@Dmitriy_the_Wombat

Since Sweet Home 3D 7.0, light panels are available in the LightShapes library by Emmanuel Puybaret (Invisible light panel) and the OtherLightTypes-1.5 library by myself (Unviewable panel - permanent).
These can be used with Sweet Home 3D's default photo panel and photo plug-in.
Consider uninstalling older versions of libraries if they are not replaced automatically.