Thanks for your help ... I finally set a fake emitter material.

thanks for your reply, but I'm using a self-made component which modelize a builting spotlight. So I can't cut the intersection beetwen the ceiling and the KT spotlight. I realy want to keep the KT spotlight into my component to easly change the position of the object.
So I set a KT pointlight additionnaly of the KT spotlight, 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.

My testing project

My spotlight component

Hi everyone, I'm french user and English is not my speciality so sorry for mistake.

My trouble deal with the render into Kerkythea of my scene including spotlight ; which are KT spotlight component.
So as you can see in the picture below, the spot is lighting but not the hot point of the spot (where is the bulb).

So how can I set it lighting like a real one ?

Ok thanks for your reply, its exactly that because my model is 3mm radius and 10mm for the height.

So a trying bigger (300 radius and 1000 height) and there's no probleme.

Thanks again for your reply and your speed

Hi, first excuze me for my english, I'm french user ;

I'm trying to make a screw by following this tutorial on YouTube : http://www.youtube.com/watch?v=IT5r3AQZBnw
But I don't have the same behavior when I explosed the bolt to merge with the cylinder ... some faces disappears and I don't know why.

I know there many way to realize a screw, but a like the simplicity of this one if a find the way to keep all faces appeared.

So if someone know why a got this behavior and how to solve it ?