- Qt 6.9
- Qt Quick 3D
- QML Types
- QtQuick3D.Particles3D
- ParticleSystem3DLogging
- Qt Quick 3D | Commercial or GPLv3

# ParticleSystem3DLogging QML Type

Provides information of the particle system. More...

Import Statement: | `import QtQuick3D.Particles3D`
Since: | Qt 6.2

- List of all members, including inherited members

## Properties

- loggingInterval : int
- particlesMax : int
- particlesUsed : int
- time : real
- timeAverage : real
- timeDeviation : real `(since 6.3)`
- updates : int

## Detailed Description

The `ParticleSystem3DLogging` type provides information about particle system statistics. This element cannot be created directly, but can be retrieved from a ParticleSystem3D.

## Property Documentation

loggingInterval : int

This property defines in milliseconds how often the logging data is updated. Longer update time increases the accuracy of time and timeAverage, while shorter update times keep the data more up to date.

The default value is `1000`.

particlesMax : int `[read-only]`

This property holds the maximum amount of particles in this system. Maximum amount is the sum of system particles maxAmount properties.

particlesUsed : int `[read-only]`

This property holds the amount of particles currently in use in this system. This value should be close to particlesMax at some point of particle system animation. If it is much smaller, consider decreasing maxAmount values. If it reaches particlesMax, particles are used effectively but it can also mean that particles are reused before they reach the end of their lifeSpan. In this case, consider increasing the maxAmount values.

time : real `[read-only]`

This property holds the time in milliseconds used for emitting and animating particles in each frame.

timeAverage : real `[read-only]`

This property holds the average time in milliseconds used for emitting and animating particles in each frame. Average is calculated from the middle 50% of the past max 100 logging updates. So when loggingInterval is 1000, this represents an average time in past 100 seconds. This can be used for measuring the performance of current particle system.

timeDeviation : real `[read-only, since 6.3]`

This property holds the deviation of the average times in milliseconds. The value is the difference between maximum and minimum values of middle 50% of the results, also called interquartile range (IQR). Bigger deviation means that the times fluctuate more so timeAverage can be considered to be less accurate.

This property was introduced in Qt 6.3.

updates : int `[read-only]`

This property holds the amount of particle system updates since the last logging. When loggingInterval is 1000 (default), this can be considered to match the fps.