Physics

Physics
#1

Hi All

would like a character walk around and have collisions with static walls, but if i set my character to static they have no visible collisions, but if i set my character to dynamic the collisions are great but my sprite rotates as in collides?

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

 

local player = display.newImage(“beer.png”)–display.newRect(display.contentWidth*0.5,display.contentHeight*0.5,32,32)
player:setFillColor(53, 115, 47)
player.name = “player”
player.x = 100
player.y = 100
–physics.addBody(player, {isSensor = true})
physics.addBody( player, “dynamic” , { density=0.0, friction=0, bounce=0 } )
–player:setStrokeColor(180, 180, 180)

 

local walls = display.newGroup()

 

local function AddWall(x,y,w,l)

 

walls:toFront()

 

local wall = display.newRect(x,y,w,l) --display.newImage(“beer.png”)
wall.name = “wall”
–wall.x = math.floor(math.random() * (display.contentWidth - 32))
–wall.y = math.floor(math.random() * (display.contentHeight - 32))
physics.addBody(wall, “static”, {density = 0.0, friction = 0, bounce = 0})
walls.insert(walls, wall)
end

 

AddWall(50,50,32,32)

 

local posx = 0
local posy = 0

 

local function MovePlayer()

 

player.x = player.x + posx
player.y = player.y + posy

 

if player.y < 0 then
player.y = 100
level2()
end

 

end
Runtime:addEventListener( “enterFrame”, MovePlayer );

 

local left = false
local right = false

 

local function ControlPlayer(event)

 

 if event.x < player.x then
 left = true
 right = false
 posx = -3
 elseif event.x > player.x then
 right = true
 left = false
 posx = 3
 else
 posx = 0
 end

 

 if event.y < player.y then
 posy = -3
 elseif event.y > player.y then
 posy = 3
 else
 posy = 0
 end
 
if event.phase == “ended” then
posx = 0
posy = 0
left = false
right = false
end

 

end
Runtime:addEventListener( “touch”, ControlPlayer )

#2

You can set isFixedRotation to true to keep the physics objects from rotating. Remember to declare it after your create the physics object:

http://docs.coronalabs.com/api/type/Body/isFixedRotation.html

#3

Thank you Panc, any idea how to stop the object do that bounce back to the non colliding position?

#4

Can you explain a bit more about your second issue? I’m not familiar with what you mean by “bounce back to the non colliding position”.

#5

hi Panc

my player - player, “dynamic” , { density=0.0, friction=0, bounce=0 } )

enters the static wall approx 3 pixels, i am moving player 3 pixels at a time

and when collision registers the player is then moved back(causes a bounce back) from inside the wall so it does not collide anymore.

can i stop the player dead when he comes in contact with the wall?

am i using wrong method of moving? would transition stop the object the instant it collides.

i am trying to create a usable collision for statics and moving objects, classic sprite to sprite collision but using the physics to check this for me rather than write myselfe.

thx

#6

If you’re going for classic top-down point-and-click RPG movement (which it seems you are) using the physics engine is fine, albeit a bit noisy when considering it’s a Runtime event. If you’re OK with that, then the physics option for detecting collisions is fine. I’d suggest checking out the pre-collision “contact” event, which will allow you to identify if an object is about to collide with another object:

http://www.coronalabs.com/blog/2012/11/27/introducing-physics-event-contact/

#7

You can set isFixedRotation to true to keep the physics objects from rotating. Remember to declare it after your create the physics object:

http://docs.coronalabs.com/api/type/Body/isFixedRotation.html

#8

Thank you Panc, any idea how to stop the object do that bounce back to the non colliding position?

#9

Can you explain a bit more about your second issue? I’m not familiar with what you mean by “bounce back to the non colliding position”.

#10

hi Panc

my player - player, “dynamic” , { density=0.0, friction=0, bounce=0 } )

enters the static wall approx 3 pixels, i am moving player 3 pixels at a time

and when collision registers the player is then moved back(causes a bounce back) from inside the wall so it does not collide anymore.

can i stop the player dead when he comes in contact with the wall?

am i using wrong method of moving? would transition stop the object the instant it collides.

i am trying to create a usable collision for statics and moving objects, classic sprite to sprite collision but using the physics to check this for me rather than write myselfe.

thx

#11

If you’re going for classic top-down point-and-click RPG movement (which it seems you are) using the physics engine is fine, albeit a bit noisy when considering it’s a Runtime event. If you’re OK with that, then the physics option for detecting collisions is fine. I’d suggest checking out the pre-collision “contact” event, which will allow you to identify if an object is about to collide with another object:

http://www.coronalabs.com/blog/2012/11/27/introducing-physics-event-contact/