Cockroaches in Buildings!

I can't resist adding another "animal" type to 3DWorld's procedural buildings. It was a lot of fun (and also a lot of work) to add rats, spiders, snakes, and flies. Now that I have all of the framework in place for animal drawing, animation, physics, collision detection, behavior, etc., it should be easy to add more animal or insect types. Cockroaches are somewhat of a cross between rats and flies. (Well, assuming you only have the four animals/insects mentioned above to work with.) They walk on the floor and run away when scared like rats do. Their placement and drawing code is closest to that used for flies. I was able to reuse enough code from existing animals that it took me less than a week to add cockroaches, compared to several weeks for rats and spiders.

Cockroaches have some unique behavior characteristics. They only spawn in dark rooms away from the player, building AI people, and zombies. They have a random walk => stop => turn cycle similar to rats with some degree of random speed variation. When they're startled by a light, a sound, the player, or another person, they immediately run toward the closest wall in a direction away from whatever scared them. When reaching a wall or other object flagged as a hiding spot, cockroaches disappear inside and are respawned somewhere else in the building. Their new location will be somewhere dark and out of view of the player. If they instead hit an object they can't hide under, they turn away from the object, suspend their fear state for a few seconds, and walk in a random path.

So far I haven't assigned any gameplay purpose for cockroaches. They don't affect the player or zombies. The player can't pick them up, but they can be squished by dropping objects such as books on them the same way as spiders. However, it's quite challenging to squish cockroaches due to their fast speed, small size, and ability to hide under objects. Maybe I should track kill counts for both spiders and cockroaches. As a placeholder for this, I add $10 damage for each squished bug for building cleaning costs. (For reference, cleaning the blood stains from a player death is $100.)

I originally drew cockroaches as simple stretched brown hemispheres: long and flat. I didn't bother to add legs because it was difficult to get close enough to see them. Later, I decided they looked too plain, so I found a 3D model online that looks much better. So far I haven't felt the need to animate their legs because they're so small and move so quickly. The 3D model rendering code is almost identical to that used for rats, in particular because they're both always oriented in the XY plane on the ground.

Here's a video showing a building with 1,000 cockroaches. They scatter when I turn on the light and approach them. Note that these are drawn at an incorrect height and their legs are under the surface of the floor. I've fixed that in the other screenshot and video below.

And here's a screenshot showing the 3D cockroach model I used. Yeah, it's pretty small and hard to see.

Cockroach on the floor, drawn with a 3D model.

Here is a video showing me attempting to drop books on cockroaches to squish them. It's challenging and took me a number of tries to get the first one. They have yellow blood!

Do you have a suggestion for what animal or insect I should add next? If so, please leave me a comment.