STEP by STEP Create LIGHT EFFECTS WITH SCATTERING MEDIUM
01 PREPARE the geometry
For this scene, create a sphere serving as an object to illuminate. Apply a Soft Shiny Grey material. Add another smaller sphere as the source of light and position it above the big sphere. Create a ground plane and apply a Plastic Expanded Polystyrene Displace material. Add a box and scale it up to cover the entire scene. Press O on the keyboard to bring up the Geometry view.
02 Scattering Medium
Apply your choice of spotlight material to the small sphere and adjust its Power. If you want to simulate the gobo effect, choose a spotlight with a light-controlling stencil. Apply the black environment HDRI to the background for better contrast. Double-click on the box to open the Material tab and in the Type menu select Scattering Medium. Up the Transparency Distance and lower Density.
03 Add fog
The next step is to fake a realisticlooking fog or smoke effect. Make sure you have the cube material selected and in the Material menu navigate to the Textures section.
Select the Density Texture slot and from the drop-down menu choose the Volume Map option. Choose a VDB map and then move the texture to the right position.
04 flakes And dust
To create flakes or dust, add a new geo to the scene, for example a cube. Scale it up to cover most of the lit-up part of the scene. Apply a material to it, in this instance Metal. Open the Material Graph and right-click to bring out the node ribbon. From the options select Geometry>flakes. Double-click on the Flakes node to see its edit menu. Adjust the Size and Density sliders to your liking.