OSL - 秒客网

1，SimpleColorShader:

shader gamma(color cin = color(,,),output color Cout=color(,,))

{

    Cout = cin;

}

Katana启动时候会自动编译:

OSL

Arnold里bin文件夹里有oslc编译osl文件。但是在centos的GLIB不是2.14,所以单独运行不行。但是在Katana启动调用时候为何自动编译，猜测是Arnold bin文件夹里已经把GLIB2.14一些符号编译成静态库了。

如果需要手动编译osl.编译GLIBC2.14.

编译glibc2.14 放到/opt/glibc-2.14

cd build

../configure --prefix=/opt/glibc-2.14

make -j

make install

#如果编译错误:

cp /etc/ld.so.conf /opt/glibc-2.14/etc/

再创建个bash文件调用GLIBC2.14,然后执行oslc,起名为:run_oslc

#!/usr/bin/env bash

GLIB_LIB_PATH=/opt/glibc-2.14/lib

KTOA_ROOT=/opt/solidangle/KtoA-2.2.0.2-kat3.-linux/

export LD_LIBRARY_PATH=${GLIB_LIB_PATH}:${LD_LIBRARY_PATH}

exec "${KTOA_ROOT}/bin/oslc" "$@"

则编译shader是:./run_oslc gamma.osl

Katana要加载osl shader 必须:export ARNOLD_PLUGIN_PATH=/mnt/Proj_Lighting/RD/katana3_plugin/Arnold/OSL_Shaders 要指定这个环境变量,

把shader放到这个里面，Katana会自动编译这些oslshader，不用自己去手动编译

2,添加辅助信息：

shader gamma[[ string help = "Simple mat" ]]

(color cin = color(,,)[[string help="InputColor",float min = , float max = ]],output color Cout=color(,,))

{

    Cout = cin;

}

3,Diffuse with noise

#include <stdosl.h>

shader SimpleShader(

    color diffuse_color = color(0.6, 0.8, 0.6),

    float noise_factor = 0.5,

    output closure color bsdf = diffuse(N))

{

   color material_color = diffuse_color * mix(1.0, noise(P * 10.0), noise_factor);

   bsdf = material_color * diffuse(N);

}

bsdf默认是个diffuse材质，下面只是乘以一些颜色

4,Metal Reflection

#include <stdosl.h>

shader GOSL_Metal(

    color diffuse_color = color(0.6, 0.8, 0.6),

    output closure color bsdf =)

{

   bsdf = diffuse_color * reflection(N);

}

OSL

diffuse(N):

OSL

5,Depth Color Channel:

#include <stdosl.h>

shader GOSL_Metal(

    float divide_value = ,

    output color bsdf =[[float min=,float max=]])

{

   point camera;

   camera = transform("camera","world",point(,,));

   bsdf = sqrt(dot(camera-P,camera-P))/divide_value;

}

OSL

6,Noise shader:

#include <stdosl.h>

/*

Coding Time:2018/9/10

liuyangping207@qq.com

*/

vector getNoise(vector inputPos,float amp,vector offset,vector freq,int turbulence, float rough){

    vector fp = ;

    vector sum=;

    vector sample_p = (inputPos + offset) * freq;

    float contrib = ;

    for(int i=;i<turbulence;i++)

    {

        vector ns = snoise(sample_p);

        sum += ns*contrib;

        sample_p *=2.6;

        contrib *= rough;

    }

    fp += sum*amp;

    return fp;

}

shader GOSL_Metal(

    vector inputPosition = ,

    float amplitude = ,

    float roughness = 0.55,

    int turbulence = ,

    vector offset  = ,

    vector frequency = ,

    int useRestNoise = ,

    output color bsdf =)

{

   if(useRestNoise)

    bsdf = getNoise(inputPosition,amplitude,offset,frequency,turbulence,roughness);

   else{

    bsdf = getNoise(P,amplitude,offset,frequency,turbulence,roughness);

   }

}

OSL

7,metadata in katana

#include <stdosl.h>

/*

Coding Time:2018/9/10

liuyangping207@qq.com

*/

#define OPTION_A 0

#define OPTION_B 1

#define OPTION_C 2

shader TestCode(

    int booleanvalue =  [[ string widget = "boolean" ]],

    int enumvalue =  [[ string widget = "popup", string options = "OptionA|OptionB|OptionC" ]],

    output color cout=

    )

{

    if (booleanvalue)

        cout=color(,,);

    if (enumvalue == OPTION_B)

        cout=color(,,);

}

OSL

8,Bounding obj color:

#include <stdosl.h>

/*

Coding Time:2018/9/10

liuyangping207@qq.com

*/

int zero_compare(float a ) {

    return a >= -0.00001 && a <=  0.00001;

}

float fit(float var, float omin, float omax, float nmin, float nmax) {

    float d = omax - omin;

    if (zero_compare(d)) {

        return (nmin + nmax) * 0.5;

    }

    if (omin < omax) {

        if (var < omin) return nmin;

        if (var > omax) return nmax;

    } else {

        if (var < omax) return nmax;

        if (var > omin) return nmin;

    }

    return nmin + (nmax - nmin) * (var - omin) / d;

}

shader TestCode(

    output color cout=

    )

{

    point Po = transform("object", P);

    point rbound[];

    getattribute("geom:objbounds", rbound);

    point pmin = rbound[];

    point pmax = rbound[];

    float bx = fit(Po[],pmin[],pmax[],,);

    float by = fit(Po[],pmin[],pmax[],,);

    float bz = fit(Po[],pmin[],pmax[],,);

    cout = color(bx,by,bz);

}