The first big update for evolution simulation game The Sapling will release September 10th, and will extend the indie sim with major new functionality.

• Pollination & flowers, allowing the plants you designed to mix their genes. One way to spread pollen is by attracting animals with colorful flowers.
  
• A new sandbox level, completely redone and 100x larger! Besides random mutations and timejumps, it now also allows you to change the overall temperature and see what that means for evolution.
  
• A new scenario, teaching you how to set up an ecosystem with flowers.
  
• Extensions to the procedural music system. It now adds rhythm in if you speed up time, making it even more responsive to your actions.
  
• Bioluminescence. We all know that bioluminescence is cool (https://tvtropes.org/pmwiki/pmwiki.php/Main/BioluminescenceIsCool), so you can now add it to your plants and animals as well, to attract other creatures.

Solo dev Wessel Stoop made good use of the current quarantine situation and spent 3 months to completely rewrite and optimize the underlying engine, making scenarios that are 100 times larger a possibility. It took a lot of blood, sweat and tears (okay, only sweat), and resisting the urge to not implement pandemic functionality instead, but when Stoop found himself accidentally playing and enjoying the game again instead of bugfixing, he knew something was right. The larger terrain is what made the rest of the features possible; mixing genes does not really make sense in ecosystems so small that they are fighting for space to grow.

More details on the flower update will be revealed gradually over the coming weeks on https://thesaplinggame.com/flower:

• August 17: more details on the pollination & flower mechanics
  
• August 20: more details on the new sandbox
  
• August 24: more details on how bioluminescence works
  
• August 27: more details on the UI overhaul that is also part of this update
  
• September 3-10: Twitch livestream where viewers can vote for the temperature to go up or down... will the ecosystem be able to adapt in time?

Useful links (that is, useful to me, but you might also like them):

• Twitter: https://twitter.com/thesaplinggame
  
• Press kit: https://thesaplinggame.com/press/sheet.html
  
• Subscribe to the newsletter: https://thesaplinggame.com/newsletter
  
• Website: https://thesaplinggame.com/
  
• First look video: https://www.youtube.com/watch?v=-tFe4_-7cFA

Writing game code and creating game graphics are two fundamentally different beasts, and what is fun about them is very different. Programming has the clear advantage when I'm inspired by another game and want to see if I can replicate a particular idea. For example, if I encounter a game mechanic that I like, I can do a quick internet search and the result is most likely a tutorial on how to build this kind of technology. If I like the graphics in a game, on the other hand, there's not much I can do other than endlessly combining tricks I already know and hope this by chance achieves the graphical style I was trying to reproduce.

In this article I'd like to show you it doesn't have to be this way; I'll set a good example and explain in detail how to achieve the visual style of The Sapling. I will do this step by step, and (inspired by the large number of visitors for my previous interactive devlog) interactively with sliders, so you can compare the impact of the effect. At the end there's an interactive scene so you can turn on and off everything to your heart's desire.


The Catmull-Clark subdivision algorithm is like a machine where you can put in a simple 3D object, and a smooth more detailed object comes out. Fun fact: the Catmull in the name is actually Edwin Catmull, former president of Pixar and Walt Disney Animation Studios. Implementing it was my first experiment in Unity, and with it I showed myself that I was able to do 3D game programming. The algorithm allows the game to work with basic shapes for the models of plants and animals under the hood, while they appear more realistic to the player.



Depth of field is a fancy term for making the background blurry. I really like depth of field in film and photography as it guides what the viewer focuses on in a very natural way. Unfortunately it often does not work well in gaming contexts: in most situations, the player should be able to focus wherever s/he wants. On top of this, depth of field makes objects feel relatively small; depth of field on anything larger than a human makes it look like some kind of miniature version - although recent city building sims use this to their advantage to create a 'toy city' kind of feel. In The Sapling, depth of field is used when the player clicks a plant or animal to focus on it. Look at the background in the image below to see the effect.



A vignette can be many things, but I think its default meaning is to make the corners of an image darker. Unlike depth of field, I rarely like vignettes in film and photography but I almost always do in games. I guess it's because a really simple trick that most players won't actively notice, while it does give the game a more artistic look.



A comment a lot of early playtesters gave was that the island looked empty and boring when you start. While I still haven't come up with a way to really fix this, I think that moving water makes the whole thing feel a little more alive. If you're into the technical terms, it's achieved by saving the effect of displacement modifier in Blender as shapekeys. You can turn the moving water on and off in the interactive scene below.

