 ), which controls the particle types to include and whether to render all particles or a subset of the particles. The Filter node has the following section:
), which controls the particle types to include and whether to render all particles or a subset of the particles. The Filter node has the following section:| • | All (the default) to include all rays. | 
| • | Primary to include primary rays only. | 
| • | Secondary to include secondary rays only. This includes the reflected rays released at material discontinuities. | 
| • | Logical expression to include a subset of rays that fulfills the logical expression that you enter in the Logical expression for inclusion field. For example, gop.I>1[W/m^2] only includes rays with an intensity greater than 1 W/m2, and x>0 only includes rays in areas where the x coordinate is positive. Click the Replace Expression (  ) button to select predefined expressions for the logical expression. | 
| • | All (the default) to render all rays in the ray tracing simulation. | 
| • | Fraction to only render a fraction of the rays. You specify the fraction as a number between 0 and 1 in the Fraction of rays field. The default fraction is 1; that is, to render all rays. | 
| • | Number to only render a certain number of rays, which you specify in the Number of rays field. The default is to render 100 rays. |