Planet Creation:

5. Shader (Coming)

We have to make a ton of planets and moons for Star Trek. Currently around 300. But we don't want to create 300 unique planets jewelry-shopping each one. Therefore, we've done our best to create a texture and shader solution that will give us a lot of variety with a few basic source files. All of the source files SHOULD BE jewelry-shopped and inspired works of art because they will be used A LOT. In this tutorial I refer to a number of source files. The locations of these files will be covered in the folder structure section.

A planet is made of several components. For the sake of this document, let's deal with a class "M" planet. It has all of the components that we use on the planet shader. The shader combines many maps to create a planet. Parameters in the shader allow you to adjust the continents, colors of oceans, atmosphere, specular color, etc. There are a lot of options to give you the ability to make some great looking planets. We'll detail these texture channels below.

Continent Mask

The Continent Mask: If a planet has oceans and continents it has a continent mask. This mask is at the root of several other maps such as the City Light or Incandesece maps (you wouldn't have city lights in the ocean). It also allows you to modulate the color of the oceans and continents individually. The continent mask is also used in PhotoShop when defining ocean areas on the color map. Here's an example of a continent mask:

The Color Map: The color map defines the color. It is also modulated with gain and offset in Maya to create the specular map for the planet. The map is straightforward but creating the map takes some time. I've detailed this below. Keep in mind, each of the color maps will be used to create many planets. Here's an example of the color map:

Normal Map: Normal maps are straightforward. Be careful with them. If you abuse a normal map it tends to make the planet look too small and throws it out of scale. There is almost no depth descernable from space. Normal maps tend to work better on smaller celestial bodies such as moons. Here's an example:

City Light Mask: Believe it or not, the current planet shader supports city lights that only show up on the dark side of the planet. This map needs to be made for each continent mask as cities generally tend to be nearer these borders. Here's an example of the city light map.

Texture Creation:

When making the first planet texture map I tried to come up with a process that was very streamlined. The steps required to make this texture are as follows:

1. Choose overlays that look like a planet surface. For these overlays I get them from anywhere. I use asphalt, cracked paint, cement, rust, planets surfaces, whatever works. I desaturate them and work in greyscale at this point.Here's a few examples showing the raw files. All of these are in P4:

2. Combine these textures using overlay layer or soft and hard light. Look at cool planet surfaces and see what things look like. You want to have a lot of detail and this is an easy way to get it. Here's an example:

3. Use the paint bucket tool to select areas of your texture and randomly fill in these areas with colors that you think make sense for the type of planet you are trying to create. Use these colors as additional overlays using the mode of your choice. I find that desaturated colors look best but you can do that kind of tweaking as a final step. Don't worry about oceans at this point. Do that once you have a good terrain. It's an easy last step.

Here's an example of a planet surface all paint-bucketed up with oceans in place. I used one of the continent masks to create the ocean and just applied a layer style to give some interresting shore detail. You can see it's a little lighter around the edges. On this texture, note that I also put a bit of a highlight in the oceans around the equator. I just thought it made the planet look groovy. The planet texture was painted at 4096. That texture is on P4 at full resolution.

4. Clean up the seams. I'm going to be straight up with you, this is the pain part and I find it takes about an hour to do right. But once it's done, it's done. If there's a place in the pipeline for improvement, this is it. I made a photoShop action that did all my transformations (covered below) but it still takes time. There is a better way out there somewhere. Here's the UV layout:

Each one of those seams is pixel accurate and the overlap outside of the UV space guarantee's that, reguardless of in-game fuzzyness, there will be no seam. Right now, it's a manual process that can be explained in detail.

Mask Creation:

The mask creation process is something you can play with. Making them seamless is a chore. They need to work with the UV layout. Right now, we're pretty close but it takes some very minor cleanup.

The continent mask is the "Crater" 3D procedural shader in Maya. You can get many, many variations of continents by animation the place 3D node in Maya and rendering out each frame (Convert to file texture). You can also tune it to get the size and shape of the continents you want. Once you have the texture, adjust the levels in Photoshop to give you the crispness you want from your shorelines and clean up any seam issues that exist. Here's of a continent mask. The first image is raw out of Maya and the second is touched up in PhotoShop using levels and cloning the seams. The procedural file is on P4.

Folder Structure:

I set up a pretty extensive folder structure. Many of the textures are related so I set it up like a custom Maya project so when you were loading a mask file in Maya, it takes you to the right place. Once a planet is created, it can be saved out to it's correct sector (Epsilon, for example) and the textures can be referenced from the planet folder structure. Here's the structure and a description of what's in each folder:

Planets: This is the main folder.

Docs: I've put some documents in here that explain the process. There is also a tool spec in here in case this process is ever turned into one.

Texture Source: Here is where you'll find overlays, craters and images that I've collected that I think looks like planet stuff. Add to this. This is a start. The raw PSD files are here as well as the UV texture seaming guide.

Images: Standard Maya directory.

Reference: Throw cool planet reference in here so everyone can benefit.

Scenes: This is the scenes folder where you put finished planets. It's broken down by sector. Every planet has a specified name and belongs in a specified sector.

Textures: This folder contains finished source textures and is broken down into the categories that the shader uses.

Links:

Here are a bunch of links I found while researching planet creation. There a lot of good tutorials out there and some cool places to find images:

Planet Tutorial by Greg Martin. It's a good one.

Planet Tutorial

Advanced Planet Tutorial

Okay Planet Tutorial

Planet Resource Mostly our solar system.

Celestial Motherlode Great cloud textures here.

Our Internal STO Planet Info

Cloud Map: The cloud layer rotates above the other maps. Here's an example of the cloud map. We're going to need a lot of these.

Atmospheres: This is a shader parameter. Once you get in the and start playing you'll find it takes some tweaking. Here's the theory behind that:

Variations: This is a simplistic demonstration of the variations that are possible but I think it helps illustrate what we're going for. Check it out: