Skip to main content
Before starting this tutorial, read:
The Grass Brush lets you paint Unity Terrain detail layers — grass, flowers, and mesh details — directly in the scene view. It gives you manual control over exactly where detail appears, while using the same density and filter systems as the Grass Stamper.

​
Before you begin

You need:
  • A Unity Terrain in your scene with at least one detail prototype configured in the Terrain Inspector.

​
Step 1 — Open the MegaWorld Window and select Grass Brush

Press Alt + Z to open the MegaWorld Window. In the Tools Panel, click the + button and choose Grass Brush, or click an existing Grass Brush instance.

​
Step 2 — Add a Group and prototypes

In the Selection Panel, click Add Type. Inside the Group, click Add Resource and choose Unity/Terrain Detail. Assign a detail prototype that matches one already registered in the Unity Terrain Inspector.

​
Step 3 — Configure Spawn Detail Settings

In the prototype settings, expand Spawn Detail Settings:
  • Density — maximum detail count per terrain cell.
  • Use Random Opacity — adds variation so painted cells get different counts, breaking up a uniform look.
  • Failure Rate — randomly skips some cells for a more organic, sparse result.

​
Step 4 — Add Mask Filters (optional)

Add Mask Filters to restrict painting by height, slope, or terrain texture. Filters are evaluated per stroke, so moving the brush to a slope that fails the filter will produce no detail there.

​
Step 5 — Paint in the scene view

Move your cursor into the Scene View. A brush preview shows the area that will be affected.
  • Click to paint once.
  • Click and drag to paint continuously.

​
What’s next

  • Use Grass Stamper to fill large areas automatically with the same Group settings.
  • Use Object Brush to paint trees or rocks in the same session.
  • Read the full Grass Brush reference documentation.