View Full Version : volumetric atmosphere

06-19-2003, 11:13 AM
I am trying to set up an atmosphere around a planet using a hypervoxel sphere around a Null that moves with the planet. I am having trouble surfacing it. I am using a solid hypervoxel but it seems that the atmosphere has to have some luminosity or it just makes everything black. The problem is, with luminosity set to some positive numver, it is making the atmosphere lighten up where it should not be recieving/emitting light i. e. the dark side of the planet.

I am trying to achieve a steamer like effect, but since there is no steamer any more, is this the way to go about it?

The book is very brief about how to use the settings on this tab!


06-20-2003, 12:31 AM
Have you tried applying a b/w texture to luminosity/ opacity? Also using a volumetric light for your atmosphere may be a better choice.


06-20-2003, 04:30 AM
You can do all that just using geometry: a sphere with luminosity with incidence angle, etc. Look for an Earth tutorial, there's several

06-20-2003, 09:28 AM
Yes, but doing it with geometry doesn't let you move through the stuff. I need to go down towards the surface and have it begin to make a "sky". I have something close, but it has a very hard edge. If the fog was really volumetric wouldn't you see less effect near the very edge of the sphere and more as you move the chord that the light is passing through toward the center?

06-20-2003, 05:25 PM
Try this


Very good results:D

06-21-2003, 07:56 AM
I already looked at that, he does it with geometry, and I cant use that to fly down to near the surface through the atmosphere. I have a decent atmosphere using a hypervoxel sphere, but it won't recieve the volumetric shadow from the planet inside, or more likely, It doesn't seem to be catching any light at all, it needs luminosity to show up, but that is no good because, as I said, the glow spreads all around to the dark side of the planet and looks like crap. I have enabled ray trace shadows on my "sun" distant light, but to no avail. Maybe I just don't get this voxel thing at all. I am trying to recreate the steamer atmosphere shown in the book, "Lightwave 3D Applied". Thanks for any insight!

06-21-2003, 02:11 PM
it doesn't surprise me that an hv sphere doesn't recieve shadows on it's inside - they're intended for drops of liquid, stretching it to a planet is pretty extreme - but that wouldn't have any more thickness than geometry, unless I misunderstand what you're doing

I still think it could be done with geometry, add some thickness or hv (volume) where the camera passes thru

06-22-2003, 12:00 AM
Here is an idea that might work using geometry. Have a sphere just inside the atmosphere sphere with the polys facing inward and then when you pass through it should be a seemless transistion.

06-22-2003, 12:39 AM
I acheived a very nice effect using the LW that comes with VT, using a series of concentric spheres. I imagine that if I dissolve the spheres as I get closer to the surface and likewise dissolve in some "inward" facing spheres as the camera goes down, It can be done. I just was hoping that by making my simulation reflect what happens in the real world I could save a lot of bother in the long run... I wish it was more straighforward. If the HV could recieve the shadow of the planet it would be the cheese! As it is, I face a nightmare unless someone out ther has a better plan

06-22-2003, 03:22 AM
I have attached a file using a volumetric light. This should get you going. All you need to do is tweak settings and add more layers if needed....


06-25-2003, 01:07 PM
Didn't have Ray Trace Shadows enabled in the render panel. D'oh! Now the hypervoxel's volumetric shadows are working right, but it really does kill the render time. :( Thanks for the help all. :)