Am I being too ambitious?

Hi all,

Played with the MMF2 demo a few weeks ago and now I'm the proud owner of the product. I feel like I've joined a club.

There are an incredible amount of tutorials and other bits of advice out there, whether its for creating an entire game or explaining how to create one element. I've made a couple of prototypes on my own, both of which were extremely basic. Now I've done that, I want to focus my time on a project that will help me to learn new MMF2 skills/extensions on the way.

So... fast forward a bit... there are several mechanics that I would like in my game that I can't really create at the moment. I was wondering if you (the community) could help me out...?

1. Line of sight - existing tutorials seem either too unrealistic or just don't explain well enough (specifically naming the Move Safely 2 particle effect thing)
2. Patrolling/Path movement - this is pretty straight forward, but when it's coupled with line of sight, follow/search and shooting mechanics then it gets a little more complicated
3. Follow/search - once the enemy sees the player via line of sight they should follow the player, unless they move out of view again - pause and return to patrol
4. Shooting - as explained, while Patrolling/Aiming/Following I would like the enemy to shoot at the player
5. Special Ability - the player will have the ability to 'phase' through walls, thus evading patrols and evading the enemy actively following him/her

I think my question really is, well, multiple questions. How best to do each of these mechanics?

The things I can foresee being issues are:

• Not letting the enemy see the player when an obstacle is in the way, even when actively following the player.
• Not letting the player 'phase' so that they get stuck, leave the play area, or similar.

So, where do I begin?

When it comes to visuals/elements, all I need is an enemy, a player, and some walls to make a room. Then I can test all the mechanics. It's programming that seems complicated and a bit too much right now.

Please shed some light!!!

Cheers all.

Welcome to the family! THere are ways to customize and optimize each of those things for your needs...it really depends on the game play etc... like I've seen really un-optimized line of sight examples that constantly shoot invisible sprites in ALL direction to see if any hit the player... this is insane.. for most games, you only need to shoot directly at the player and see if that hits the player or stops at a wall etc first.

The phase thing is a cool idea and will just require some clever game design and code to make work nicely...if need be, you can place invidible sprites which signifiy which wall etc can be phased through to make game-breaking phazes impossible manually per level...otherwise come complicated eventing will definately have to happen.

good luck. I hope the rest of the comunity can help in greater detail.

cheers

I don't think those mechanics are too ambitious. Go for it! If you need any help on specific parts of it, let us know. Also, welcome to the forums!

Hi @LemonyWeasel.

If you check out: http://www.castles-of-britain.com/mm...lessitemap.htm you'll find a lot of stuff you're looking for. Just download and dissect and learn and enjoy.

Well there is no "best way" to do any of it. My advice would be to tackle each thing individually and then combine them together.

Okay, so a few things. First of all, check out Marv's site as foyzul2002 suggested. He posted the older version of Marv's site however. This one might be different, but idk. Check it out just in case.

Link


Line of sight - The best way to test line of sight is to stretch a small active object from object A to object B. This involves stretching the object and changing it's angle. Search the forums for 'line of sight' and you'll probably find a good example. Using the surface object to achieve this might be the best solution.
Patrolling/Path movement - Give your enemies the path movement type. When the line of sight (LoS) line isn't overlapping an obstacle it means that the enemy can see your character. At this point in time have the enemy look in the direction of the player and set his speed to 0. Once the LoS line overlaps an object again have the enemy resume his path movement by setting his speed back to what it is normally. This will only make enemies shoot at you however; it won't make the enemies run after you. The problem with them chasing you is that it starts to get into AI related stuff which is pretty hard to accomplish.
Shooting - This is pretty easy. While the enemy is looking at your player simply have an event that makes the enemy shoot in the direction of the player. Make sure you have your Action point set to the right location so that enemy actually fires the bullet out of the gun he/she is holding.
Phasing - You're right to be concerned with getting stuck in walls or leaving the play area. Those will be issues assuming your character can only phase through walls for a short amount of time. I wouldn't worry about this until you get the other stuff down first.

This can certainly be done though. I've done all of the things you mentioned (including the chasing, resuming patrol, and phasing through walls stuff) even though they weren't necessarily all in the same game. Good luck to you and welcome to the forums!

There is a Line of Sight extension, but it only works with tile-based maps.

