To Hittest or Not To Hittest

[mordormaster]

Hittesting has become pretty much the most important part of my game. So ive ended up putting 62 hittests on one of four secsions per enemy. So understandably, lag central, anybody got a more efficant way of doing this code.

onClipEvent (enterFrame) {
if (_root.floor.ai1.hitTest (this)) {
_root.floor.enemy1._y+=15
}
if (_root.floor.ai2.hitTest (this)) {
_root.floor.enemy1._y+=15
}
if (_root.floor.ai3.hitTest (this)) {
_root.floor.enemy1._y+=15
}
if (_root.floor.ai4.hitTest (this)) {
_root.floor.enemy1._y+=15
}
if (_root.floor.ai5.hitTest (this)) {
_root.floor.enemy1._y+=15
}
}

[dandylion13]

Hello,

Can you explain what you need your collision detection to do?

[OmniNL]

I know Tonypa had some great tutorials with hittests, although i think they are more tile related.
http://www.tonypa.pri.ee/tbw/start.html

He doesn't use hitTest() at all, but uses the corners of the MC to detect others.
Hope that helps a bit

[mordormaster]

I have my Map movieclip called Floor, i have my enemy called Goblin_Swordsman_1 and i have my enemy hittesting part. There are four secsions. As the bottom secsion touches an object it moves the goblin up by 15 pixels. This just about works. I have several objects that the goblins shouldn't be able to walk through. I call these Ai1 Ai2 etc. Any ideas? If you need an .Fla il post.

[TOdorus]

Introduce a broadphase.

A simple one would be to first do a circle vs circle check with math. Just give your objects a radius which encompasses the whole graphic and first check if those circles are overlapping and only then perform a more expensive hittest.

Another way is to use a grid, but this only saves with A LOT of objects. At the start of every update cycle you wipe the grid, then loop through every object update their velocities and register them with the gridcell they're in. Finally you loop through all the objects again to do collision detection and resolvement, but now you only need to check the objects in the occupied cell and it's neighbors.

[mordormaster]

Thank you very much il check them out, last question really, i have my object floor.enemy1.Inner_1 and i want it to hittest floor.map. How come it does the perimeter instead of the actual object?

[rrh]

Because you're hitTesting two objects on each other and doing a full shape comparison could be a huge performance hit. You can get the full shape if you hitTest a point and an object.

[mordormaster]

How would i do that then ive got the layers laid out for it now, ive fixed the ai chasing and patroling code now so if you could show me how to do that id appreciate it alot

[mordormaster]

Une bump

[rrh]

First you look up hitTest in the actionscript dictionary:
http://www.adobe.com/support/flash/a...ionary534.html

Pay special attention to any talk about the shape flag.