The objects in this group can be used to modify particle properties. Individual properties, such as the Velocity, Color or Radius of the particles, can be set to a new value or relationships between properties can be created. For example, you can link the Age of the particles to a color gradient so that the colors change automatically depending on the life cycle of a particle. You can also influence new properties here, such as the relationship of a particle to its neighbors or other objects.
Modifiers can be applied across the board to all particles if they are placed directly on the top level of the scene, for example, or can be restricted to certain particles if they are sorted under a Particle Group. However, you have the greatest possible control if you group Modifiers under Conditions, as these can specifically filter out the particles on which a modification should have an effect. You will find a few examples below. For general information on using the particle system, you can find an introductory page here.
In this example, we use two Data Mapper Modifiers directly under a Particle Group. The upper Modifier establishes a link between the distance traveled by each particle and its velocity. This results in a rhythmic acceleration and deceleration of the particles. The second Modifier establishes a link between the speed of the particles and their radius. The Data Mappers used here are always very suitable if you want to use a particle property to control another property in order to create dependencies. The result can be seen in the following video.
In this example, we use two Emitters. One of the two emits many blue particles, the other a few red particles. We can make these two Particle Groups react to each other using a Predator Prey Modifier. The red particles chase the blue particles and the blue particles flee from the red particles. If a prey particle comes too close to a predator particle, it automatically becomes a predator and takes on its color. For example, the spread of infections or impurities in liquids can be visualized. We use an additional Condition to query the percentage age of all particles and then use a Math Modifier to gradually reduce the Radius value for each old particle. Because the Predator Prey Modifier and the Condition are directly at the top level of the hierarchy, they will automatically have access to all Particle Groups. The result can be seen in the following video.
In this example, we use several Emitters, but they all emit into the same Particle Group 1. This is also possible, e.g., to create more irregular areas with several Basic Emitters. There is a Collide Modifier within this group. This allows the particles to automatically collide with objects that have a Collision Tag. In addition, the particles can be automatically moved to another group in the event of a collision. In this second group, we also use the Collide Modifier again, but this division of the groups also gives us the option of configuring different rebound behavior, for example. Using an additional Surface Attract Modifier, we will simulate an attractive force between the objects and the particles in order to simulate a slow slipping of the particles on the sphere. A Field Condition helps limit this effect to the upper part of the sphere and to allow the particles to drip off in the lower part of the sphere. A Flock Modifier and a Gravity Force are on the upper hierarchy level and therefore have access to all Particle Groups. This gives us a force that permanently pulls the particles down and the Flock Modifier can be used to clump the particles together to simulate a syrupy consistency. A possible result can be seen in the following video.