I came up with this idea quite late in the development of the game (before that, the sky in The Sapling was simply always blue), but the effect on the overal atmosphere was enormous. Interestingly, this can be achieved in the Unity game engine by using 3 pixel textures like these ones (enlarged versions):



This is the effect for a single point in the day night cycle with a slider for comparison. In the interactive scene below, you can actually move through the whole cycle.



Of course, beautiful skies only work when it matches the colors of the rest of the world. This is mostly achieved by simply changing the colors of the lights of the game along with the sky. Like with the skyboxes, you can see the effect for one point in the day night cycle here, and for the whole cycle in the interactive scene below the article.



Color correction has the same goal as the colored lights (color the world to fit with the sky), but with a different approach. Whereas colored lights have much more effect, color corrections create a more unified and pretty look. This made them great together.






Want more like this? I write articles like this roughly once per month; you can subscribe for email reminders here! If you want more fine-grained info on my game development work, there also is a Twitter account.

The arrow button above plays a short excerpt of what the music in The Sapling sounds like. I hesitated a long time before I settled on this musical style. Normally, I prefer memorable, hummable melodies over soundscapes, but for The Sapling I couldn't figure how this would work. This was mainly for two reasons: firstly, every melody I came up with didn't really seem to match with the rest of game's style. Many other simulation games feature either jazzy (like SimCity) or bright and jumpy (Equilinox, Planet Coaster) soundtracks, but both styles somehow seemed to clash with a more serious game about nature. Secondly, I was afraid that I simply would not be able to come up with enough material, meaning that the same melodies would be repeating over and over.

The solution came from an unexpected direction: during experimentation with ambient background music to get into a more productive programming mood (which by the way didn't work for me), I noticed that ambient music videos on Youtube often used a slideshow of pretty nature photos as 'background visuals'. Would it also work the other way around? If nature makes a good background visual for ambient music, is ambient music good background music for nature visuals?

Accepting this - and thus giving up hummable melodies in favor of long slow 'ambient' notes to evoke a relaxed feeling in the listener - was a slow process, but ultimately lead to a second discovery: a lot of ambient music rarely changes chords. Instead, all notes throughout the whole song are from the same musical scale. This is convenient, because a general (and oversimplified) rule of thumb is that two pieces of music that use notes from the same musical scale are likely to sound good together. Creating an ambient sounding soundtrack could simply be a matter of creating a large pool of musical fragments that only use notes from the same scale, and mixing them at random. How well this works is exemplified by the project In B Flat (which, as the name suggests, uses B Flat as this one scale).

This idea solved my two problems in one go: (1) the genre of ambient music fit the game's feel and (2) I could endlessly combine small musical fragments, giving you a fresh sounding soundtrack every time. The result is available for you to play with below. Feel free to click some play buttons at random, and decide for yourself if you think they sound good together.



My own conclusion, after playing with this for some time, was that although everything indeed sounded good together, some combinations were better for videogame background music than others. In the end, I identified five categories of fragments:

• The background, with long, sleepy tones. These are what gives the music its ambient feel. Strings are the most typical example.
  
• The foreground, played by a single instrument with short notes, grabbing the listener's attention. I most often use the piano or the celesta for this.
  
• The color, which is somewhere in between: they are played by a single instrument, but use long notes. These give a bit of flavour to a background that would otherwise always sound similar. This can for example be a clarinet or a trombone.
  
• The bass, often played by double bases or base clarinets.
  
• Victory sounds, that temporarily grab the player's attention and give them a satisfactory feeling.

Furthermore, I discovered that using strings in unisono with octave intervals (playing the low and high versions of the same note at the same time) worked quite well to give the mix a more epic feel. In the end, I used this together with the bass as the player is looking at his/her creations from a distance: as the player zooms out, the bass and unisono fade in.

The button below categorizes the musical fragments above, and for the fragments in the background category adds an option to 'switch on' the epic version. If you make sure that for every category only one fragment is playing, you get something that could also be played in game.



One final question you might have is whether these musical fragments are completely random sequences of notes chosen by chance from a static scale. The answer is 'of course not': to satisfy my own desire for hummable melodies I actually did write a main theme for the game, and to give the game some musical coherence I echo parts of this theme in various fragments. This button below plays the main theme as you hear it in the main menu. Can you identify which of the musical fragments contain hints of this theme?



And that's all there is to it! By the way, if you want to do more with these pieces of music, you can! Both the individual fragments and the layers of the main theme are availale to be used in your own projects, as is the sheet music for the main theme. See this devlog for more info on that.

