 ), 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 particles. | 
| • | Primary to include primary particles only. | 
| • | Secondary to include secondary particles only. | 
| • | Logical expression to include a subset of particles that fulfill the logical expression that you enter in the Logical expression for inclusion field. For example, pt.V>1 only includes particles with a velocity larger than 1, and x>0 only includes particles 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 particles in the particle tracing simulation. | 
| • | Fraction to only render a fraction of the particles. You specify the fraction as a number between 0 and 1 in the Fraction of particles field. The default fraction is 1; that is, to render all particles. | 
| • | Number to only render a certain number of particles, which you specify in the Number of particles field. The default is to render 100 particles. |