I posted about working on the cover of Cosmic Girl a couple of days ago, and I’m coming back to the subject again, because I left off when the cover was far from finished. The cover is probably one of the most important factors in getting people interested in a book, so it is worth investing time. The amount of time I would need to invest in this cover, however, was significantly more than I had anticipated. The reason was that I ended up having to learn an entirely new section of Blender, the software I use for creating book covers.

Blender is great for book covers because you can use it to create 3D objects – like daggers, pools of blood, ray guns, lipsticks, and even spaceships and planets – entirely digitally. You therefore don’t need any props, or to book any time in a photography studio. You can also compose the objects you create into a scene, light them dramatically, and even add text, making it a one stop shop for a great looking book cover. If your cover needs a chiseled jaw and a six pack on it, you will still need a model and photographer, or airbrush artist, but Blender can do just about everything else. I can not praise Blender too highly but I must admit that it is not simple to use or quick to learn. I’ve been using it for years and, obviously from this post, I’m still learning.

I had to learn a whole new section, a component called Cycles, because I had a problem with the way the cover was rendering. Rendering is basically where the scene created using Blender is output into a jpeg file that can be uploaded to Amazon, or whoever. This video goes into a little more detail about rendering, but that’s the essence of it. The cover I’m designing features a simple pendant, which is worn by the cosmic girl in the story. My problems arose because I wanted it to look metallic, like it is made out of some alien precious metal. Unfortunately, I just couldn’t figure out a way to get it to render that way. Every time I rendered it, the pendant looked dull like plastic, not glossy like metal… so I started Googling around for a solution.

Getting a solution turned out to be tricky because I had problems understanding the advice I found. I started using Blender in the old days, when people mostly used the Blender Internal render engine, but now everyone seems to have switched over to using an alternative called Cycles for rendering. That means that pretty much all the tutorials I found for making renders look metallic tended to refer to Cycles.

I’m quite confident with the Internal engine, so I was reluctant to forget all that and learn to use Cycles instead just so I could follow the tutorials and make the pendant look metallic. But then I found out that there aren’t any software developers working on the Internal render engine anymore, it’s no longer supported, and I will therefore have to switch to Cycles one day anyway. In that light, it was as good a time as any to start learning Cycles.

I started learning with this page about nodes. Nodes are the weird and complex way Cycles is told what to do, and you can’t get Cycles to work if you don’t get to grips with them. Nodes look complex, like spaghetti bolognaise, but I quickly got the hang of the basics, and then went searching for a simple nodes setup for rendering a pendant to look metallic.

I found a very complex version of a metallic nodes setup on BlenderArtists.org, but I figured I could simplify it. The setup shown on the site uses bump maps for some tiny scratches in the surface, and other advanced stuff, but I figured I could just ignore all that. It turned out I had been a little overconfident and I got lost in the weeds for a while. Problem after problem cropped up, so I gave in. Thankfully there was a very simple reason for the problems I was having, and I eventually found it.

It emerged that I hadn’t switched Blender over from the default behavior, where it sends data to the Internal render engine, to instead send it to Cycles. You can, theoretically, also use nodes with the Internal engine and so using nodes does not automatically change Blender over to Cycles, and I hadn’t realized that. Once I found this out, I quickly switched from Internal to Cycles, with a single mouse click, and all the issues I had been encountering melted away. I also found a simpler setup for making things look metallic in a Reddit discussion. A poster named WinterholdMage posted it, and pointed out that he or she had used a:

Fresnel node plugged into the Fac socket of the mix shader. This Fresnel node has an IOR value, which tells the material how light, reflections, and refractions interact with it. Silver has an IOR of 0.18.


After some trial and error I set up the nodes like WinterholdMage told me… and… it worked. With a Fresnel node set to 0.18, as WinterholdMage suggested, my chain suddenly looked glossy, like silver, or some other precious metal. The chain looked exactly how I wanted it, and it had only taken four or five hours of work to get to that point.


After the chain, I then had to make the blue pendant more reflective and metallic, as well, which is a bit more complex than colorless silver. I found a nodes setup here to do that. I had to do more than fiddle with the nodes, however, to get it to really shine. I also had to work hard at lighting the scene, very hard.

As I learned more about lights on reflective surfaces, I set up a more ambitious lighting rig, with environment lighting, darker shadows, and brighter highlights than before, and the cover really started to pop. There will still be hours of work ahead for this cover, but as I said, the cover image is one of the most important parts of a book so it is worth investing the time. It is even worth spending hours learning how to use new features of your tried-and-trusted software suite, so you can get things as close to perfect as possible.

Cosmic Girl isn’t available yet, but you can read one of the other books I have published instead, such as Galaxy Dog.


Galaxy Dog (Dark Galaxy)

Start Reading the Dark Galaxy Trilogy

Galaxy Dog is an epic space opera. What starts as an ordinary invasion of an alien planet, brings to light an ancient archaeological site of huge importance. A young man called Knave makes a life-changing discovery there and rises from a lowly position as an infantry trooper to become a player among the powers of the galaxy. This is the story of his rise, and the story of the fierce and independent woman and the feisty robot who help him.