Material Shaders - Car Paint

General綜述

The car paint material shader simulates the physical properties of most types of car paint. For computer graphics, car paint is generally modeled as three separate layers:

Car-Paint材質模擬了大多數車漆的光影物體性質。在計算機圖形學中，Car-Paint 一般分三層數學模擬：

1. Base pigment layer, with a diffuse color that can change depending on the viewing angle.

基礎顏色層，它漫反射顏色會隨視角不同而改變。

2. Metallic, reflective flakes that are embedded within the pigment layer.

嵌入在基礎顏色層中的金屬反光雜質。

3. A 『binder』, which is a shiny/waxed coating exhibiting very glossy reflection. Binder（黏合劑）它是外於最外層的光亮/蠟塗層，它的Gloassy Refection(光澤反射值)非常高。

Shader Options選項

Base Layer Diffuse底層漫反射

Pigment Color漆底色

This is the overall color of the paint pigment.

該顏色為整體塗料顏色。

Weight權重

This is a multiplier that scales the amount of diffuse lighting that can be

received. For correct energy conservation, this should be less than 1.

該選項為倍增器，用於縮放慢反射強度。為了保持能量守恆，這個屬性不應大於1.

Edge Falloff邊緣衰減

Edge Falloff Color顏色

This is the color that is seen at glancing angles, due to the Fresnel effect. Typically, very metallic paints have an edge color of black.

由於菲尼爾效果，這個屬性定義在側方向看到的顏色。通常來說，如果漆的金屬性很強，邊緣顏色應該是黑色。

Edge Falloff Curve Factor過渡參數

This controls the curve fall-off for the edge tint. The smaller the value, the『tighter』 the transition from the pigment color to the edge color, with a value of 0.0 meaning no edge color.

用於控制材質本身的顏色邊緣過渡曲線的變化程度。數值越小，邊緣顏色的過渡越劇烈，值為0時，邊緣顏色無效。

Base Layer Specular 底層高光

General綜述

Color顏色

This is the color of the specular reflection for the pigment layer. For a more realistic result, this color should be close to the pigment color.

該顏色用於設定藍色的鏡面反射。為了真實，該顏色應該接近底色。

Weight權重

This is a multiplier that scales the amount of specular reflection that can be received. For correct energy conservation, this should be less than 1.

該選項為倍增器，有於縮放鏡面反射強度。為了保持能量守恆，其設置不應大於1。

BRDF

New to 2.0 Feature

This allows you to choose the technique for simulating physically correct rough reflections. Beckmann is generally considered the standard for a good range of materials, but GGX has a wide specular tail, which is good for chrome materials.

Ashikhmin-Shirley (legacy)

Beckmann (Cook-Torrance)

GGX

Ashikhmin-Shirley

The legacy BRDF option uses a non-linear looking glossiness fall-off and exists

to maintain compatibility with 1.0 materials.

Glossiness光澤度

High glossiness means sharp reflections. Lower numbers will make the reflections blurrier. Paint pigment typically has a low glossiness.

Glossiness高說明反射清晰。參數設置越低，反射越模糊。漆通常光澤度較低。

Samples採樣

This controls the number of ray traced samples required for the glossiness. A value of 0.0 means 1 sample, with perfect specular reflection.The 『rougher』 the gloss, the more samples you will need to get rid of noise. Also be aware that the more samples you use, the longer it will take to render.

該選項控制光澤度所需的光線追蹤採樣數量。值為0時，說明每像素只1採樣一次，表明是清晰的鏡面反射。光澤度越越「粗糙」，就要用更多的採樣來降噪，另外請注意，使用採樣越多，渲染所耗時間越長。

Highlights Only僅採樣光源高光

This optimization option will disable indirect reflection ray tracing of the environment and just capture specular reflections from lights.

該優化選項將禁用材質對環境中的間接反射採樣，並只捕捉光源的鏡面反射。

Fresnel Control菲尼爾控制

Facing Reflectivity正向反射

This controls the strength of reflections when viewed head on, 0 degree angle from

the surface. The values range between 0.0 and 1.0. Typically, metals will have a high setting, with a perfect mirror being 1.0. Most materials with reflective coats, however, should have relatively low values, which is why the default is 0.1.

