Collision Detection: No bounce, gravity, friction?

In another form post, someone mentioned basic collision detection without gravity or friction, etc:

http://developer.anscamobile.com/forum/2010/04/23/discussion-about-how-speed-your-game

So that is what I am interested in! I just need to know when two sprites collide, is there a preferred method for doing this?

I think I’m kind of doing it now, like so:

local physics = require( “physics” )
physics.start()
physics.setGravity( 0, 0 )

local hero = display.newImage( “hero.png” )
hero.x = 50; hero.y = 50;

physics.addBody( hero, { density=0, friction=0, bounce=0 } )

But the weird thing that is happening is that when I added the physics my hero image is being offset a little from it’s original placement (x=50, y=50) even though I have set the gravity to zero, plus I guess there is probably overhead in all of those other properties which I do not need.

So how do I do just basic collision detection, or in the very least fix the problem with the offsetting of the image?

Thanks!

[import]uid: 8139 topic_id: 3408 reply_id: 303408[/import]

Anyone anyone? Does anyone know what the correct method is? [import]uid: 8139 topic_id: 3408 reply_id: 10301[/import]

yip, the object has to be a sensor.

[lua] physics.addBody( cometL, { friction=0, bounce=0, isSensor = true, filter= { categoryBits = 1, maskBits = 2 }} )[/lua] [import]uid: 5712 topic_id: 3408 reply_id: 10345[/import]