Last update, I had just started to nail the look of the lunar landscape renders which the player will be panning around for much of the play experience. That was pretty significant milestone and was fairly easy to achieve. I’m still not 100% there, but it was good enough where I figured I should move to the next step: determining how I’d establish a consistent scale for objects and how big I should make the overall map.
The end result I’m going for is to look like blurry aerial photography taken by the Lunar Reconnaissance Orbiter, both to lend an air of authenticity to the depiction and to save me time in how much detail I need to model and texture. It also leaves the true look of things up to the imagination, which I like a lot. So the challenge is to strike a balance where small objects, like the player’s rover, are large enough where you can tell what those objects are but not large enough where you get lots of fine detail.
Determining the size of objects
I started out by doing lots of test renders in Blender with my rover model and a 1-meter cube on a test landscape and adjusting the size of those objects and the size of the final render resolution.
After spending a ton of time iterating and tweaking, waiting, rerendering, then tweaking more, I came to an answer:
1 meter = 9 pixels
On its face, this sounds incredibly low-detail – and it is! – but it hits the look and, realistically, it’s also incredibly high-resolution for an orbiting satellite like this! The Lunar Reconnaissance Orbiter, for example, can get photos with a resolution of up to 0.5 meters per pixel.
Determining the size of the world
So this naturally leads into “how big is the map we’re exploring?” And given the unit of measurement above, Some things are already clear:
> 10 meters = 90 pixels
> 1 kilometer = 9000 pixels
Because I want to be reasonably authentic, my first thought was using a real-world lunar crater or walled basin on the south polar region. But, uhh…
- Shackleton Crater: 21km diameter = 189,000px = 92x92 2048 tiles
- Shoemaker Crater: 51km diameter = 459,000px = 224x224 2048 tiles
- Schrödinger Crater: 312km diameter = 2,808,000px = 1371x1371 2048 tiles
Absolutely no way that kind of scale will work here. Both in just how incredibly vast of spaces those will lead to, but also I don’t know if I want to render and iterate on that size of canvas. So I decided to figure what what world scale does feel right, regardless of real-world parallels.
I started with making a 4x4 grid of 2048x2048 rendered tiles of test terrain, placed it in the game, and panned around to get a feel for it. This felt way too small, so I doubled it to 8x8 2048x2048 tiles. I quickly doubled this to 16x16 tiles, and this is where it felt just right: a huge terrain where it feels like landmarks can have gargantuan scale but not so large I’d either end up with lots of empty space or pressure to make unreasonable amounts of content to fill.
And this turns out to be about 4km x 4km. 16x16 tile grid of 2048x2048 renders.
Prototyping landscape features
My next challenge was prototyping the best method to fill this space with landmarks, features, and objects for people to find. This is naturally going to be an on-going process throughout development, but worth coming up with a method sooner than later.
If I did all my prototyping and iterating in Blender, re-rendering tiles as needed to put new things into the game, that iteration time would be incredibly slow. I want to basically be able to quickly sketch out stuff and then see it in-game immediately to get a real sense of things.
So I compiled all of my rendered tiles into a massive 32,768x32,768 Photoshop file. My computer hesitantly decided to allow this. Now I could draw random shapes for mountains, craters, lava tubes, etc. And with a simple script, I could split all of these back out into 2048x2048 tiles into my game’s project folder, relaunch the game, and see the results.
This works great! Iteration time this way is fast and let’s me try stuff before I commit to actually modeling and sculpting it out.
Okay, so I’ve figured out object and world scales, and it’s giving me a real sense of the size and scope of the game and that feels so, so great! But now I’m left with a huge problem:
My game’s world consists of 256 2048x2048 images all loaded at the same time.
My main computer is fine with this, but if I try to load this on my laptop, which has a pretty average amount of memory, I crash on boot. Of course I do! This is a full dump-truck of image data all at once! There’s currently zero asset/texture streaming going on, but at least I have my assets split up, so I’m all ready to tackle.
But for now, this answered a lot of questions I had with world design, so I’m going to move on to tackling more of the remaining unknowns.