It is do-able, but it's also very ambitious for a first project.
You'd probably do well to get a good grounding in the basics first, which you can do with even a really simple project.

eg. Create a Pong clone. Now give the ball a custom 360 degree movement and make it bounce realistically. Now make the AI opponent anticipate where the ball is going (instead of just following it). Now make it so you can have multiple balls (multiple instances of the same "ball" object) in play at the same time.
It might sound easy, but it'll teach you about custom movements, fastloops, object scope, etc - all of which are essential for almost any game.

I can easily teach you most of this thorugh a simple example .mfa
...Just a bit later though...

Quote:

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Originally Posted by Konidias

Well there is no "best way" to do any of it. My advice would be to tackle each thing individually and then combine them together.

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I second that!

Agreed too. Make many small games first. Problem with starting big is that you'll improve so much so fast that you'll want and need to rewrite your game over and over again to keep it on par with your skills. There is no way you can start out with something you'll be able to build your whole game upon (maybe unless you're a skilled programmer already). This is why small games is the best way to start; each game will be better and better until you're ready for the big one.

Also, know that starting too big is the single most common mistakes new game developers do. I did exactly that and almost game up game dev because I could never finish anything. It took off the moment I decided to try something small and now game development is my only income. One week per game max (and put them up on the web), that's a great way to start.

Thanks for all the replies...

@BrashMonkey - I guess the single line of sight shot directly at the player will need some trigonometry to determine a field of view, eg, enemy can see 140 degrees in front of him. Is this right?

I had the same idea for the phasing - the maps won't be huge so invisible sprites will be the way forward I think.

@happygreenfrog - thanks for the encouragement! I reckon I'll be asking a lot of questions over the next few months... lol

@foyzul2002 - thanks for the link. I've seen that site before but felt overwhelmed by the amount of examples. I guess I just pick and choose the ones I want.

@Konidias - that is definitely the plan. Although I think I tried to tackle the line of sight mechanic first and found it difficult, which kind of put me off/made me write the original post. It may well make sense to start with the easiest and get more complex as I move forward. I just realised how obvious this is...

@gkinfinity - thanks for the advice. Your comments about the patrolling were helpful - I can see myself adopting the low-level AI of keeping them on a strict path or static in the initial version but maybe as I learn I can add the search/follow mechanics.

@Eliyahu - the game won't be tile-based but this may be helpful in future projects. Thanks anyway!

@MuddyMole - that really does make sense. I've done a fair few tutorials but when you mentioned custom movements, fastloops, and object scope, I realised I had no idea what these were... I shall look into this. cheers

@King_Cool - this would be really helpful, but maybe I should try and do each mechanic myself and then post it up here for you to take a look at / critique, etc? I'll probably PM you if I get to that point.

@jbrown2177 - will do!

@Nifflas - this is a problem I always have. Big ideas and I hardly ever finish anything. To be honest I would be happy if I finish just one level of this game. A really small level. It really is just about testing the mechanics.

When you talk about small, are you talking smaller than this-

One level, a top-down view of an office. Probably around 6 enemies, each with their path movement, etc. Aim is for player to retrieve keycard and make their way to the lift at the other end of the office. The whole view will probably be one frame of 600x480 or something so I can upload it to the web.

Also, could you let me know a bit more about what you do re: game dev, how you get your income, etc?

Quote:

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Originally Posted by LemonyWeasel

1. Line of sight - existing tutorials seem either too unrealistic or just don't explain well enough (specifically naming the Move Safely 2 particle effect thing)
2. Patrolling/Path movement - this is pretty straight forward, but when it's coupled with line of sight, follow/search and shooting mechanics then it gets a little more complicated
3. Follow/search - once the enemy sees the player via line of sight they should follow the player, unless they move out of view again - pause and return to patrol
4. Shooting - as explained, while Patrolling/Aiming/Following I would like the enemy to shoot at the player
5. Special Ability - the player will have the ability to 'phase' through walls, thus evading patrols and evading the enemy actively following him/her

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LOS
- Your Agents need to have a 'forward' Angle_ ( AltValue ), wich is the Angle the Agent is facing, and optionally, moving.

- Yor Agents who are going to have LOS need to have 2 Alterable Values wich define their LOS:
ViewRadius_ ( their max view distance )
ViewAngle_ ( how 'wide' their LOS will be )
This will create an invissible 'Pizza Slice' type LOS

- Your Agents need to allways know 2 pieces of information ( stored in ALtValues ) to be able to detect the Player in their LOS:
DistToPlayer_ ( the distance between the Agent and the Player )
AngleDifferenceToPlayer_ ( the absolute difference between 'Agents Angle_' and 'Angle from Agent to Player' )

- If your Agents LOS need to account for Obstacles ( wich they can not see through ), each Agent needs to draw a Line stretching from the Agent to the Player.
This way if the Agents Line is overlapping an Obstacle you will be able to conclude that the Agent cant see the Player regardless.

