AI and Game Design in Unity 3D

I’d mentioned some problems getting the AI to not see through walls. They didn’t look like hard problems, but they took forever to fix. Look for an update to this post with some more depth on what had to happen, but for right now, back to scheme….

-Nate

Door Closed…

Door open!

The door and control panel are both modeled by me; I’ve been putting together a complete asset list and trying to get those out of the way early. I’m not spending much time on detail.

The control panel object you see can be linked to a door, and interacting with it using an ‘interact’ key causes the door to either open or close.

I’ve been having extreme problems with making the AI not be able to see through walls. I thought I had it down, but then AI weirdness, like suddenly standing still and inching away slowly from the player, or rocking back and forth, started showing up, and since then it’s been nothing but a headache.

The idea was to cast a line between the enemy and the player. If a collider was detected in between them, then the AI would not see the player even if they were in the AI’s theoretical field of vision. I am not completely sure what is going on, and I’ve tried many methods of this implementation, and done things like cast the ray (or line) from an empty game object above the enemy’s head so that terrain wasn’t getting in the way (he’s a stubby little guy). I’ve let this slow me down for a while, though, so now I’m trying to sort of play catch up on the non-AI design work I have to do. In my original plan, assets and gameplay specifics were supposed to come later. To some degree they still are; I won’t be able to know what the AI can do in the end until I try to make it do it. But right now I’m trying to get all the pieces I can done.

Lots of updates.

Some week and a half ago I started modeling a ‘test’ level. I had downloaded blender, but was finding it difficult to pick up. Then I remembered a program I had downloaded a long time ago called Cheetah 3D. I opened it up and found it easy to pick up; over a few hours I eventually found myself with a little maze level. Of course, I hadn’t tried to save yet (bad practice, I know, but I had been more tinkering than building), and when I did I was greeted with the message that saving is prohibited in the trial version.

I left the level open for about two days before finally plunking down the cash to buy a Cheetah license. Of course, I didn’t end up using that original level, but I now have all the tools I need to create assets and animate them. The project isn’t focused on that aspect, meaning they likely will be ugly and basic, but I think when I set out I underestimated how limited I would be without spending some of my time creating assets.

I’ve also added a sight radius in addition to a hearing radius for the enemies – if you are within their ‘cone of vision,’ they can detect you from much farther away, but only if there is nothing blocking their sight (this is an imperfect system; I’ll blog a little about it when I have more than a minute).

I’ve also been busy with a combination of work for another class, but I’ve gotten past the rough part of that.

Forthcoming in the next few days is a description of what I hope final gameplay to be like, and some research discussion.

And a link to a webplayer! I promise!

-Nate