This module allows you to create particles that change size according to their speed in distance units per second.
This module is part of the Particle SystemA component that simulates fluid entities such as liquids, clouds and flames by generating and animating large numbers of small 2D images in the scene. More info
See in Glossary component. When you create a new Particle System GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary, or add a Particle System component to an exiting GameObject, Unity adds the Size by Speed module to the Particle System. By default, Unity disables this module. To create a new Particle System and enable this module:
Since this module is part of the Particle System component, you access it through the ParticleSystem class. For information on how to access it and change values at runtime, see the Size by Speed module API documentation.
For some properties in this section, you can use different modes to set their value. For information on the modes you can use, see Varying properties over time.
Property | Function |
---|---|
Separate Axes | Control the particle size independently on each axis. |
Size | A curve defining the particle’s size over a speed range. |
Speed Range | The low and high ends of the speed range to which the size curve is mapped (speeds outside the range will map to the end points of the curve). |
Some situations will require particles which vary in size depending on their speed. For example, you would expect small pieces of debris to be accelerated more by an explosion than larger pieces. You can achieve effects like this using Size By Speed with a simple ramp curve that proportionally increases the speed as the size of the particle decreases. Note that this should not be used with the Limit Velocity Over Lifetime module, unless you want particles to change their size as they slow down.
Speed Range specifies the range of values that the X (width), Y (height) and Z (depth) shapes apply to. The Speed Range is only applied when the size is in one of the curve modes. Fast particles will scale using the values at the right end of the curve, while slower particles will use values from the left side of the curve. For example, if you specify a Speed Range between 10 and 100:
You can specify how a particle’s width, height and depth size changes by speed independently. In the Size by Speed module, check the Separate Axes checkbox, then choose how the X (width), Y (height) and Z (depth) of the particle is affected by the speed of the particle. Remember that Z will only be used for MeshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
See in Glossary particles.