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Old February 2nd, 2011, 11:30 AM   #1
evil_genius_180
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3 D CGI Tutorial: A Planet in Blender

I couldn't figure out if this is where we were supposed to post tutorials but one of the mods or admins can move it if it's wrong. A few months ago, I started messing around in Blender, which is far superior to what I've been using for years (trueSpace.) Chief among things I found to be superior are the materials and material settings. Among things to do in Blender was something that has always given me trouble in tS, a planet. So, I kind of followed a tutorial with some extremely blurry images to do this, though I had to guess/make up quite a bit of it. And, since I got it where I want it, I decided to make a tutorial for other people who want to do this. This tutorial was done in Blender 2.49.2, the latest stable version.

This is the planet:



Class-M if you’re a Star Trek fan, or Goldilocks (just right) planet, if you go by the NASA designation. Today, I’m going to show you how to do this.

Stuff you’ll need:

Blender 2.49.2 (you can use another version but that’s the one I used)

A basic understanding of Blender: I’ll be doing as little hand holding as possible here. I’m a Blender noob and I figured out how to do this by following another tutorial that was for an older version of Blender and had really bad reference images. You can do it too, considering that my images are at least readable.

Planet textures: Surface Color, Surface Bump, Ocean Mask, City Lights (optional), Cloud Color, Cloud Bump. I made my own planet textures but you can do a web search to find some, if necessary. Start with NASA’s website, in the 3D tool section, if you want some decent ones.

Part 0: Basic Setup

This is my setup, it’s very basic. I have a camera and two lights. The main light is the one on the opposite side of the centerline from the camera. It is set to 2.000 intensity and casts shadows. The “fill light” is to make the dark side a tad lighter, but really isn’t necessary, it’s a personal preference thing. It’s the light on the same side of the centerline as the camera and it’s set to 0.500 intensity and does not cast shadows.



Anywho, that’s my setup. You can do the same or just do your own setup, the choice is yours.

Part 1: The Surface

As with all parts, we start with a sphere. I added a UV Sphere at 100 x 100 segments, so that it’s nice and smooth. You can do whatever amounts of segments you want, though I do recommend going higher than the default 32 x 32, unless you want lightning fast renders, though my planet renders in just over a minute and 30 seconds at 1600 x 900. (running on (Linux) Peppermint Ice on a dual core @ 2.5GHz and 2GB of RAM) Anywho, the sphere settings:



I use these settings for ALL spheres, I won’t show it again.

Go into edit mode and hit “W” and select “set smooth” on the menu. Again, this is for ALL spheres, it won’t be mentioned again.

I scale my sphere up a bit but this is another personal preference thing. Next, apply a basic material to the sphere using the following settings:



Go to the texture buttons, add your surface map to the top layer.



Go back to the material settings, to the texture settings, under Map Input and hit the “sphere” button. This will be done for all textures, so it too won’t be shown again, though I will mention it. If your maps look FUBAR later on, make sure you refer back to this.



Leave the “Map To” tab alone for this texture, the default settings will work just fine.

In the 2nd texture slot, load your surface bump map.



Go back to the material settings and map it to sphere (like before) and this time, go to the “Map To” tab. Make sure you deselect the “Col” button and select the “Nor”button. Set the slider next to “Nor” (under the buttons on the right) to your desired bumpiness. I used 1.00, though for this distance, we really don’t even want any bump mapping but this is a full-featured tutorial.



Now, for the specular settings. If your planet surface doesn’t have oceans, you can really skip this step, unless you want specular highlights on the land (if you have oceans, you really just want specular highlights on them to make them pop.)

Go to the texture screen and load your ocean mask into the 3rd texture slot.



Go back to the materials section and make sure it’s mapped to a sphere and on the “Map To” deselect “Col” and select “”Csp.”



If you want to create a slight raise between the land and ocean, load the ocean mask into the 4th slot. As always, make sure it’s set to sphere and this time deselect “Col” and select “Nor.” Because it’s a straight black/white separation, make sure you only turn up the “Nor” slider a smidge, I used 0.10.



