{"id":834,"date":"2020-04-17T15:00:04","date_gmt":"2020-04-17T20:00:04","guid":{"rendered":"http:\/\/www.moroha.net\/blog\/?p=834"},"modified":"2020-04-17T19:06:52","modified_gmt":"2020-04-18T00:06:52","slug":"sci-fi-rpgs-and-rendering-planets","status":"publish","type":"post","link":"https:\/\/www.moroha.net\/blog\/archives\/834","title":{"rendered":"Sci-Fi RPGs and Rendering Planets"},"content":{"rendered":"\n

My bi-weekly RPG group has, like most now, had to move online to keep playing. Though to many playing pen-and-paper RPGs online has become the norm, we’re a bit older and more traditional so it was a first for all of us. But we’ve been using roll20.net and got it mostly figured out.<\/p>\n\n\n\n

Our group has been playing D&D5E, and the campaign is an older but well-known 2nd edition campaign called Night Below, which is a long campaign that takes place entirely in the Underdark. Right now we’re in the middle of the final adventure and it looks to wrap up in the next 1-2 sessions. With that we’ve been talking about what to play next.<\/p>\n\n\n\n

I’ve volunteered to take a turn DMing, and we’re going to try a sci-fi campaign using Stars Without Number<\/a>. As such I felt that I needed to get an adventure ready and start polishing my adventure\/campaign production skills. I really like making and using maps in my RPGs, and I noticed that ProFantasy<\/a> has put their excellent Campaign Cartographer software on sale for half price during the Covid-19 pandemic. I went ahead and bought it, and then splurged for the (not on sale) Cosmographer 3 add-on that adds capability for making spaceship deck plans, star charts, sector charts, solar systems, world maps, and more. Trying it out a little bit, it’s built kind of like a photoshop or GIMP type of raster image software, but with less graphics manipulation tools and a whole<\/em> lot more templates and built in images. It has a pretty steep learning curve, but there are some tutorial videos on YouTube to help you learn the basics.<\/p>\n\n\n\n

So I was going through the tutorials and making a basic solar system map using this<\/a> tutorial, but I was disappointed in the lack of variety and number of planet icon images. I thought to myself, “I could make some myself with a bit of work!” and immediately got side-tracked for the past several days.<\/p>\n\n\n\n

It turns out there are two basic ways you can do this: 2D or 3D based. The 2D method is something like this:<\/p>\n\n\n\n

  1. Download or create a rectangular 2D map of your planet’s surface. You can download map images for the planets in our solar system here<\/a> and here<\/a>. For example here is mars:<\/li><\/ol>\n\n\n\n
    \"\"\/<\/figure>\n\n\n\n
    1. Import the image into a 2D raster image manipulation program like Photoshop or GIMP. I use GIMP because it’s more than powerful enough for my level of skill, and because it’s free.<\/li>
    2. Use a tool (fortunately included in GIMP) to wrap the rectangular image onto a sphere shape. Basically it’s a reverse of the cylindrical projection method shown here<\/a>.<\/li><\/ol>\n\n\n\n
      \"\"\/<\/figure>\n\n\n\n
      1. Choose your options for the rotation\/angle of the sphere, lighting, and you’re done!<\/li><\/ol>\n\n\n\n

        Some sample results:<\/p>\n\n\n\n

        \"\"
        Mars viewed from South Pole<\/figcaption><\/figure><\/div>\n\n\n\n
        \"\"
        Ceres<\/figcaption><\/figure><\/div>\n\n\n\n

        What’s great about this is that you aren’t even limited to real planets, you can do this with fictional ones as well. You just need to generate or find the surface map before you transform it.<\/p>\n\n\n\n

        \"\"
        Fictional water planet<\/figcaption><\/figure><\/div>\n\n\n\n
        \"\"
        Terraformed Mars<\/figcaption><\/figure><\/div>\n\n\n\n
        \"\"
        Fictional rocky planet<\/figcaption><\/figure><\/div>\n\n\n\n

        This method could also be sped up with a bit of work, since GIMP has a full Python API. It would be possible to write a script that could upload a directory or a zip file with a bunch of map images, then convert them all to planet images and save the results.<\/p>\n\n\n\n

        However in making these I noticed there was a pretty severe limitation: there was no way to make a planet with rings like Saturn. That then brings us to the 3D method:<\/p>\n\n\n\n