LINE ( THE OBSTACLE DETECTION LINE )
- Create a new Object called Line and make it 1x2 in dimencions ( fill it with any color you like ).
- Make sure ( through coding ) there are allways the same number of Lines as there are Agents.

- Pair up the Lines and the Agents like this:

Allways
-> Line set position to Agent position
-> Line set Xscale to 'Distance between Line and Player'
- Line set Angle to 'Angle between Line and Player'
( This makes sure eah Agent gets a Line wich is drawn form the Agents position to the Players position )

Allways
-> Set line AltValue IsOverlapping_ to 0

If line is Overlapping Obstacle
-> Set line AltValue IsOverlapping_ to 1

Allways
-> Agent set position to Line position
-> Agent set AltValue LineIsOverlapping_ to Line IsOverlaping_
( This makes it so that each Agent knows if their Line is Overlapping an Obastacle )

In short this makes sure all Agents have a line wich is drawn from the Agent to the Player, and makes Agents know if their Line is overlapping an Obsatcle.

PATROLLING
This is not going to be easy, but there are extencions like the path movement/ advanced path movement extencion wich can help you.

FOLLOW/ SEARCH
- Once you get the LOS working, you need to ( for example ) set Agents Flag0 ON when its seeing the Player, and Flag0 OFF when its not seeing the Player.
- If your Agents LOS needs to accont for Obstacles ( wich they can not see throught ), turn Flag0 OFF if their Line is overlaping an Obstacle ( LineIsOverlaping_ = 1 ) regardless.
- Once this is done, you can freely programm different behaviours to your Agents depending if Flag0 is ON or OFF ( seeing the Player or not seeing the Player ).

SHOOTING
- When the Agents Flag0 is ON ( Agent is seeing the Player ), your can programm the Agent to shoot in forward Angle_ or directly towards the Player.

SPACIAL ABILITY
- When Players ability is active turn Players Flag0 ON, if its not turn Flag0 OFF.
- When this is done you can make Obstacle/ Wall collisions only work when Flag0 is OFF ( ability is n ot active ).

...
As others have said before me, you really should create 5 seperate application for each of the features and tackle 1 feature at a time.
My advice is to do LOS before Follow/ Search and Shooting.
And maybe Patrolling before LOS ( but Patrolling can be hard to do ).

...
The top 3 most difficoult features to do will be:
#1 Patrolling
#2 LOS
#3 Follow/ Search

The 'Advanced Direction Object' will be of immence help to you when doing most of your features.

Hope this helps :)

Attachment 7199

@King_Cool - i'm really struggling to follow your directions. I checked out your other post describing this in more details but I just get lost.

When running the app above the flag appears to be on constantly.

There's a couple of things - how can I tell MMF in the AltValues that I am talking about pixels and angles/degrees... how can it tell?

Can I get a visual of the pizza slice/field of view to show the direction of the Enemy object?

My previouse post was just meant as some sort of general guideline as to what you need to do to achieve the features you describled ( i should have mentioned that in the post ), not a detailed technical walkthrough of how to do it.

...
Your questions:
There's a couple of things - how can I tell MMF in the AltValues that I am talking about pixels and angles/degrees... how can it tell?
You cant and there is no reason MMF2 needs to know what the AltValues are meant to indicate. Its all about how you treat the AlterableValues and what you use it for.
Example:
Angle_ = random( 360 ) ...degrees...

Allways
- Set Object X position to Object X position + cos( Angle_ ) * Speed_
- Set Object Y position to Object Y position - Sin( Angle_ ) * Speed_

This moves the Object forward at direction Angle_ at speed Speed_

Can I get a visual of the pizza slice/field of view to show the direction of the Enemy object?
It can be possible although im not sure how.
I dont really see the need for it unless its part of the game itsself.

First of all i think it would be wize of you to determine what kind of movement you want for your Enemies.

Built in movements or a custom movement?
Do you have a clear idea of how your game is going to work?

Using a built in movement is easier and saves you alot of time and troubble.
Using a custom movement is smoother and looks alot nicer, but can cause you troubble down the road especially if your new to MMF2.