Configurable transition time for Matter lights

[FunFair]

I would like to request support for configuring the native Matter transition time when controlling Matter lights from Domoticz.

I am using a Matter-compatible IKEA smart light:
- IKEA KAJPLATS E27 WS globe 1521 lm
- Connected locally via Matter (OTBR + Matterserver.js)
- Domoticz is using its Matter integration
- The Matter device itself supports transition times

The transition functionality has been tested directly through the Matter Server and works correctly. When a transition time is supplied to the Matter device, the light performs a smooth transition between the old and new brightness/color temperature.

When controlling the light through Domoticz, I would like to specify a transition time when changing the brightness and/or color temperature.
Looking at the current Domoticz Matter implementation in hardware/Matter.cpp, Domoticz uses the Matter commands:
- MoveToLevelWithOnOff
- MoveToColorTemperature

However, the Matter transitionTime parameter is currently set to 0.
The IKEA light is capable of performing a native smooth transition, but Domoticz currently does not expose a way to configure the transition time for these commands.

Requested feature:
I would like Domoticz to support an optional transition time when sending Matter lighting commands or have a setting per lightbulb where you can define the transition time in 0.1s.

Ideally this should be available from the Domoticz API/dzVents as well, so a script could do something like:
set brightness to 50% with color 100 and a transition time of 2.0 seconds

This would allow Matter lights to use their native transition functionality instead of having to simulate transitions in dzVents by repeatedly changing the brightness in small steps.

[waltervl]

Is that a new function in Matter? As I know in Zigbee you can set the transition time parameter per device in the Zigbee controller UI (eg Zigbee2MQTT or Z4D) with parameters. I am not aware you can set transition times in Zigbee per on/off command.

[FunFair]

Is that a new function in Matter? As I know in Zigbee you can set the transition time parameter per device in the Zigbee controller UI (eg Zigbee2MQTT or Z4D) with parameters. I am not aware you can set transition times in Zigbee per on/off command.

I think so. In my matter server I can view the settings but cant alter. There is a test function where I can enter a light value and transition time and that works. So it seems to me that it is a parameter. I dont know if its possible to test?

See screenshot:
https://www.dropbox.com/scl/fi/5lloyho3 ... 91j1f&dl=0
https://www.dropbox.com/scl/fi/gabicyb5 ... 36b9m&dl=0