I'm understood, thank you.
As for the use of a single cloud layer. If you manage to figure out the heights and set up a single farctal on the density input of a single cloud layer - you can save a lot on render time. My current nebulae are realized in one cloud layer.
As for the stars. I realized the luminous stars in the 3D TG space. They are rendered in TG at the same time as the nebula. They can be an overlapping nebula in a natural way.
[attachimg=1]
For this, in fact, it's enough to send a fractal, similar to this (
https://planetside.co.uk/forums/index.php/topic,19264.0.html) to the density input of cloud layer v3. But I used the Voronoy to make the stars round. The luminescence is achieved with the help of the ambient input of the cloud layer.
Moreover, it is possible to achieve that the nebula itself is illuminated only by these stars! Above the nebula is illuminated by light sources. And so it looks like a nebula illuminated only by procedural stars:
[attachimg=2]
But there are two problems:
1) Each new rendering is a new stars. This is corrected by increasing the size of stars or increasing the setting of AA
2) The number of stars increases near the nebula. And the reason is not that the fractal for cloud adds color to the fractal of stars. I think this is due to an increase in the accuracy of calculation around the nebula.