"multilayer paint"
Shader	Reflectance "multilayer paint"( "lacquer specular factor" LtFloat 0.3 "lacquer transmission factor" LtFloat 0.9 "lacquer mirror factor" LtFloat 0.2 "lacquer roughness" LtFloat 0.1 "lacquer refraction" LtFloat 1.59144 "metallic layer factor" LtFloat 0.0 "metallic flakes" LtEnum LI_PO_PAINT_ALUMINIUM "metallic shader" LtShader NULL "metallic roughness" LtFloat 0.1 "metallic scale" LtFloat 1.0 "metallic amplitude" LtFloat 0.1 "metallic detail" LtInt32 3 "metallic sharpness" LtInt32 1 "base ambient factor" LtFloat 0.2 "base diffuse factor" LtFloat 0.7 )
Synopsis	Empirical simulation of multi-layer paint surfaces.
Location	lishpro
Description	A reflectance that simulates the effects of multi-layer paint used in the automobile industry. The reflectance effect is achieved by a combination of several difference reflectance model into a single shader. The shader is build using a combination of other reflectance shaders. This means that there will parameter duplications. This is necessary to allow for individual control of each layer's properties such as the reflection from the lacquer layer and the metallic layer. The lacquer layer is based on the `dielectric' reflectance shader. The main modification is the removal of the transmission ray tracing. Instead the transmitted colour is calculated by the reflectivity of the underlying layers. The metallic layer is based on the `conductor' shader rather than the `metal' shader since the former is more physically accurate. This layer is to simulate the metallic flakes present in real metallic paints. A rough displacement shader is used rather than micro-facets to simulate the distribution of the flakes surfaces in the paints. The incident ray is the transmitted ray from the lacquer layer rather than the original incident direction. Likewise, the reflect ray from the flakes will also be refracted by the lacquer layer. This layer is optional and its contribution is determined by the `metallic factor'. The pre-defined metals currently are LI_PO_PAINT_ALUMINIUM, LI_PO_PAINT_SILVER and LI_PO_PAINT_GOLD. The base layer is the actual colour of pigment in the paint surface. As a result, it is assumed to be a Lambertian surface and is based on the `matte' surface. Like the metallic layer, the incident ray is the transmitted ray from the lacquer layer and thus is subject to possible total internal reflection at certain viewing angles. This layer's contribution is combined with the metallic layer before being filtered by the lacquer layer for the overall colour. The exact meaning of each of the arguments is given below: "lacquer specular factor" Specular factor for the lacquer layer. "lacquer transmission factor" Transmission factor for the lacquer layer. The underlying colour is filtered by this value. "lacquer mirror factor" Mirror factor for the lacquer layer. "lacquer roughness" Roughness of the lacquer layer. "lacquer refraction" Refraction index of the lacquer layer. "metallic layer factor" Contribution of the metallic layer. The inverse determines the contribution from the base layer. "metallic flakes" Select the 'metal' of the flakes. "metallic shader" Reflectance shader to be used to represent the metallic layer. If set, this replaces the internal method. For example, "metal" or conductor. Note: if this parameter is used to specify an external metallic shader, the following five parameters which relate to the internal metallic shading method will no longer be meaningful. "metallic roughness" Sharpness of the flakes' reflection. This is similar to the 'conductor' shader 'roughness' parameter. "metallic scale" Taken from 'rough' to simulate micro facet surfaces. "metallic amplitude" Taken from 'rough' to simulate micro facet surfaces. "metallic detail" Taken from 'rough' to simulate micro facet surfaces. "metallic sharpness" Taken from 'rough' to simulate micro facet surfaces. "base ambient factor" Ambient factor for the base layer. "base diffuse factor" Diffuse factor for the base layer. Previous page alphabetically (mosaic) Next page alphabetically (nonebackground) Index
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