by Dean A. Scott5/8/11
This tutorial was written by Dean A. Scott who has graciously allowed us to host it here at Foundation3D.
It was originally written for LightWave 3D version 6 but should still be relevent to the current version.
So, you want to make a photo-realistic rendering of the Earth from orbit, eh? And you want it to look just like what astronauts see from the shuttle or ISS (International Space Station). No problem. Just follow these simple steps and you'll be there in no time. There's really nothing to the actual objects needed... there's just three highly subdivided spheres, each slightly larger than the other.
Note: We have included the objects, texture maps and scene files at the end of the tutorial.
In this tutorial, I'll be describing most of the whys of what I'm doing so you can apply these techniques to almost any other type of planet. Just a note, for orbital level points of view, which is around 200 to 250 miles in altitude, you'll need very high resolution images of the Earth's surface, topography, and clouds (on the order of 10,000 x 5,000 pixels) so that they don't become pixelated when rendered at these distances. For medium and long shots of the full disc of the Earth, images that are 2048 x 1024 pixels will do just fine.
There are a lot of Earth images at many different resolutions available on-line, so these images are not provided in the zip file above. James Hastings-Trew and NASA's Blue Marble sites have all that you need for 1K all the way to 10K resolution images
LET'S GET STARTED!
In Modeler, make a Sphere that's 127.6 KM in diameter with 96 sides and 48 segments. Use the Numeric input to enter these values.
This is 1/100th the size of our Earth. Using a decimal fractional value of the real thing allows for more precise modeling of the other two objects yet to follow.
Give this sphere a surface name of "Earth - Surface" and Save the object as "Earth-Surface.lwo"
Select the Size tool and its Numeric input and increase diameter by entering 100.2%, then clicking Apply. This enlarges the sphere so that the cloud tops are around 15 miles above the surface (relatively speaking, that is... the actual scale is 1/100th that in these models).
Close the Numeric input and give this object a new surface called "Earth - Clouds" and Save it as "Earth-Clouds.lwo"
Undo the changes to surface and size by pressing the 'u' (undo) key twice to get back to the original object. Now, Size up the sphere again, this time by 101.7%. Give it a new surface name of "Earth - Atmosphere" and Save as "Earth-Atmosphere.lwo"
This expands the sphere so that it extends about 120 miles or so (relative to the scale) which is where the atmosphere thins out to nothing (or there abouts, it doesn't have to be exact as shading this sphere will not be a precise science in achieving an exact maximum altitude for the end of the atmosphere anyway. Plus, the atmosphere always has a different look depending on the Sun's illumination angle and a myraid other factors that just can't be simulated in 3D. Some photos of the Earth from shuttle orbital altitudes show an extremely prominent limb, while others don't appear to have much of a fuzzy edge at all.)
That's it for Modeler. Close it and run Layout.
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