In the recent C-Dogs SDL release, I introduced a new walk cycle animation using pre-rendered 3D sprites; check it out (before, after):

The content pipeline goes like this: Blender, bash/python render scripts, Imagemagick touch-up, montage spritesheet. The results are surprisingly good, given that no manual retouching was required; I can directly edit the blender file, and create updated spritesheets.

Background

Initially I was leery of this whole project. Pixel art is usually done by hand and laborious enough already; creating animations just makes the amount of work explode. The original sprites only had 4 directions (left/right can’t be mirrored due to the gun-handedness), 2 poses (unarmed and holding gun), with idle (1 frame) and walk (4 frames) animations, for a total of 4 × 2 × (4 + 1) = 40 frames. The project was to show all 8 directions with an improved walk cycle of at least 8 frames, which would make the total number of frames balloon to 8 × 2 × (8 + 1) = 144 frames. That’s a lot of work to do manually!

Not only that, but there are future plans for more improvements, like “textures”, different body types, different animations, each of which multiplies the amount of sprites.

Obviously the alternative is to model and animate the whole thing in 3D. But there are big questions around this approach. Will the animations look as good? Can rendered sprites avoid that “rendered” look?

This is what pre-rendered sprites looked like in the 90’s

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Why are open world games so fun? A lot of reasons: a huge, interesting world, lots of things to see and do. But one important mechanic that support this, and which pops up a lot when people talk about open world games, is traversal. What’s that?

In a nutshell, it’s the way the player moves around the world, getting from A to B. This sounds (and often is) mundane, which would be a problem for open world games with huge worlds, which is why these games often have interesting, advanced techniques to get around. You see this a lot on 3D open world games.

When it comes to great traversal mechanics, two games often get mentioned: Spiderman 2 and Just Cause 2. In the former, you use your web to swing around the city, and in the latter, a unique combination of paraglide and grappling hook lets you fly around quickly. Both take some skill to pick up, but the result is a fast and cool way to get around their game worlds.

Other games also get mentioned, but I’ve noticed that they are all 3D games, and the traversal mechanics described are 3D mechanics. I’ve been thinking about how traversal might work in a top-down 2D game; a lot of the things that work in 3D simply aren’t there. Like:

• Great views: open world games are fun because they have great scenery to enjoy. Many open world gamers have anecdotes of climbing up that big mountain to get a spectacular view, or seeing majestic buildings and landscapes in the distance. In a top-down 2D game this simply isn’t possible.

  

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To make better games, one can look for similar games (not only in the same genre), and see what worked and what didn’t. One game I’m making is C-Dogs SDL, an overhead 8-directional shoot-em-up. A while ago I started looking for similar games, looking for cool features I can steal, but also for where they weren’t fun, and why. Bertram25 (of Valyria Tear and OpenDungeons) encouraged me to elaborate on some of my conclusions in a blog post, so here it is !

What are Overhead 8-Directional Shoot-em-ups?

This mouthful of a sub-genre doesn’t get mentioned a lot. In a nutshell, it’s where you can move and shoot in 8 directions, from an overhead perspective. Sounds awfully specific, so people simply describe these games as top-down shooters or 2D shooters, which lumps them together with other sub-genres like twin-stick shooters (Geometry Wars), scrolling shooters (Gradius, most of the Touhou games), run-and-guns (Contra), even games like Asteroids (which have tank-controls, and includes the Strike series or even the on-foot sections of 2D GTA). Fans of those sub-genres will understand how different they are; each has different design lessons to learn.

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Recently I had to write a LAN game server/client for C-Dogs SDL. I was surprised at how little information was available, so I thought I might document my solution here.

The Problem: Which IP to connect to?

Most people who have made, or attempted to make, network-multiplayer games will know that there are two ways to get two game instances to connect to each other:

1. Directly, by entering the IP address of the other game instance, or
2. Using an online “server list”, which is basically a list of IP addresses constantly updated

Most “game server browsers” actually download lists from several known locations, a fancy way of doing no. 2. But no. 2 boils down to picking an IP from a list, which the game then uses to connect to directly anyway - no. 1. The point is: to connect two games, you need the IP address.

_{In ages past there were dial-up modems where you could connect using phone numbers, or IPX which is similar to IP but has different addresses. The protocols have changed but the problem is the same.}

But how do games see each other on a LAN? Somehow many LAN-enabled games can scan and find servers running on a LAN, and avoid having to enter IP addresses manually. They also do this without having to access a remote server list.

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The latest release of C-Dogs SDL is ostensibly about the addition of deathmatch mode, and although it was the original goal and most notable feature, development took twice as long as previous releases, and largely for one reason: ammo. Before this, C-Dogs didn’t have ammo, or in other words, C-Dogs had infinite ammo. How could ammo be that hard to implement; surely it’s just an extra counter? I though the same, but I soon realised this:

Ammo is a resource.

And that leads to a heap of things related to resource management. The player must now contend with many more decisions:

• Which gun should I use? (some guns have rarer ammo)
• How should I engage enemies? (close-up saves ammo but is riskier; farther is safer but wastes ammo)
• Should I run away altogether and save ammo?
• Should I explore, and gamble on finding more ammo or having to use it up on new enemies?

And as a designer, you now have to contend with:

• Making sure the player is not too starved, or over-supplied
• Resetting the player with the right amount of ammo at key points
• Being careful not to railroad the player into a few play styles due to ammo supply

Of course there are great rewards for implementing ammo. It adds a layer of depth via the decision-making. It gives players an incentive to use different guns, as overusing their favourites will make them run out of ammo. But it’s also an entire game mechanic, and for one that’s so old and common, it’s surprisingly hard to get right.

Games like these are too easy with lots of ammo, too hard without. Ammo placement can make or break a map.

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