Atmospheres matching a model

buggs_moran · Post #1by **buggs_moran** » 04.02.2007, 05:05

A while back I saw an atmosphere wrapping a model, i.e. it was non spherical. Is there something special I have to do to achieve this?

Post #2by **selden** » 04.02.2007, 15:09

Not so far as I know. What you see is what you get.

Chris has written that he needs to work on how atmospheric effects are drawn around Meshes. I don't know what progress there has been, though.

Post #3by **chris** » 05.02.2007, 07:33

There's nothing special that you do, though you probably won't get quite the effect that you want right now. For one, the shape of the atmosphere volume has to be an ellipsoid. I've no plans for arbitrary shaped atmospheres, because it would involve a lot of coding work to create something that's not even realistic.

However, if an ellipsoidal volume around an irregular mesh is all that you need, then you can just use a normal atmosphere. There's one caveat--the falloff in density is assume to start at radius of the object's bounding sphere and not the center, which isn't ideal for some possible usages.

--Chris

buggs_moran · Post #4by **buggs_moran** » 05.02.2007, 21:44

chris wrote:For one, the shape of the atmosphere volume has to be an ellipsoid. I've no plans for arbitrary shaped atmospheres, because it would involve a lot of coding work to create something that's not even realistic.

Huh? What about this mesh atmosphere... Also, what are the plans for the cmods with volumetric point sprites. Or, for that matter, any way to do a diffuse glow (that isn't an atmosphere). Any progress for 1.5? I know those mountains keep calling you Chris...

chris wrote:I just got atmospheres working for meshes . . . The only realistic usage is for modeling planets with meshes that are displacement mapped spheres, like some of the work by cartrite and others. Also, I'll probably improve the appearance of comet tails with a technique that uses the new atmosphere code.

--Chris

starfleetengineer · Post #5by **starfleetengineer** » 07.02.2007, 05:05

buggs_moran wrote:
chris wrote:For one, the shape of the atmosphere volume has to be an ellipsoid. I've no plans for arbitrary shaped atmospheres, because it would involve a lot of coding work to create something that's not even realistic.

Huh? What about this mesh atmosphere...

Looks like an ellipsoid to my eyes. :wink:

buggs_moran · Post #6by **buggs_moran** » 07.02.2007, 13:41

OK, I can see that. But, it hugs the object without any funky spherical ring around the mesh.

Chris, if you read this, could you post the atmosphere code for that object?

Post #7by **chris** » 07.02.2007, 18:18

buggs_moran wrote:OK, I can see that. But, it hugs the object without any funky spherical ring around the mesh.

Chris, if you read this, could you post the atmosphere code for that object?

It appears that I've deleted it . . . It's won't be much trouble to recreate it, but I think you'll be disappointed in current limitations of the technique. I intend to add an extra parameter for atmospheres that will help, but there's some other atmosphere work to be done first.

--Chris

buggs_moran · Post #8by **buggs_moran** » 07.02.2007, 18:59

I can be patient Chris, I know how much work you're putting into it. Frankly I'd rather see the work done on the atmospheres. And, since I just can't seem to say it enough, the possibility of volume diffusion that doesn't rely on a body...