Want more like this? I write articles like this roughly once per month; you can subscribe for email reminders here! If you want more fine-grained info on my game development work, there also is a Twitter account.

As of today, The Sapling is available as an Early Access title on Steam (and soon on itch.io, GameJolt and Kartridge). Let's celebrate with a microtrailer:



It's quite a weird feeling to think that this game, which has been my side project for so many years, is now available to everybody. The game was of course already playtested by dozens of players (which turned out to be an absolute must, as it was way too complex and confusing in its early iterations), but the fact that there's now a Steam page where you can click 'Buy', videos that are watched by thousands of people, and comments everywhere talking about 'potential' - it's a feeling that's hard to describe. As a side advantage, these videos also show me some major mistakes that still need fixing; I'm creating a new build with some fixes as I write this.

The nicest responses have come, perhaps unsurprisingly, from Spore fans. For example, my absolute favorite video of the game is this one by KinglyValence. KinglyValence is a speedrunner that currently holds the world record for all individual Spore stages but the first, in all difficulties. He spent some time analyzing The Sapling and managed to complete all four scenarios in a whopping 10 minutes and 16 seconds!

Speaking of Spore, most questions I received over the last few weeks were related to Spore in some way or the other. So what is this relation between The Sapling and Spore anyway? The Sapling was originally conceived during a bicycle ride to school in 2002; at the time I was so excited about it that I was planning to write to dozens of game developers to 'give away my idea for free' (at the time not realizing that having an idea is not that special in the game industry, realizing one is). Little did I know that at that time Will Wright, father of simulation games and an absolute hero to me, was already working on it. You can imagine my excitement when he revealed Spore at GDC in 2005; it became an absolute obsession of mine. Checking several Spore related news sites was the first I did when I opened up a web browser these days.

Since its release in 2008, though, I have only played through the game twice. Turns out what I liked so much about Wright's earlier work is that they were sim games; a detailed simulation of some real life phenomenon to toy around with. Spore was a collection of little games in multiple genres (2D arcade, action, strategy) that together formed a narrative. While a beautiful idea, it was not the game I had dreamed up in 2002. In the mean time, I had started to make games in my free time (starting with GameMaker, then with Pygame) and I started to feel more and more ready to build a small game around the idea myself in Unity 3D. It must have been around 2015 that I completed an implementation of the algorithm Catmull-Clark for Unity, essential for the editors in the game, that convinced me I could do it. I wish I'd had known back then it would all result in me writing this release blog post today.

As the release date of The Sapling is coming closer, it's time to give you some more insight in the game. Therefore, I am releasing six models created by playtesters of The Sapling, using the plant and animal builders. They can be looked at from all sides, or they can be downloaded to incorporate them in your own 3D creations.

One thing I noticed from the responses to the 'First look' video is that it was not clear to everybody how deep the simulation really is. Therefore, I have used Sketchfab's annotation functionality to highlight various bodyparts of the organisms displayed, and explain a bit how they impact the simulation.

The models can be viewed here:

• Plant 1
  
• Plant 2
  
• Plant 3
  
• Animal 1
  
• Animal 2
  
• Animal 3

The Sapling was built from the ground up with community interaction in mind. This interaction goes both ways: players can take stuff generated by or for the game, and use it in their own creations, or they can add their own creations to the game.

This article functions as an in-depth guide on how to do this, to be used as reference. It's a living document that will be updated continuously. If you find any things that are unclear or just incorrect, or have more ideas you want to share with other creators, drop me a line at thesaplinggame@gmail.com .

Overview of the information on that page:

• Repurposing material from the game
  
  • Music
    
  • Exporting lifeforms and animations generated by the game
    
  • Using gameplay statistics from the API
• Extending the game
  
  • Scenarios
    
  • Body parts
    
  • How to create asset bundles

Today, the main theme of The Sapling was officially released on SoundCloud. It's an attempt to mix an ambient music like sound with a recognizable melody - and if you listen carefully, you will indeed recognize this same melody throughout the game. Have a listen on SoundCloud: https://soundcloud.com/wesselstoop/the-sapling-main-theme .

Because I would very much like to encourage covers and remixes of this material, I also release sheet music and the separate layers of music used in the main theme.

• Separate layers used in the main theme
  
• Sheet music for the main theme.

To further encourage other people playing with the material, I will hand out free Steam keys for every serious cover and remix attempt . E-mail me at thesaplinggame@gmail.com .