Create a Sphere Object

In the Viewer pane press tab > Geometry and RMB-click to accept. Rename this object skydome. Press i to enter the skydome object. Delete the default file.

In the Viewer pane press tab > Sphere, change its Primitive Type to Polygon. Increase the Radius to 120, 120, 120, and the Frequency to 5.

Clip the Sphere into a Dome

In the Viewer pane press tab > Clip. Change the Origin-Y parameter to -20 to ensure that the edge of the dome will note be seen when viewing through the camera. Press the See One/See All objects toggle to see how the dome fits into your scene. Press w to see wireframe view if nessesary.

Create a Star Field Shader

In the Network pane press tab > SHOP Network, and press i to enter it. Press tab > VEX Polka Dots and rename the shader to stars. Press t in the Viewer pane until you get the grid shader icon. Change the following in the Parameter pane:

Dot Size to 0.02;

Softness to 0;

Dot Color to 1 1 1;

Base Color to 0 0 0;

Specular to 0 0 0;

Roughness to 0.001.

Assign the Shader

Press u twice to return to the object level. Under the Shading tab of sky, click on the [+] next to the SHOP Surface field. Navigate inside the shopnet within the sky object, when the stars shader is selected press Accept.

Test render to see how the skydome looks.