VRay Base
VRay Base
这是一个个人研究笔记,原创
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VRayMtl
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基本类
漫反射(150/127)、粗糙度
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反射类
反射类、金属类(亮光陶瓷、金属)
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低光泽度影响(哑光陶瓷、哑光金属)
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关闭菲涅尔+12低反射(反射与第一类效果类似,金属效果依然是反射溢出再限制、得到错误结果)
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关闭菲涅尔影响
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无反射金属(一般边缘反射最强处应该白光,无反射时边缘“反射了黑光”,得到错误结果)
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菲涅尔反射率(默认1.6且被锁不可调节)
(待测)
实验:反射与光泽度,结论:反射与光泽度共同决定反射效果
00,10,01,11
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小结:分析 & 理论
反射过程假设 —— 先吸收后反射原则
吸收:吸收的大部分【非固有色光】、反射小部分【固有色光】
反射:吸收光达到【某个阈值】后,吸收【反射色光】的能力下降到比吸收【固有色光】的能力还弱,【反射色光】被大幅反射
这里我定义这个【阈值】为【强光/高光阈值】
材质类型本质
【一般】吸收光、不反射光(阈值极大)
【反射】吸收光、反射光(阈值后)
【金属】不吸收光、反射光(阈值为0)
【不存在】不吸收光,不反射光
注1:上面的“不”是相对而言,非绝对意义上的。绝对吸收光是绝对黑体,绝对反射光是绝对镜面
注2:这里分析的是不透光材质、透明材质是不吸收光不反射光的
结论体现 —— 反射与金属
吸收光和反射光共同作用,体现为:
【反射】本质:开启后把高光阈值从极大值变为较小值
弱光区反射的【固有色光】更多,体现为【固有色光】
强光区反射的【反射色光】更多,高光区体现为【反射色光】(实际上更类似于反射色与固有色的混合色)
【金属】本质:开启后把高光阈值变为近乎零
由于无吸收光,阈值为零,近乎全部区域体现为强光区,体现为【镜面反射】
菲涅尔效应影响的边缘区域反射强,体现为【反射光色】????
自身反射区,则在镜面反射的基础上多次吸收【非固有色光】,不断放大了吸收程度,使其区域变为吸收光特性、又因是弱光,体现为【固有色】,而并未是由于其光强弱于阈值的原因,而且此处的光强未必最弱
结论体现 —— 光泽度参数影响
旧版VRay3反射光泽度与高光光泽度的结合,也称为反射模糊
【光泽度影响】本质:不影响高光阈值,变弱高光区亮度
由于直接反射变为表面散射,所以强光区区域变大,强度变弱。阈值不变的情况下让强光区的亮度更难以达到阈值
结论体现 —— 菲涅尔反射参数影响
【菲涅尔】本质:减弱反射、同时有菲涅尔反射效应
注1:关闭菲涅尔除了会关闭效果外还会大幅提高反射效果,不能直接关
注2:关闭菲涅尔和金属度赋予不能同时操作,有Bug
金属下:不能关菲涅尔,不讨论错误结果。在旧版VR3没有金属度参数时常关闭菲涅尔来模拟金属
反射下:边缘可以看到变化,有菲涅尔时边缘反射强、出现一条颜色边
折射 —— 特别要注意的是:在法线反转区、反射变黑色、而折射会呈现特殊效果
默认:折射拉满、光泽度1.0、IOR1.6
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光泽度(0.5-0.9)、IOR(1.01-0.75)、光泽度+IOR
一般常用:空气1.0,水1.33,玻璃1.5~1.6(注:勿作科学用途)。光泽度小了可看作折射模糊、有点像磨砂玻璃的感觉,影响渲染速率
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线扫描 —— Blinn-Phong
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基本类
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反射高光类
高光(100)、光泽度影响(80)、柔化影响(1)、光泽度 + 柔化影响
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基本类 —— 这里要注意一下扫描线和VRay渲染的区别:对于法线反转VRay默认呈黑色,而扫描线呈背面消隐
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反射高光类(Blinn-Phong)
高光(100)、光泽度影响(80)、柔化影响(1)、光泽度 + 柔化影响
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反射高光类(10%光线追踪)
其他反射高光参数作用不变,起叠加效果
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小结:分析 & 理论
【高光】
高光控制高光区的有无,相当于VRay的反射
【光泽度】
光泽度控制高光区的,相当于VRay的光泽度(扫描默认光泽度0.1,VRay光泽度默认1.0)
【柔化】
低光泽度时不起作用,可以推测柔化是对光泽度的处理
能柔化、弱化高光