在視角與表面法線成0度，即從正面看時的反射強度。值的範圍在0.0和1.0之間。通常情況下，金屬參數設置較高，具有完美的鏡面反射率，為1.0，但大多具有反光塗層的材料應具有較低的值，這就是為什麼默認值為0.1的原因。

Perpendicular Reflectivity側向反射

This controls the strength of reflections when viewed at a 90 angle from the surface. In keeping with the Fresnel effect, this should always bet set to 1.0 so that reflections will be stronger when viewed at shallow angles.

當視角與表面法線成90度時的反射率。根據菲尼爾效應，該選項應始終設為1.0，使反射率在淺視角時更強列。

If the Facing and Perpendicular values are the same, then the Fresnel effect will be disabled and there will be equal reflection, regardless of viewing angle.

如果Facing和Perpendicular值相同，不再有菲尼爾效應，無論何種視角反射率相同。

Curve Factor過渡參數

This controls how the facing and perpendicular reflected strength transitions between one and the other. Higher values produce a 『tighter』 transition.

用於控制正向與側向反射率的過渡曲線的變化程度。數值越大，過渡越劇烈。

Metallic Flakes金屬碎片

Reflection General總反射

Color顏色

This is the color of the flakes. Since the flakes are embedded inside the pigment

layer, they will also take on the color of the pigment.

該顏色為金屬碎片的顏色。由於碎片被嵌入在底層層中，因此它們也會加入底漆顏色。

Weight權重

This is a multiplier that scales the amount of reflection that can be received. For

correct energy conservation, this should be less than 1.

該選項為倍增器，用於縮放採樣的反射強度。為了保護能量守恆，其設置不應大於1.

Glossiness光澤度

High glossiness means sharp reflections. Lower numbers will make the reflections

blurrier. Metals typically have low glossiness.

光澤度高說明反射清晰。參數設置越低，發射越模糊。金屬通常具有較低光澤度。

Samples採樣

This controls the number of ray traced samples required for the glossiness. A value of 0.0 means 1 sample, with perfect specular reflection. The 『rougher』the coat, the more samples you will need to get rid of noise. Also be aware that the more samples you use, the longer it will take to render.

採樣數量。數值為0，適用於完美的鏡面反射採樣。塗層越「粗糙」，為消噪所需的採樣越多。另外請注意，使用採樣越多，渲染所耗時間越長。

Highlights Only僅採樣光源高光

This optimization option will disable indirect reflection ray tracing of the environment and just capture specular reflections from lights.

該優化選項將禁止採樣環境中的間接反射，並只採樣光源，用於產生鏡面發射高光點。

Fresnel Reflection Control菲尼爾反射控制

Facing Reflectivity正向反射率

This controls the strength of reflections when viewed head on, 0 degree angle from

the surface. The values range between 0.0 and 1.0. Typically, metals will have a high setting, with a perfect mirror being 1.0.

Perpendicular Reflectivity側向反射率

當視角與表面法線成90度時的反射率。根據菲尼爾效應，該選項應始終設為1.0，使反射率在淺視角時更強烈。

Curve Factor曲線因素

This controls how the facing and perpendicular reflected strength transitions between one and the other. Higher values produce a 『tighter』 transition.

用於控制正向與側向反射率的過渡曲線的變化程度。數值越大，過渡越劇烈。

Definition清晰度

Density密度

This controls the density of the flakes, with lower values meaning sparser flakes.

該選項控制金屬碎片的密度，設置值越低說明碎片越稀疏。

Decay Distance衰減距離

This controls the distance at which the visible flake effect will decay to nothing. In reality on a very sunny day, flakes can be seen for several meters, so this should be tuned to match the lighting. A value of 0.0 means the flakes will always be visible. It is important to use this option, because as with any 『noisy』 effect, once it becomes sub-pixel it will look like an undesirable artifact.

該選項控制粉狀金屬質感衰減為零時的距離。現實中，在陽光燦爛的環境下，粉狀的金屬質感在幾米外可見，因此應根據光照條件調整Decay Distance。值為0時說明粉狀的金屬質感始終可見。該選項很重要，因為作為「噪點」的一種，一旦涉及採樣子像素，就可能產生不該出現在渲染中的缺陷。

Variation變化

This controls the flake orientation perturbation amount, with respect to the surface. A value of 0.0 means the flakes will have no perturbation and, essentially, have the same normal as the surface. Higher values yield a more noticeable flake effect.

