@toto85980 said: which I place into my spotlight component and behind the glass ; and I got the render I'm looking for, but the Kerkythea render take more time. I'll shared my skp component if you have any idea to perform my render ... I don't know how to set a fake emit light material on my object. [attachment=2:3tb4kf8q]<!-- ia2 -->spotlightsample.jpg<!-- ia2 -->[/attachment:3tb4kf8q] If you put a light behind the glass, glass will turn light to caustic light, that will render quite lot slower. Please read trough Kerkythea tutorials at http://www.kerkythea.net/forum/viewtopic.php?f=16&t=5720 They will guide you trough the basics.

Pilou often links from that Kitto Raup and that guy has some very good video tutorials mostly made with the native tools that we often neglect nowadays as we are overwhelmed and spoiled by those plugins. (Similarly, Jean Lemire often posts simple solutions achievable with the native tools instead of suggesting some "easy looking" way with plugins).