Advanced Specularity Control

LightWave's built in shading allows you to select the intensity of the surface specularity, one of four fixed glossiness settings, and the option of using the surface color as the highlight shade. It uses a classic but simple algorithm to determine the strength of the specularity. Unfortunately, this is simply not enough control!

New Specularity Model

Gaffer applies its specular highlights using a more advanced, physically based formula which has been developed specifically for realistic behavior. Known as the "HTSG" model, it was introduced in 1991 and is the most physically accurate model in computer graphics (currently, anyway).

Numeric Glossiness

Specularity Colors

LightWave allows an option for using the surface color or light color for highlights. In Gaffer, you can blend between these colors in any proportion. You can also select an arbitrary color response for a highlight, which can also be blended with the surface color. Often metals will have specularities which are tinted towards a shade that's different than both the main surface color and light color.

Layered Specularities

You can layer specularities, summing their effects. A car's surface has a very broad, colored highlight from the surface paint, but superimposed on top of this there is a tight, white highlight from the clear surface coating and wax. Gaffer allows you to easily superimpose highlights like this, which is extremely important for metals (which often have multiple color responses), for paints (where surface reflection is usually tighter and less colored than the scattering from the suspended paint particles), and for wet surfaces, where the surface layer of water adds its own specularity to the normal surface behavior.

The Fresnel Effect

Surface reflection changes depending on viewing angle. Known as the Fresnel effect, surfaces become much more reflective at glancing angles. The edge of objects will usually have highlights that are much stronger at glancing angles than they are when viewed flat-on. Gaffer gives you control over this effect, including setting the intensities, position, and transition width of this falloff.

Note: The images above to the left also show before and after examples of Gaffer's Area Light Shadows, Selective Lighting and Lighting Intensities. See related sections for more details.