Collision with backdrop not working

[timcclayton]

Hello.

I have a problem whereby an enemy is tracking the player and it is set to "Bounce" when it collides with a backdrop object. It does work most of the time, but sometimes the enemy does walk right through a backdrop object.

I have set "collides with the background" and also "is overlapping a backdrop" but even the combination of both doesn't work.

Does anyone have any experience of this?

Thanks in advance,
Tim.

[theninjablooper]

is the backdrop set to obstacle in its properties?

[keokeo]

Also are you sure that they are both on the same layer?

[timcclayton]

Thanks for the replies.

Yes all the backdrop objects are set to "Obstacle" and there is only 1 layer in the game.

[Pineapple]

Just a guess, but try checking your code to see if there are any conditions that might conflict with making the enemy bounce. for example, having the enemy move in a specific direction.

[timcclayton]

Yes I was going to post the basic AI following routine to see if that might be causing it. It is:

IF X position of "Enemy" < X("Player") THEN set X position to X("Enemy")+1

and the same goes for the other 3 directions (i.e. "> X", "< Y" and "> Y" (hope that all makes sense!).

[Pineapple]

you might need to do something to limit the movement condition, such as:

IF X position of "Enemy" < X("Player") THEN set X position to X("Enemy")+1
& Internal Flag 1 is off

Then add a condition like:
Enemy collides with wall, set flag 1 on, set alterable value A to 25

Flag 1 is on, subtract 1 from Alterable Value A

Alterable value A is lower than zero, set flag 1 off.

That will temporarily turn off the "follow" AI to allow it to bounce properly.

[timcclayton]

Thanks for that. I have implemented it but unfortunately it still runs through some objects as before.

It seems to be a bug since I can't seem to find a fault in my logic here - or maybe it is the way I am moving the "enemy" that could be improved?

[timcclayton]

Can anyone else please offer some assistance for this bug? I really don't want to abandon this project, I have put too many hours into it!

[Konidias]

I would hold off on calling it a "bug" just yet... That just means you've passed the blame on to the program and not yourself... Which pretty much leaves you stuck because you've given up fixing it.

I would suggest saving a copy of your project and then removing stuff that you think might be causing a conflict, one at a time. (like the enemy movement) If the problem goes away, you will have figured out what is causing it by process of elimination.

Once you find out what is causing it, then it becomes a lot easier to fix.