This concludes the Surface part of the tutorial. If you used the same settings I did, you should have something like this:



Part 01A: City Lights (optional)

For uninhabited planets, skip this. However, if you want your world to look like it supports a population, the best way to do this is by adding some city lights to the dark side. I have no idea how easy city light maps are to find on the internet but LunarCell generates them for me. (If you want to use LunarCell for Photoshop or Gimp, just search for it)

First, create a sphere, just a tiny bit larger than your original sphere. I like precision, so I do it by the numbers, using the control box that comes up when you hit “N” but you can just do it by hitting “S” for the scale tool, if you so desire. Anywho, the materials settings on the sphere are simple, just turn the spec all the way down and the emit slider all the way up and disable the shadows.



Go to the texture button and load your City Lights texture to the top slot. Set it to “sphere” and leave it alone.



In the 2nd texture slot, add the same texture. However, this time, with a twist. Under the texture layers, there is a group of buttons in the “map image” section. Select “CalcAlpha” This is VERY important.



Set it to “sphere” and go to the “Map To” tab. Deselect “Col” and select “Alpha” Also, hit the “Stencil” button.



Go back to your material settings, select “ZTransp” and slide the “Alpha” slider all the way to the left (to 0.000.)



If you’ve followed along with everything, it should look something like this:



Part 02: Inner Atmosphere

This part is really simple. You’re going to add some “inner atmosphere” haze to the planet.

Create a new sphere, slightly larger than the City Lights sphere. If you skipped the City Lights, make it slightly larger than the Surface sphere. Paint it blue with less spec (I used 0.250) and disable the shadows.



The next part is really simple. Press the “ZTransp” button and go under the “MirrorTransp” tab. Slide the “Fresnel” slider over. Notice how it makes the center of the sphere transparent, how much depends on the amount you use. I used 3.00.



That’s it for the Inner Atmosphere sphere. It should look something like this:



Part 03: Clouds

As always, make a new sphere, slightly larger than the Inner Atmosphere sphere. Turn the spec down some (optional.)



In the textures section, load your Cloud Color map. As usual, set it to “sphere” and leave everything else alone.



In the 2nd texture slot, load your Cloud Bump map.



Set it to sphere and under the “Map To” tab do the same thing we did with the surface bump, deselect “Col” and select “Nor” and slide the “Nor” slider to the desired strength.



In the 3rd texture slot, load your Cloud Color map again. This time, hit the “CalcAlpha” button, like you did for the City Lights, if you added City Lights.



Set it to “sphere” and go to the “Map To” tab. Like we did for the Cities, deselect “Col” and select “Alpha” and “Stencil”



Go back to the material settings and select “ZTransp” (if you didn’t already) and slide the “Alpha” Slider all the way to the right. For best results, also set the clouds to cast but not receive shadows.



If you haven’t said “Frack this” and gone to get a beer and a sandwich, you should have something like this:



Part 04: Outer Atmosphere (last part and it’s a quickie)

Easy way to do this, create a duplicate of your Inner Atmosphere sphere. You’ll get a sphere with the same material settings, just click “Add New” under materials, which will create a copy of the material and leave the one for the Inner Atmosphere alone. Make it slightly larger than the Cloud Sphere.



Go back to the “Fresnel” setting (under “Mirror Transp”) and simply turn down the Fresnel sot that you have a thinner band of “atmosphere”



This is my completed planet:



This was just a basic tutorial, to make a planet like I made mine. To customize yours, play with the bump, speck and Fresnel settings to get your desired look. You can also rotate your surface and cloud spheres to get different cloud and land configurations, but you might want to make the city lights a child to the land so that they rotate with it. Alternately, you can also move the camera and/or set up additional cameras to get different angles. It’s your planet, you can do what you want with it. Have fun.

Also, at present, I still don’t know how to do an atmospheric “glow” like you’d see if you got closer to the planet. Though, I am working on it.
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