Change position of collision circle?

Solar2D General Questions/Discussion
#1

Hi,

As you can see in the following image, I am not happy with the default physics circle’s position. I want to move it a little bit, How can i change it’s position???

radius.jpg

#2

You cannot. Circle is centered at image center.

#3

Then how do i change the center of the image, and will it change the circle’s position?

Thanks

#4

You just make image in such way that center is in point you want circle to be. For eg. add some alpha padding.

#5

The easiest way to to do something like this:

local function createPlayerLocation() player0 = hero.createHero() player0:setReferencePoint(display.CenterReferencePoint) player0.hitBox = display.newRect(0,0,26,16) physics.addBody(player0.hitBox, { density = 60.0, friction = 0.3, bounce = 0 }) player0.hitBox:setFillColor(0,0,0,0) player0.hitBox..x = 100 player0.hitBox..y = 200 player0.x = player0.hitBox.x player0.y = player0.hitBox.y end createPlayerLocation() -- more code for your app -- Here's your Runtime code: local function movingTime() -- Your regular Runtime code player0.x = player0.hitBox.x player0.y = player0.hitBox.y end Runtime:addEventListener("enterFrame", movingTime)

This will pin your character sprite to your physics object. 

#6

Hi @coolromin,

You may also opt to just draw a polygon “circle” using the shape method, which could be drawn “non-center” if you wish. This could be, at most, an 8 sided shape (so, an octagon), but you could draw two halves side-by-side for a more accurate circle. But, it looks like you could go even more detailed regardless, and trace these figures with a more accurate shape than a circle.

See the physics body guide here:

http://docs.coronalabs.com/guide/physics/physicsBodies/index.html

Best regards,

Brent

#7

You cannot. Circle is centered at image center.

#8

Then how do i change the center of the image, and will it change the circle’s position?

Thanks

#9

You just make image in such way that center is in point you want circle to be. For eg. add some alpha padding.

#10

The easiest way to to do something like this:

local function createPlayerLocation() player0 = hero.createHero() player0:setReferencePoint(display.CenterReferencePoint) player0.hitBox = display.newRect(0,0,26,16) physics.addBody(player0.hitBox, { density = 60.0, friction = 0.3, bounce = 0 }) player0.hitBox:setFillColor(0,0,0,0) player0.hitBox..x = 100 player0.hitBox..y = 200 player0.x = player0.hitBox.x player0.y = player0.hitBox.y end createPlayerLocation() -- more code for your app -- Here's your Runtime code: local function movingTime() -- Your regular Runtime code player0.x = player0.hitBox.x player0.y = player0.hitBox.y end Runtime:addEventListener("enterFrame", movingTime)

This will pin your character sprite to your physics object. 

#11

Hi @coolromin,

You may also opt to just draw a polygon “circle” using the shape method, which could be drawn “non-center” if you wish. This could be, at most, an 8 sided shape (so, an octagon), but you could draw two halves side-by-side for a more accurate circle. But, it looks like you could go even more detailed regardless, and trace these figures with a more accurate shape than a circle.

See the physics body guide here:

http://docs.coronalabs.com/guide/physics/physicsBodies/index.html

Best regards,

Brent