Site move (again)

So, I moved my existing Joomla website over to wordpress. Which hopefully makes things easier to maintain for me in the future. Will be posting new content RSN!

Clara & Pong

In 2016, I started my own web comic revolving around a girl named Clara and her best friend Pong, a red panda. These were just short weekly strips, which I initially inked by hand, scanned in, and colored digitally. Here’s one of the first episodes, where Pong receives his name:

After about a year, it was time to start a bigger story about my two heroes! I didn’t realize how big it would become, though: The story has now reached 70 pages, with one published page per week. The final book will be around 100 pages, hopefully finished by the end of 2018. It’s only German so far, but I hope to do a translation once I’m done with the first pass. Here are a few sample pages:

This continues to be a huge and rewarding personal adventure. Just as in software development: When you don’t even know what you don’t know about what it takes to finish a project, that’s where the fun is and where the best learning happens.

Urban sketching

My main day-to-day sketching activity, in a watercolor sketchbook. I mainly use a small watercolor kit, a fountain pen, and/or a ballpen.

For a 100-day project, I varied my urban sketching a bit: The task was to add some fictional element to whatever I found in the city. These are a few of my favorite sketches. They have all been inspired by places in Munich – can you find out which?

Characters and portraits

These are a few character studies, in digital, copic markers, and inkbrush:

Being interested in characters, I do portrait practice as often as I manage, in various degrees of stylization.

If you want to see more of these, check out my Sktchy account @koljakaehler.


For the Inktober challenge, the task is to produce one ink drawing on every day of October. I usually follow the official prompts, and set myself a subject matter for the month. In 2018, I created a small sci-fi story setting for each prompt – here are my favorites:

In 2017, I wanted to draw animals and be a little more experimental with various types of ink. These were all done on toned kraft paper, which doesn’t take copious amounts of ink so well – sorry for the wrinkles!

Landscape sketching

Every once in a while, I’ll try my luck with landscape sketches in gouache. I like gouache because it allows painting opaquely, and together with my small watercolor kit, it’s still convenient enough to carry around.

Pocket Observatory at Make Munich

Pocket Observatory at Make Munich! Slipped in at the very last minute, and probably had the tiniest desk in the hall. But the response was great, I am still totally overwhelmed by the positive response and all the enthusiasm. A huge THANK YOU to everyone who came over to check out the app on Gear VR! Nice people, great conversations, useful feedback, and even more ideas for future development. After two days working the desk non-stop (together with my wonderful GF) I feel a little spent but very inspired 🙂

Pocket Observatory released for Gear VR

On 3/16, Pocket Observatory has been released to the Oculus App Store for Gear VR! It has taken a lot longer than expected, but in the end, the additional iterations and feedback have improved the product tremendously. Of course, this is only version 1 – there are tons of additions on my list already, and I am open to suggestions 🙂

Here’s a link to the product page in the store.

Venturing into social VR with Pocket Observatory!

The past few weeks I’ve been working away on a really exciting feature for the upcoming Gear VR version of Pocket Observatory: You will be able to invite a friend (on the Oculus platform) and start a voice chat beneath the stars! GPS coordinates are exchanged between the app instances, so players can visit each other’s GPS locations. This is currently under review, and will hopefully be up in a few weeks in the Oculus Store.

To my knowledge, this is the very first social VR astronomy app ever! I’ve been thinking about this for quite a while during initial development, but didn’t realize how easy it would be to integrate using the Oculus platform SDK. Mind you, setting up peer-to-peer networking can still be nerve-wrecking, given the unreliable nature of network communication, but still… managed to pull this off in just a few weeks. Happy!

Check out the updated page at for the details. Here’s a screenshot of the chat UI: (thinking about avatars and a shared space experience, too, but that’s for later.)

Educational VR molecules

Now that I’ve gained some experience with Virtual Reality and my astronomy app, I’m thinking educational software for VR could be a worthwhile field for future projects. So I’ve started tossing ideas about, one of which involves playing with molecules in a VR environment.

Aspirin molecule