Category: mental ray > Materials
Shader Family: Surface Material
This shader is used to facilitate the rendering of metallic paint. You can use it to define the pigmentation layer and the metallic flakes, but not the clearcoat reflections.
To accomplish a full car paint effect, the metallic paint shader can be combined with mib_glossy_reflection and mi_bump_flakes shaders. To get all these connections automatically, use the mi_car_paint_phen shader, which also supports a dirt layer.
The metallic paint shader supports:
Diffuse reflection in the pigmentation layer producing color shifts at edges due to viewing angle and incident light angle.
Specular highlights from light sources in the metallic flakes suspended in the pigmentation layer. Including optional raytraced reflections in the metallic flakes.
Specular highlight from light sources in the clearcoat layer. Including an optional glazing effect.
| Name |
The name of the shader node displayed in the render tree. Enter any name you like, or leave the default. |
| ambient |
The ambient light color component. This parameter is treated differently to the ambient/ambience parameter pair of many other base shaders in that it is influenced by the other diffuse color parameters on this property page. It represents incoming light, rather than the object's ambient color. |
| base_color |
The base diffuse color of the material. |
| edge_color |
Represents the color shift between the base color and the edge color. The color seen at the edges usually appears much darker. For really deep metallic paints as seen on sports cars, the edge color tends to be almost black. |
| edge_color_bias |
Defines the falloff rate of the color towards the edge. The useful range is 0.0 to 10.0, where the value 0.0 turns the effect off. Higher values make the edge region narrower and lower values make it wider. |
| lit_color |
Defines the color seen in the illuminated area of the object's surface. |
| lit_color_bias |
Defines the falloff rate of the color towards the light. The useful range is 0.0 to 10.0, where the value 0.0 turns the effect off. Higher values make the colored region facing the light smaller/narrower, while lower values makes it larger/wider. |
| diffuse_weight |
Modifies the overall level of the diffuse color parameters. |
| diffuse_bias |
Defines the falloff of the diffuse shading. The useful range is 0.5 to 2.0, where 1.0 represents standard Lambertian shading. Higher values push the diffuse peak towards the light source, and lower values flatten the diffuse peak. |
| irradiance_weight |
Sets the influence of indirect light (photons and final gathering) on the surface. It is internally divided by PI, i.e. a value of 1.0 means the standard 1.0/PI weight. |
| spec |
The color of the primary specular highlight. |
| spec_weight |
Specifies the blend weight for the primary specular color. |
| spec_exp |
Defines the rate at which primary specularity decays outward. |
| spec_sec |
The color of the secondary specular highlight. |
| spec_sec_weight |
Specifies the blend weight for the secondary specular color. |
| spec_sec_exp |
Defines the rate at which secondary specularity decays outward. |
| spec_glazing |
Enables a glazed surface effect by setting a threshold on the primary specular highlight. This option makes the surface appear more polished and shiny. To create the effect of a new sportscar with a highly waxed finish, turn Glazing on. For the look of an old, beat-up car, turn Glazing off. |
| flake_color |
The color of the reflective flakes, which is generally white. |
| flake_weight |
A multiplier for the above color. |
| flake_reflect |
Defines the amount of ray traced reflection in the flakes, which allows glittery reflections of an HDRI environment, for example. The value of 0.0 turns the effect off. The effect should generally be very subtle and a value of 0.1 is often enough. The final intensity of the reflections also depends on the reflectivity color and the color weight. |
| flake_exp |
Sets the specular exponent for the flakes. |
| flake_decay |
Since flakes are inherently small, they can easily introduce rendering artifacts if their visual density becomes significantly smaller than a pixel. The flakes furthest from the camera may cause flicker in animation, or trigger unnecessary oversampling and long render times. To avoid this potential problem, set a distance at which the influence of reflective flakes fades out. Positive values reduce the Color Weight so that it reaches 0.0 at Decay Distance. A value of 0.0 disables any decay. |
| flake_bump |
Pick the bump shader to be used. The mi_bump_flakes shader is designed for this purpose, but any shader that modifies the normal vector (such as mib_passthrough_bump_map) can be used. The shader that drives the flake_bump parameter can also return a color, which will be the color (intensity) of the flake, or it can leave the color unmodified. |
| global_weight |
Modifies the influence of indirect light (photons and final gathering) on the object's surface. It is internally divided by PI. For example, a value of 1.0 means the standard 1.0/PI weight. |
| mode |
The mode selector for the light list. For more information, see Setting the Light List Mode [Direct Illumination]. |
Creates a light list to specifiy which lights should produce the effect. For more information, see Using Light Lists [Direct Illumination].
