modify appear in the Properties panel. You can use these to modify how assets are spaced along a path or within an area using randomization seeds, object count and spacing, and more.
Scattering properties for the Spacing and Area tools.
Spacing Tool
The following table describes the scattering properties you can modify with the Spacing tool.
| Property | Description |
|---|---|
Random seed | Specifies the value that is used to randomize the distribution of the assets along the path. The same seed value always gives the same randomization results. You can enter the value manually, or click the icon to automatically generate random seed values.  Random seed icon. |
Path tension | Sets the tension of the segments between spline points. The higher the percentage, the straighter the segments are between the spline points. By default, the tension is set to 50\%. Options: 1\% to 100\% |
Random lateral offset | Sets the offset distance between the assets and the spline, according to Count or Distance.
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Random order | Randomizes the placement of objects along the spline when more than one object is in the dropbox. By default, objects are placed on the spline in sequence, in the same order they appear in the dropbox, and this sequence is repeated along the path. |
Area Tool
The following table describes the scattering properties you can modify with the Area tool.
| Property | Description |
|---|---|
Random seed | Specifies the value that is used to randomize the distribution of the assets along the path. The same seed value always gives the same randomization results. You can enter the value manually, or click the icon to automatically generate random seed values.  Random seed icon. |
Path tension | Sets the tension of the segments between spline points. The higher the percentage, the straighter the segments are between the spline points. By default, the tension is set to 50\%. Options: 1\% to 100\% |
Spacing | Sets the spacing between the assets within the area. Options: 1.00 m to 6.00 m |
Random spacing | Randomizes the position of the assets by a maximum distance of the Spacing value. Higher Random spacing values increase the randomness. Options: 0.00 to 1.00 |
Probability | Determines the density of assets which are spawned. A value of 0.00 removes all assets, and a value of 1.00 spawns all assets. Options: 0.00 to 1.00 |
Edge falloff | Reduces the density and scale of the assets along the edge of the area based on the Falloff distance value. |
Falloff distance | When the Edge falloff check box is selected, this value determines the distance from the edge of the area to apply edge falloff. Options: 0.00 m to 20.00 m |
Object Settings
When you select an asset in the Spacing or Area tool dropbox, the settings you can modify for the asset appear in the Properties panel.
Object settings for the Spacing and Area tool.
| Setting | Description |
|---|---|
Scale offset | Multiplies the scale of the asset scale with the Scale offset value. Options: 0.001 to 5.00 |
Random scale | Randomly scales the assets by a maximum scale of the object scale. Taking into account the Scale offset value. Options: 0.0 to 1.0 |
Rotation offset | Sets the rotation of each asset to a fixed angle in degrees. Options: 0.00 to 360.00 |
Random rotation | Adds a random rotation angle to the asset in either direction. The higher the value, the higher the angle. A value of 1.00 randomizes the angle in 180 degrees in either direction, and a value of 0.50 randomizes the angle in 90 degrees in either direction. Options: 0.00 to 1.00 |
Snap to surface | Snaps the assets to the first surface below the spline. You can specify whether or not assets snap to a surface using the Object Collision feature. If collision is disabled on a surface, the assets do not snap to the surface. |
Align | Re-orients the assets to align with the surface normal. |
Spacing and Area Tools Dropbox
Clicking the ellipsis (...) that appears when you hover over the assets in the dropbox opens a menu where you can access commands.
Dropbox asset menu.
| Command | Description |
|---|---|
Delete | Removes the asset from the dropbox and the path or area. |
Go to library | Opens the folder in the Library panel where you selected the asset. |
Split | Splits assets that are composed of multiple parts (meshes) into separate parts that appear in the dropbox. This can be useful if you want to use only one specific part of an asset in a path or area. |
Object Collision
When you select certain objects in the scene, a Collision section that contains an Exclude from Spacing and Area tools check box appears in the Properties panel.
By default, collision is enabled between the objects in the scene and the assets that are placed along paths and within areas. However, you can disable collision by selecting the Exclude from Spacing and Area tools checkbox. To do this, follow the steps below.
You can disable collision for the following types of objects: Imported objects, furniture, vehicles, characters (excluding Cutout characters), vegetation (excluding Grass and flowers and Detail grasses, Quixel Megascans, and Sketchfab.
Select the object.
In the Properties panel, select the Exclude from Spacing and Area tools checkbox.
Select the Spacing or Area tool path or area.
Click the Update button.
Clicking the Update button, changing the Random seed value, moving the Spacing or Area tool path or area, or closing then reopening a Twinmotion project recalculates the collision between the scattered objects and the other objects in the scene.