mi_metallic_paint

 
 
 

Category: mental ray > Materials

Shader Family: Surface Material

Output: Color

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:

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].

Lights

Creates a light list to specifiy which lights should produce the effect. For more information, see Using Light Lists [Direct Illumination].

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