I heard a lot of good comments about Lumion.
Can we use it as a SketchUp extension or as a separate software? It is not cheap, about $1,300 per year.
Thank you.
It’s separate software. Bur there is a live sync between SU and Lumion. Read more about it here: https://support.lumion.com/hc/en-us/articles/360007502894-Download-Lumion-LiveSync-for-SketchUp
There are better options like D5 that even has a free commercial license, Twinmotion that costs $300 per year or enscape that costs $550 per year, enscape is the only one out of those that works inside sketchup as a plugin, Twinmotion and D5 have live sync plug-ins though.
Lumion added ray tracing on their last version, D5 and Twinmotion have it for a couple years now, with Path tracer from twinmotion you can achieve very realistic renders.
Your profile doesn’t say but you need a powerful gpu to be able to use ray tracing on any of those rendering softwares.