OTOY Forums

Hello,

I have been trying to find some help on how to use emission and emission ramp in the volume medium. If anyone has a tutorial or can help. I would like to try to make a nebula in a starfield. I can't seem to find any info on how to use emission in the volume medium for this purpose. I'm hoping someone can point me in the right direction to get me started. Thank you very much!

From what I've seen, you'll need an actual VDB file to get access to the kind of Emission Mapping you probably want for a nebula. As far as I can tell, a simple Volume object won't do it. Take a look at the second half of this to get an idea of how emission mapping of VDBs works:

https://www.youtube.com/watch?v=eh3qG0JpMuE&t=892s

There are lots of free VDB files out there to experiment with while you're getting started. If you want a free VDB generator to make your own, you can try the free version of Houdini, or various paid particle/volumetric tools can generate them, like X-Particles and Real Flow.

Good luck!

(Edit) I just realized that we are still using 4.x here in our shop, and there have been a lot of volumetric rendering updates in V 2018, and 2019, so take what I said with a big pinch of salt.

Thank you so much for the reply and tutorial link. i will definitely check it out!. I got some nebula-adjacent looks with emission (still not sure about the ramp though) but the light from the emission is showing the outline of the volume container, im not sure how to manage that

Hi,
check to have the same Volume Step length value in the Volume Medium node, for both the overlapping .vdb files.
ciao Beppe

Thank you, I will try that!