Reflectance is a surface property. It is the amount of incident light being reflected from the material or decal surface. Reflectance is a directional property and all the surfaces have a combination of diffuse and specular properties.
The following are the Reflectance options available in the drop down list:
| Constant | The surface will be of a constant color. |
| Matte | The surface will appear as a dull matte. |
| Metal | The surface will have a specular metallic finish. |
| Phong | The surface will have a shiny or highly polished material finish such as ceramic or glass. |
| Plastic | The surface will have a glossy plastic-like finish. |
| Chrome 2D | The surface will have a chrome-like effect. This effect is generated by a reflection pattern from a two dimensional array of colors. |
| Conductor | A surface where the reflectance supports secondary mirrored views through ray tracing. |
| Dielectric | A surface where the reflectance supports an accurate simulation of dielectric (glass-like) materials that have both reflective and transmissive properties. |
| Environment | The surface that will have environment mapping. |
| Glass | The surface will appear glass-like reflectance. |
| Mirror | A surface finish that supports secondary mirrored views. |
| Wrapped mirror map | A surface finish that supports secondary mirrored views through ray tracing. |
| Radiosity stepped false | Produces false color rendering of luminance and luminosity values, when rendering scenes lit using global illumination (e.g. radiosity) or high dynamic range image (HDRI) based lighting. |
| Translucency | The surface will be translucent and have backlit effect. |
| Plastic translucency | The surface will have a specular effect which is similar to the Phong surface with translucency. |
| Wrapped circular anisotropic | The surface will appear having many small areas of concentric rings of scratches or ridges repeated over the surface. |
| Wrapped woven anisotropic | The surface will appear as of woven materials such as satin cloth. |
| Multilayer paint | Simulates paint surfaces with base color, optional metallic flakes, and a separate lacquer layer. Such paint effects are often used in the automobile industry. |
| Shadow catcher | Allows the shadows to fall upon the surface on which the shadow catcher is applied. The objects hidden by this surface will be visible. |
| Wrapped anisotropic | The surface will have a parallel scratches or ridges, such as brushed metal. |
The way light is reflected by a surface depends on several factors, such as the nature of the light source, direction and properties of the surface.
Reflected light is of two types:
| Specular Reflection | Light reflected in a certain direction, depending on the angle of incidence, wave length and surface properties. This type of reflection is similar to shiny surfaces. |
| Diffuse Reflection | Light scattered equally in all directions, so that the surface appears to have the same brightness from all viewing angles. This type of reflection is similar to matte surfaces |
The following are the main parameters controlling the reflectance.
| Ambient Factor | This is the ambient light. The ambient light comes from all the directions and not from any specific source. |
| Diffuse Factor | It is diffuse reflection, which is the same in all directions and does not depend on the observer's position. |
| Specular Factor | It is specular reflection, which can be observed on any shiny surface where it generates highlight zones, which move together with the observer. |
These other main options which are available for selection of some particular reflectance options.
| Refraction | It is the index of refraction for all wavelengths of light. When a light ray passes from a medium to another, it is inclined by a certain angle that is called the refraction angle. Each material has its own index of refraction that determines the refraction angle (as stated by Snell's law). |
| Transmission factor | It is the light passing through a surface in the transmission direction. |
| Translucency Factor | When light passes through a surface with internal irregularities, an object seen through translucent material can be more or less blurred depending on the translucency parameter value. |
| Mirror factor | It is the light reflected in the mirror direction. |
| Roughness | It controls the sharpness of the specular reflection highlights. The reflection is made sharper with small values for the roughness, such as 0.1 or less. Larger values such as 10.0, decrease the specular fall-off |