environmentalHdrSpecularFilter

SpecularFilter applies a filter based on the BRDF used for lighting

Specular highlights are the shiny bits of surfaces that reflect a light source directly. Highlights on an object change relative to the position of a viewer in a scene.

true = Reduce the amount of reflectivity a surface has. It is a key component in determining the brightness of specular highlights, along with shininess to determine the size of the highlights.