Lurker!

It's been a couple weeks since my last substantial blog post, so I'd like to share what I've been working on during the last week: a new monster I've tentatively dubbed the Lurker, but I plan on giving it a more original name in the future. Note that enemy development isn't normally going to take a week per enemy--I was busy with some personal things. On top of that, this enemy is more complex than my first enemy, the Blob, and required a few engine infrastructure changes to implement. I'll go over those in detail, too!

I wanted to add a new enemy which will appear in the first area of the game, Gloomstone Cave. The idea is that you'll be facing this enemy in a few spots, but initially you won't have a permanent weapon to defeat it with. So, you must come up with more creative ways to pass the first few of them, whether it be total avoidance or using an alternate means of damaging them. Later on, when you have a weapon, they won't be quite as menacing, but the initial encounters should definitely impart fear into the player.

The Lurker waits underground in a certain spot and emerges if the player gets too close, bursting out of a hole in the ground, blowing debris everywhere. Here is my temp MSPaint art that I used as a placeholder for the enemy sprites so I could start working on the programming immediately:

This is why I'm working with an artist. Body/front/side/back views.

I took a series of videos as I developed the Lurker, so you can see how it's evolved. At the end, I'll share the source code so you can see what the latest programming model against my engine looks like!

Part 1: The Lurker Emerges
This video shows the lurker enemy popping out and swaying in a sinusoidal motion. It doesn't do anything interactive yet.

Part 2: Moving around, basic attack

The lurker moves around to avoid the player, and randomly attacks him if he gets close. Then it gets stuck in the ground, and that's it.

Part 3: Real art, attacking, taking damage

At this point, Allison, the artist, started working on the graphics. The initial design was a cool and creepy monster with a sideways mouth, with plans to animate it chomping the player. You can see the down-facing graphic in this video. Also, I made it so you can hit the head with weapons, and a very basic 'death' animation for the enemy.

Part 4: Better art, cool hit colors, refined movement. Better death animation.

I make various (subtle) changes to the movement behavior of the enemy. Allisonchanged the head design of the monster to a more traditional shape, drew the other angles of the head, and animated the arms on the body segments. So now it's like a creepy dragon caterpillar. I added a more satisfying death explosion animation.

Part 5: Bigger, badder, more explosive
We increased the size of monster. A way better death animation with a bunch of explosions for the head, and a prettier hue shift during hits.

Part 6: Snapping animations, cave shards. Job's done!

I put the monster in its natural habitat, the cave. Allison added animation frames for the head so I can control its mouth--when it pulls back, it opens its mouth, and clamps shut as it attacks. Also, it opens its mouth in pain when I hit it. Allison also made better looking shards that explode out of the ground when the lurker emerges, and I added a rumbling sound (and a temporary hit sound) for the emerging stage.  Check out the final product!

Source Code

Disclaimer: I don't typically comment code except for explanations of 'why' (not 'how'--see this article) but I've marked this example up extensively for clarity. I also don't typically have classes that are anywhere near this large; my average class size is quite small, generally following the Single Responsibility Principle. I would probably consider breaking each enemy state into its own class. But, for the purposes of this example, I'm keeping this all in one class (for now).

Anyway, the full source code can be found on this pastebin, right here.

That's all for now. Next I'm going to be fleshing out a bit more of the first cave area.