Creating Fluorescent Light by Light with Shape

You can activate Light with Shape attribute on the point and spot light for volumetric effects which can react with reflective surfaces. The following article will talk about creating fluorescent light reflection on a window glass material.

* Only reflective PBR materials support light reflections.

1. Create a project with reflective surfaces.
   
2. Create a spotlight by executing Create > Light > Spotlight.
   
3. Adjust the location and orientation of the spotlight to have it casting light onto the character. In this case, the reflection shows on the window glass.
   
4. Make sure the spotlight is selected and go to the Light section in the Modify panel. Change the Shape drop-down list to Tube.
   
   A new shape will be added to the Spotlight Gizmo and is reflected upon the glass.
   
5. Drag the Radius, Soft Radius and Length sliders to determine the desired shape of the fluorescent light.
   
   *Soft Radius determines the blurriness of the reflection.
   You will see the final reflection on the glass.