Sign in to follow this  
FreJa

atmosphere glow

Recommended Posts

Hey, How can I achieve the atmospehere glow effect. Like in this pic: is there any non-shader way of achieving this? Thanks

Share this post


Link to post
Share on other sites
You might be able to encase your 3D objects in a slightly larger object, which is rendered counter-clockwise instead of clockwise. That way, all the polygon faces to be rendered face in, not out, and when you rotate around the object, you only see the overlap from the slightly larger image to the slightly smaller image. Then it's just a matter of getting the color, lighting, and shading correct.

Totally untested, unfounded solution, so take with a grain of salt if it doesn't work. If it does, send money. LOL

Share this post


Link to post
Share on other sites
you could also have a textured cone behind the planet, that rotates around the planet's origin as the camera is moving.

i.e

Viewdirection -> Camera ...... Planet..... Cone.

Share this post


Link to post
Share on other sites
Hi,

You creat a texture with a filled circle and then use say a gaussian blur or other blur in a paint package to get the falloff as you want it.

The create a quad that always faces the camera. If you ensure that it drawn first or simply position its axis at the planet objects centre and then scale the quad until the texture you made gets drawn outside the radius of the planet object.

The texture doesn't need to be very hi-rez as you can get the bilinear filtering to smooth it out.

That should work.

Hope that helps.

Share this post


Link to post
Share on other sites
Guest Anonymous Poster

take a look into atmospheric scattering

http://www.gamedev.net/reference/articles/article2093.asp
http://sponeil.org/

http://www.ati.com/developer/dx9/ATI-LightScattering.pdf#search=%22atmospheric%20scattering%20site%3Aati.com%22

Share this post


Link to post
Share on other sites
It all depends on how much realism you need and how much free time you have on your hands. If the answer to both is "lots" then go look up atmospheric scattering. This will quite likely involve shaders too for performance reasons (of course you can do anything on the CPU but it may not be wise).

If you just need something that looks reasonably good (or unrealistic but flashy in the arcade-ish sense), the cone method is adequate. I've used a cone with its point at the center of the planet, and the opening angle set so that the cone intersects the sphere at the horizon from the camera's point of view. Only the part above the surface is rendered, of course (producing a quad or triangle strip like a skirt along the horizon, and all of these polygons face the camera).

The reason I wouldn't go with the big quad is that it's not trivial to get it to look right with perspective, in particular when the camera is close to the planet.

Share this post


Link to post
Share on other sites
why a cone ???
a circle will suffice, just make it rotate in de same angles as the camera does (a billboarding effect )

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this