Cubemap tiles

Reduce the initial loading time and used bandwidth by slicing big cubemap panoramas into many small tiles.

This adapter is available in the @photo-sphere-viewer/cubemap-tiles-adapter (opens new window) package.

const viewer = new PhotoSphereViewer.Viewer({
    adapter: PhotoSphereViewer.CubemapTilesAdapter,
    panorama: {
        faceSize: 6000,
        nbTiles: 8,
        baseUrl: {
            left: 'left_low.jpg',
            front: 'front_low.jpg',
            right: 'right_low.jpg',
            back: 'back_low.jpg',
            top: 'top_low.jpg',
            bottom: 'bottom_low.jpg',
        },
        tileUrl: (face, col, row) => {
            return `${face}_${col}_${row}.jpg`;
        },
    },
});

Example

title: PSV Cubemap Tiles Demo
packages:
    - name: cubemap-adapter
    - name: cubemap-tiles-adapter
      imports: CubemapTilesAdapter

const baseUrl = 'https://photo-sphere-viewer-data.netlify.app/assets/';

const viewer = new Viewer({
    container: 'viewer',
    adapter: CubemapTilesAdapter,
    panorama: {
        faceSize: 1500,
        nbTiles: 4,
        baseUrl: {
            left: baseUrl + 'cubemap/px.jpg',
            front: baseUrl + 'cubemap/nz.jpg',
            right: baseUrl + 'cubemap/nx.jpg',
            back: baseUrl + 'cubemap/pz.jpg',
            top: baseUrl + 'cubemap/py.jpg',
            bottom: baseUrl + 'cubemap/ny.jpg',
        },
        tileUrl: (face, col, row) => {
            const num = row * 4 + col;
            return `${baseUrl}cubemap-tiles/${face}_${('00' + num).slice(-2)}.jpg`;
        },
    },
    caption: 'Parc national du Mercantour <b>&copy; Damien Sorel</b>',
    loadingImg: baseUrl + 'loader.gif',
    touchmoveTwoFingers: true,
    mousewheelCtrlKey: true,
});

Positions definitions

With this adapter, pixel positions require an additional textureFace attribute (example: { textureFace: 'front', textureX: 200, textureY: 800 }). The position refers to the full size of the face (first level when using multi-levels tiles).

Configuration

baseBlur

• type: boolean
• default: true

Applies a blur filter to the base image (option baseUrl).

showErrorTile

• type: boolean
• default: true

Shows a warning sign on tiles that cannot be loaded.

antialias

• type: boolean
• default: true

Applies antialiasing to high resolutions tiles.

Panorama options

When using this adapter, the panorama option and the setPanorama() method accept an object to configure the tiles.

You may choose to provide a single tiles configuration or multiple configurations which will be applied at different zoom levels, this allows to serve files adapted to the current zoom level and achieve very high resolutions without consuming too much bandwidth.

faceSize (required)

• type: number

Size in pixel of a face of the cube.

nbTiles (required)

• type: number

Number of columns and rows on a face. Each tile must be square. Must be power of two (2, 4, 8, 16) and the maximum value is 16.

tileUrl (required)

• type: function: (face, col, row) => string

Function used to build the URL of a tile. face will be one of 'left'|'front'|'right'|'back'|'top'|'bottom'. If the function returns null the corresponding tile will not be loaded.

flipTopBottom

See the cubemap adapter configuration.

baseUrl (recommended)

• type: any

URL of a low resolution complete panorama image to display while the tiles are loading. It accepts the same format as the standard cubemap adapter.

levels (required)

• type: array

Array of available tiles configurations. Each element is an object with faceSize and nbTiles (see "Single level") as well as zoomRange, an array containing the minimum and the maximum zoom level. The levels must be ordered and cover the whole 0-100 zoom range.

levels: [
    {
        faceSize: 3000,
        nbTiles: 4,
        zoomRange: [0, 30],
    },
    {
        faceSize: 6000,
        nbTiles: 8,
        zoomRange: [30, 70],
    },
    {
        faceSize: 12000,
        nbTiles: 16,
        zoomRange: [70, 100],
    },
]

tileUrl (required)

• type: function: (face, col, row, level) => string

Function used to build the URL of a tile. face will be one of 'left'|'front'|'right'|'back'|'top'|'bottom'. If the function returns null the corresponding tile will not be loaded.

flipTopBottom

See the cubemap adapter configuration.

baseUrl (recommended)

• type: any

URL of a low resolution complete panorama image to display while the tiles are loading. It accepts the same format as the standard cubemap adapter.

Preparing the panorama

The tiles can be easily generated using ImageMagick (opens new window) tool.

Let's say you have a cubemap where each face is 6.000x6.000 pixels and you want to split them into 8x8 tiles, use the following command for each face:

magick.exe front.jpg \
  -crop 750x750 -quality 95 \
  -set filename:tile "%[fx:page.x/750]_%[fx:page.y/750]" \
  -set filename:orig %t \
  %[filename:orig]_%[filename:tile].jpg

You can also use this online tool (opens new window).

Performances

It is recommanded to not exceed tiles with a size of 1024x1024 pixels, thus limiting the maximum panorama size to 16.384x16.384 pixels by face (1.6 Gigapixels in total).