該選項控制的金粉的擾動。0.0值說明薄片沒有擾動，也就是它們和表面具有相同的法線。值越高，金粉的反光區分度越高。

Scale比例

This controls the size of the flakes. Usually very small values should be used, around 0.005 to look realistic.

該選項控制金屬碎片的大小。通常，為看起來更加真實，應使用較小的值大約為0.005

Clear Coat Reflection透明塗層反射

Color顏色

This is the color of the reflection coat layer.

該顏色為表面塗層的反射顏色

Weight

This is a multiplier that scales the amount of reflection that can be received. For correct energy conservation, this should be less than 1.

該選項為倍增器，用於縮放反射的採樣強度。為保持能量守恆，其設置不應大於1.

BRDF

New to 2.0 Feature

Ashikhmin-Shirley (legacy)

Beckmann (Cook-Torrance)

GGX

Ashikhmin-Shirley

The legacy BRDF option uses a non-linear looking glossiness fall-off and exists to maintain compatibility with 1.0 materials.

Glossiness光澤度

High glossiness means sharp reflections. Lower numbers will make the reflections

blurrier. Metals typically have low glossiness.

光澤度高說明反射清晰，參數設置越低，反射越模糊。金屬通常具有較低光澤度。

Samples樣本

定義採樣數量。數值為0，適用於完美的鏡面反射採樣，塗層越「粗糙」，為消噪所需的採樣越多。另外請注意，使用採樣越多，渲染所耗時間越長。

Fresnel Control菲尼爾控制

Facing Reflectivity正向反射率

This controls the strength of reflections when viewed head on, 0 degree angle from

the surface. The values range between 0.0 and 1.0. Most materials with reflective coats, however, should have relatively low values, which is why the default is 0.05.

在視角與表面法線成0度，即從正面看時的反射強度。值的範圍在0.0和1.0之間。通常情況下，金屬參數設置越高，具有完美的鏡面反射率，為1.0。但大多具有反光塗層的材料應具有較低的值，這就是為什麼默認值為0.1的原因。

Perpendicular Reflectivity側向反射率

當視角與表面法線成90度時的反射強度。根據菲尼爾效應，該選項應始終設為1.0，使反射率在淺層視角時更強烈。

Curve Factor過渡參數

This controls how the facing and perpendicular reflected strength transitions between one and the other. Higher values produce a 『tighter』 transition.

用於控制正向與側向反射率的過渡曲線的變化程度。數值越大，過渡越劇烈。

Advanced高級

Enable Trace Depth Override

This enables the Max Reflection Trace Depth parameter.

When not enabled, the global trace depth will be used.

Note that when enabled, the override cannot exceed the global trace depth.

Max Reflection Trace Depth最大反射跟深度

This parameter controls the trace depth for reflection rays shot from this material. If the reflections of a material are not very defined (meaning: they are blurry because of the glossiness parameter or have a low weight), then multiple reflection bounces can be a waste of rendering time. This parameter allows the user to reduce the trace depth and speed up rendering.

該參數控制從該材料中所發出採樣射線的跟蹤深度。如果反射效果並不是很明確（由於光澤度設置或由於權重較低），多次反射反彈可能會浪費渲染時間。該參數允許用戶減少跟蹤的深度並加快渲染。

Cut-off Override Enable開啟強制剪切

This parameter allows you to override the global cut-off setting for reflections.

該選項用於覆蓋全局反射的Cur-off設置。

Cut-off Override Threshold強制剪切閾值

When the reflections of a material are very dark (because of low 「Weight」 or 「Color」 values) they contribute very little to the final image. This parameter defines what is considered 「very dark」 at which point no more reflection rays will be shot - which will speed up rendering. Scenes containing very strong lights might need this parameter set to very low values such as 0.0001 in order to avoid early termination of tracing which can produce a grain-like effect.

當反射效果非常黑暗時（由於「權重」或者「顏色值較低」），他們對最終圖像作用較小。這個參數定義了什麼是「非常黑暗」，在這種情況下不再發出反射採樣射線------這將加快渲染。帶有強光源的場景可能需要將該參數設置為非常低的值，如0.0001，以避免提前終止採樣導致的顆粒效果。