setSpotlight was called while no presentation is running, so nothing is dimmed. Start the presentation first, and note that stepping to a view clears the spotlight, so arm it after the deck has started rather than before.

Warnings reference › presentation.spotlight-inactive

Identifier

presentation.spotlight-inactive

Raised by

The grid (core)

Since

1.4.0

What happened

The spotlight dims everything but its target, and the painter only dims while a presentation is running. Called on a stopped grid it changes nothing on screen. Stepping to a view also clears the spotlight, so arming it before the deck starts has no effect either.

The fix

Start the presentation, step to the view you want, then set the spotlight.

Reference

Covered in full at the API reference.