Help with making earth shader in Maya

[RaeTracer]

Your shaders look pretty good... I think the earth color map needs to be a bit less blue. Some blue is good, to simulate atmosphere, but not too extreme. I haven't used the ramp shader much, I'm afraid, but for my earth I used a facing ratio shader on the atmosphere and it looked pretty good.

Here's a good tutorial on using facing ratio: http://www.thescratchpost.com/resources/tutorials/maya/candle/candle.shtml

Using set driven key on transparency, I made the atmosphere fade in from the edge, thickest and bluest around the edge of the earth, and then more transparent at the middle.

This guy has a useful tutorial on making the earth in 3D, and several of the maps you need. He has a cloud map at 2500x1250 resolution, too.
http://oera.net/How2/Earth1.htm

Good luck!

Here's my earth, by the way!

[NUKE-CG]

Hi,

I did a globe a few months ago for a background. Things you should do.

Unless you are using a dawn angle, like the sun slowly lighting the outer edge, then don't bump map, as you will not notice anything, as the extreme terrain differences cannot be seen in comparison to the huge sphere-like planet.

SpecularMap the land/ocean, as they have different reflectivity.

If you want the minor shadows that appear under the cloudes, use a raytraceShadow, and soften it a lot by increasing the Light Angle, but because of the increase angle - it will require more rays, so test it in 5s till you remove the noise.

Do the glow in post, AfterFX | Photoshop etc.. if you do not have access to them, you will be forced to use glows in Maya.
First turn off Auto-Exposure inside of the shaderGlow1 node, you will want to create:

*2D Ramp Texture.
*Sampler Info Utility.

Connect the Sampler Info's - Facing Ratio into the V Coord of the ramp, you my delete the 2dPlacement node, as the sampler info will assign the placement now, which will be based on the camera/object positions. Making the ramp black at the top, and the white colour underneath will tell Maya to use black for facing faces, and white as the outer edges of the earth, which are not facing the camera. Opening the Materials Special Effects tab, and then MMB drag-drop the ramp into the slot will connect the two. IPR render till you get the rim correct.

Use incadescence on you cloudes, a lot of light is bouncing around in them, the land should use the same colour map, but a lot darker for its incadescence, while the ocean should be fine because of its higher sheen (specular reflection).

BTW, NASA has huge resolution images available, google for them.. or maybe someone can post the address.

[RaeTracer]

Oh yeah, here's some HUGE images from NASA! You have to email them for the largest image (21,600 x 21,600 pixels) though.

http://earthobservatory.nasa.gov/Newsroom/BlueMarble/

[NUKE-CG]

Maya only supports 16k images anyway I believe, not a software limitation, but a 32bit cpu/os/program problem I think.

[Ultimatebadass]

Ok. Thanks for the tips NUKE-CG but there are a few problems.

I can't use maya's glow, because i'm rendering in mental ray (MR seems to ignore it). Normaly that wouldn't be a problem, but the software renderer gives an error message "memory exeption thrown" when i try to render. That is because of the textures i think: the earth maps are 8K (i also have a 10K set of textures, but with that even mental ray gives up) - i think it's due to my ram amount: only 512MB). Is there any workaround that error of Maya Software renderer?

It really doesn't have to be all that glowish - i only need the atmosphere to blend with the blackness of space more nicely.

Using incadescence on clouds causes them to be bright everywhere, even on the dark side of the planet (I used the reversed transparency map for incadescence). :(

I forgot to mention that i'm making that earth for my animation and i need to be able to render the whole planet. Incadescence made the clouds appear more realistic, but only in the area lit by the "sun". Can I make something similar as you did with glow, the ramp shader and sampler info, but making the incadescence level depend on the light position? (probably a stupid idea - but it's the only thing that came to my mind) The incadescence level is controlled by a texture so is it even possible?

Thanks for your help and sugestions :bowdown:

[RaeTracer]

I fooled around with that lightInfo node to try to get the effect you're describing, but nothing really came of it. For my animation, I did some compositing in After effects with three different layers: The render of the earth, clouds and atmosphere; the earth with a white lambert shader; the earth with a shader showing city lights at night. Then I composited them like this:

1. white earth (hidden)
2. regular earth - track matte set to "luma"
3. Night earth

This way, you get an animation where you can see the glow on the lit part of the earth, but the dark part is totally black with cool city lights on it. This was all in the maya renderer, though - I didn't use mental ray.

[Ultimatebadass]

Thanks RaeTracer! :beer:

I guess i'll have to fool around in After Effects a bit! I'll also have to look for some clouds maps that are bigger than 1024x512 because they just appear too blured (i'm guessing something ~4K would be enogh for them).

BTW: Your earth render is pretty good!

[JasonA]

While it is incredible tedious, one way to make better cloud maps, is to load your best ones in photoshop, and then create a second, ultra-hires blank image. use the clone tool and essentially re-paint the texturemap, duplicating as nessesary to have a higher-res cloud map.

you might have better luck with mr if you turned your maps into iff's or bots

[Ultimatebadass]

Thanks again for that Blue Marble site link! Finaly some decent cloud textures (8192x4096 is more than enough for me)!

Here is what I have now:

http://www.ffuniverse.pl/users/yogi/temp/earth_render_2.jpg

Still no glow though, but the textures and clouds look nicer (the incadescence did them good after darkening the texture map in photoshop, and those cloud maps also did their thing). Tomorow maybe i'll try rendering in 3 layers and adding some glow in After Effects just like RaeTracer sugested.

I tried to use the method described by NUKE-CG: sampler info thing with the ramp, but with no good results.

Thanks for all your help and if you have any more comments or sugestions how to make the image more realistic then please post ;)

[RaeTracer]

That's looking good! The atmosphere looks really nice, and the hi-res clouds make a big difference. I hope the After Effects technique works for you, too.! I'd like to see the renders of that.

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