OSL - Open Shading Language

In this section you can find some OSL scripts I have written. OSL in Blender is used only with Cycles render and allows for a more versatile usage of the materials. To use them you must use cycles and paste the code into a script node.

- Laser Sheet
- Random Color
- Grid

Laser Sheet

This script was created to simulate a laser sheet illuminating the objects in a scene. You can find an example of a node setup and practical application here.

/*
 * DESCRIPTION:
 * Simulates the emmission of a laser sheet with origin in point (laserx, lasery, laserz)
 * and with a normal (norx, nory, norz)
 * The output variable, laserout, defines the strength of the laser, which should be 
 * connected to an emission shader, which is then added to the base material of the object.
 * The input parameters Thickness and Intensity allow the ajustment of the laser sheet.
 * High Intensity values might increase specle points

 * AUTHOR: written by Renato Sousa, 
 *         http://renatogsousa.weebly.com/
 *         email: renatogsousa AT gmail DOT com
 *         
 *         last modified 27 December 2012
 */


#include "stdosl.h"

shader pattern (
    float Thickness = 0.1,
    float Intensity=1,
    float laserx=0.0,
    float lasery=0.0,
    float laserz=0.0,
    float norx=0,
    float nory=0,
    float norz=1,
    output float laserout=0)
{    
    point Pos = P;
    int light=0;

    /* ***** plane definition ***** */
    vector lasernormal=normalize(vector(norx,nory,norz));
    float plane=lasernormal[0]*(laserx-Pos[0])+lasernormal[1]*(lasery-Pos[1])+lasernormal[2]*(laserz-Pos[2]);
    
    /* ***** light direction search: from point P to laser origin ***** */
    
    vector laserrelativepos=vector(laserx-Pos[0],lasery-Pos[1],laserz-Pos[2]);
    
    /* ***** limit the search distance to the distance between object and laser ***** */
    float maxdist=length(laserrelativepos);
    laserrelativepos=normalize(laserrelativepos);
    
    /* ***** trace if there is any object between point P and laser origin ***** */
    int shadow=trace(Pos, laserrelativepos,"maxdist",maxdist);
       
    light=(1-shadow);
    
    /* **** laser light is maximum in the plane, limited by Intensity **** */
    laserout=abs(Thickness / (plane))*light;
    laserout=min(laserout,Intensity);
}

Random Color

In this example, a random color node is created for every object, which can be the input for other nodes. Try to input it into a diffuse shader for example and duplicate the object to see what happens.


#include "stdosl.h"

shader RandomColor(
output float R=0.8,
output float G=0.8,
output float B=0.8,
output color RandomColor=0)
{
float Random=0;
getattribute("object:random", Random);
R=trunc(Random*100.0)/100.0;
G=trunc((Random*100.0-trunc(Random*100.0))*100.0)/100.0;
B=trunc((Random*10000.0-trunc(Random*10000.0))*100.0)/100.0;
RandomColor=color(R,G,B);
}

Grid

Here's a simple OSL script to simulate a grid, and the corresponding node setup. You can change the size of the grid with the freq. parameter, change its apparent thickness with Mag and displace it with deltax and deltay.

#include "stdosl.h"  
  
shader grelha(
    point Pos=P,
    float freq=10,
    float Mag=1,
    float deltax=0,
    float deltay=0,
    output float Fac=0,
    output float solido=0
    )
{
Fac=max(Mag*((sin(freq*(Pos[0]+deltax)))),Mag*((sin(freq*(Pos[1]+deltay)))));
solido=Fac>0;
}