Important: The Built-In Render Pipeline is deprecated and will be made obsolete in a future release.
It remains supported, including bug fixes and maintenance, through the full Unity 6.7 LTS lifecycle.
For more information on migration, refer to Migrating from the Built-In Render Pipeline to the Universal Render Pipeline and Render pipeline feature comparison.
The Custom Data module allows you to define custom data formats in the Editor to be attached to particles. You can also set this in a script. See documentation on Particle System vertex streams for more information on how to set custom data from a script and feed that data into your shaders.
Data can be in the form of a Vector, with up to 4 MinMaxCurve components, or a Color, which is an HDR-enabled MinMaxGradient. Use this data to drive custom logic in your scripts and Shaders.
The default labels for each curve/gradient can be customized by clicking on them and typing in a contextual name. When passing custom data to shaders, it is useful to know how that data is used inside the shader. For example, a curve may be used for custom alpha testing, or a gradient may be used to add a secondary color to particles. By editing the labels, it is simple to keep a record in the UI of the purpose of each custom data entry.