Pagina's

Thursday 9 January 2020

Sequencing the states

Good afternoon. Yes you heard that right. It's even almost evening and I'm in the bus back home from work. I was just thinking about the state machine that I'm running in Holocene and there's a problem.

The problem is not unfixable by any means, but it'll make my job a lot more difficult because I am bound to create a gigantic AI class if I continue what I'm doing now.  Shop what am I doing really? Well, I'm using a state class that has actions defined for entering and exiting the state and for executing whatever the state needs for every frame. All these methods are written in the CharacterAI class.

The idea is that once something is happening, like the character finds out he's hungry, the decision class will look if there's apples to eat and if there are, trigger Moving state with an apple as target. That's all fine and that works, but...

Walking to an apple is not really the same as eating it and moving to any target does not satisfy hunger feelings, so I have to make it more complex. Once the character arrives at the apple, he'll have to interact with it.  Pick it up, maybe prepare it and consume it.  That means we need more information on what to do next. That is going to clog the system quickly.

Now here's my idea: I'm going to use the Unity animator controller and add behaviour scripts to any of the states, keeping them very modular. Moving does just the walking until it's at the destination, picking up just picks things up, eating only destroys the object and sees if that does any good to the character. All these states can me called by a simple trigger that takes a string or an int.

Back in the AI script, all I have to keep track of its a stack of triggers. The states will let the AI know they're finished and the AI will know what to do next. In the eating example, the character will run a "hunger" method and that'll populate a stack with the state for finding it there it's food nearby, plotting the road, going there, picking the food up, seeing if it needs preparing, doing that, eating the food and going back to seeing what to do next.

I'm sure this is easier said than done, but I think this is what I'm going to do.  This way I keep the code separate and unrelated and that often means less bugs and easier to manage.

Wednesday 8 January 2020

Agabouga likes apples

Good morning again. I have a little update on the development of what I started to call Holocene again. I'm focusing on the game mechanics and specifically the satisfying of needs by characters. As I might have said before, characters need food, water, sleep, warmth and probably something social.

These five are instances of a Need class. Needs have a current value, a maximum value and some priority stuff. A character will be able to find out which need needs to be fulfilled and find targets for that accordingly.

I have this system working now, but I'm going to refactor that, because I'm not very happy with it and I think we're making too many calculations which will be problematic when we're having more than a couple of characters.

Anyway, afters whatever happens, the character has a state machine component that gets fired to a new state when that gets triggered. The idea is that once the guy is hungry, he'll find a food source and sets that as target to go to. Then the state machine will trigger a state to pick up the source and then eat it. Or bring it somewhere.


What I have now is a system that presets the target for Agabouga to the apple and tells him to go there. The triggering of the move state is not implemented fully, but that will be. By the end we'll have characters being able to find out what they need and if that's available. The state machine will then get a sequence of states going. Move to the apple, pick it up, eat it and find out if we need anything else.

A lot of work left to do, but it's actual mechanics so I like it.

Sunday 5 January 2020

How to be destroyed properly

Good morning and best wishes for 2020. It's been a while but not so much that I'm getting used to typing 2020 on my computer keyboard with ease. I spent the holidays with the family and the rest of the time with my wife and a bit with some courses and experimenting to get better at gamedevving. Now I think I'm back to business.

I have been up to quite a lot in these courses and experimenting lately. The aim is mostly to get more proficient in the RTS mechanics that I need for my game. I'm going to revisit the procedural world generation later, once I have kind of a game going, so I ditched that, because I was not happy about it anyway.

I also took a look at 2D grids and A* navigation, but that gets slow very quickly once the world is getting any bigger. I think I'll just stick with the 3D Navmesh system for now. I'm not sure what other elements to keep.

Now that I started a new clean sheet project, let me tell you what I did yesterday.  You remember this tree:


This is the acacia tree. It's an object of the Tree class and it can do something. It can get destroyed. Every object of the Worldobject family had hit points and once they run out, the object gets destroyed and other stuff happens. What'll happen it's that once the acacia tree is killed, it'll instantiate a list of objects around itself. Were talking logs and branches. The idea is that a felled tree will add resources like that, while trees can also be kept alive to give a little bit of resources every now and then. 

This mechanic is now partly made. I still have to make the instantiating thing and a time system to make "every now and then" mean anything.  Time will probably be one of those main mechanics. There'll be day and night and especially seasons and hence years, because there'll be aging and growing in the game. And winters should be colder than summers, which should make a difference. 

Not sure how to implement that one though, sho we'll have to find out.  For now I'm happy to be working again.