SkyMeshDesc

The SkyMeshDesc class is a mesh descriptor that draws the sky, sun, and moon using atmospheric scattering. It provides realistic sky rendering using physics-based atmospheric scattering simulation.

The sun and moon positions are automatically calculated based on view.atmosphere.date and updated every frame.

In addition to the properties below, the common properties from the base class (position, rotation, scale, matrix, matrixWorld, visible) are available. See MeshDesc for details.

Properties

visible

Type: boolean

Description: Toggles the visibility of the sky mesh.

Example:

{ visible: true }

sun

Type: boolean

Description: Specifies whether to display the sun.

Default: true

Example:

{
  sky: {
    sun: true,
  }
}

moon

Type: boolean

Description: Specifies whether to display the moon.

Default: true

Example:

{
  sky: {
    moon: true,
  }
}

moonScale

Type: number

Description: Specifies the scale of the moon.

Default: 1

Example:

{
  sky: {
    moonScale: 1.5,
  }
}

moonIntensity

Type: number

Description: Specifies the brightness of the moon.

Default: 1

Example:

{
  sky: {
    moonIntensity: 0.8,
  }
}

sunAngularRadius

Type: number

Description: Specifies the angular radius of the sun in radians.

Default: 0.004675

Example:

{
  sky: {
    sunAngularRadius: 0.005,
  }
}

envMap

Type: boolean

Description: Specifies whether to render as an environment map.

Default: false

Example:

{
  sky: {
    envMap: true,
  }
}

Usage Examples

import ThreeView from "@navaramap/three";
import { SkyMeshDesc } from "@navaramap/three_default_descs";

const view = new ThreeView();
view.registerMesh("sky", SkyMeshDesc);
await view.init();

// Add a SkyMeshDesc
const skyDesc = view.addMesh<SkyMeshDesc>({
  sky: {
    visible: true,
    sun: true,
    moon: true,
    moonScale: 1.2,
    moonIntensity: 0.9,
    sunAngularRadius: 0.004675,
  },
});

Technical Details

SkyMeshDesc is implemented using the @takram/three-atmosphere library and provides the following features:

Physics-based atmospheric scattering simulation
Dynamic lighting based on sun and moon positions
Sky color changes according to time of day
Atmospheric shadow length calculation

The sky mesh is automatically updated based on camera orientation and always covers the entire viewport.