Features

• Brush / spray viewpoint rendered by camera -> resembles individual particles
• Achieves realistic and fine painting across multiple meshes
• No PhysicsServer or CollisionShapes needed. (Relies fully on 3D rendering techniques)
• Works at runtime & in editor
• Up to 8 overlay texture atlases per scene
• Arbitrary amount of meshes per atlas
• Arbitrary brush shapes provided by an image
• Resolution and other performance settings

For bug reports, feature requests and questions please open an issue on GitHub

Usage

The addon adds two nodes: The OverlayAtlasManager for the management of materials and textures and the CameraBrush for painting onto the textures.

For an example configuration open the demo scene

Overlay Atlas Creation

• Add OverlayAtlasManager Node as sibling or parent to MeshInstance3D nodes.
  • Use hierarchy for compartmentalization of atlases.
  • All meshes need to have the UV2 unwrapped as described here.
• Set the wanted texture size.
• Set the shader file used for the overlay material. See Appearance of the Overlay.
• Press "Generate atlas and apply shader" to generate the atlas packing and apply the overlay shader material to all materials.
• Alternatively, call the apply() method in a script.
• Alternatively, select Apply on ready. Useful for MeshInstance3Ds inside PackedScenes.

Camera Brush

• Add a CameraBrush Node to the scene. Make it a child of the camera for example, to make it moved by the player.
• The Projection mode controls the type of the brush:
  • Perspective: Paint spreads, e.g. spray cans
  • Orthogonal: Brush size stays constant, e.g. pencils
• FOV/Size: The size of the brush
• Max Distance: The range of the brush. (Affects performance)
• Start Distance Fade: At which distance the brush should start to fade to full transparency.
• Bleed: How many texels should be drawn in the atlas around the texels rendered by the CameraBrush. Increase to reduce artifacts. (Affects performance)
• Brush Shape: Image of the brush shape. The R Channel dictates, how much paint is applied.
• Resolution: Resolution of the CameraBrush render target. Increase or decrease until holes in the painting disappear. (Affects performance)
• Color: Color of the brush. Opacity can be set.
• Draw Speed: The rate at which the paint is applied.
• Drawing: If enabled the brush renders and paint is applied. Can also be set from script.

Appearance of the overlay

• Duplicate the overlay_template.gdshader file.
• Insert your custom shader code at the placeholder.