Physics isn't working properly!

Solar2D General Questions/Discussion
#21

Please do the following and I’ll take a look:

  1. Get rid of the massive code dump at the top.

  2. Write a new short example in a separate main.lua file with just these parts:

  • physics initialization
  • drag listener (seems like you want to do this)
  • object creation (no PNGs, just rects and circles)
  • addEventListener() calls

i.e. Minimize the problem so I don’t have to copy all your code, modify it, etc. just to look at the problem.  

  1. Then, if you haven’t found the problem at that point, paste the code back into your original post and make sure it is well formatted and indented.  
  • remove tabs before pasting and replace with three spaces
  • no long sections of blank lines
  • proper indentation so I can logically separate functions, if statements, etc. w/o needing to read every line
  1. Post below saying its updated. 

I’ll be watching.

#22

thanks for the reply !! well see if i put the code into main.lua without the composer setup it work perfect… as soon as i put in composer and try adding physics to the floor it starts messing things up…

#23

Look ive made it a simple as i possibly can and its still not working correctly …

local composer = require( "composer" ) local scene = composer.newScene() local physics = require("physics" ) physics.setScale( 30 ) physics.setGravity( 0, 0 ) physics.start( ) physics.setDrawMode( "hybrid" ) function scene:create( event ) local sceneGroup = self.view local BackGround = display.newImageRect("BackGround.png", 1080, 1920) local floor = display.newImageRect("floor.png", 351, 32) floor.x = display.contentWidth \* 0.5 floor.y = 510 physics.addBody("static") end -- Listener setup scene:addEventListener( "create", scene ) scene:addEventListener( "show", scene ) scene:addEventListener( "hide", scene ) scene:addEventListener( "destroy", scene ) -- ------------------------------------------------------------------------------- return scene

if you remove “physics.addBody(“static”)” then theres no error but if you add it it gives an error in the cosole… and the physics doesnt work

#24

if i put this code into the main.lua it gives me an error for this

local physics = require("physics" ) physics.setScale( 30 ) physics.setGravity( 0, 0 ) physics.start( ) physics.setDrawMode( "hybrid" ) local BackGround = display.newImageRect("BackGround.png", 1080, 1920) local floor = display.newImageRect("floor.png", 351, 32) floor.x = display.contentWidth \* 0.5 floor.y = 510 physics.addBody("static") \<----------- that
#25

In your shortened example, the error you are getting is because you don’t specify a object to add a physics body to. Instead of [lua]physics.addBody(“static”)[/lua] try [lua]physics.addBody(floor, “static”)[/lua]

Now that may or may not fix your original problem, but at the very least it’s an issue that would cause an error in your shortened test scenario.

Keep plugging away - these frustrating situations often yield the best learning experiences, so don’t let it get you down!

#26

Dang!  I missed responding, but Jason is right, got tell it what object to add the body to.

-Ed

#27

well the

physics.addBody(floor, “static”)

worked in the main.lua but didnt in the

local composer = require( "composer" ) local scene = composer.newScene() local physics = require("physics" ) physics.setScale( 30 ) physics.setGravity( 0, 0 ) physics.start( ) physics.setDrawMode( "hybrid" ) function scene:create( event ) local sceneGroup = self.view local BackGround = display.newImageRect("BackGround.png", 1080, 1920) local floor = display.newImageRect("floor.png", 351, 32) floor.x = display.contentWidth \* 0.5 floor.y = 510 physics.addBody("static") end -- Listener setup scene:addEventListener( "create", scene ) scene:addEventListener( "show", scene ) scene:addEventListener( "hide", scene ) scene:addEventListener( "destroy", scene ) -- ------------------------------------------------------------------------------- return scene
#28

Three things:

  1. Please re-edit after posting code and remove the extra blank lines.  This will make code posts more legible.

  2. What editor are you using?  I’m seeing lots of code pastes like this (extra lines) and I suspect the common factor is the editor folks are using.

  3. You made the same mistake:

    physics.addBody(“static”)

should be:

physics.addBody( floor, "static")
#29 
local composer = require( "composer" ) local scene = composer.newScene() -------------------------------------------- local physics = require("physics" ) physics.setScale( 30 ) physics.setGravity( 0, 0 ) physics.start( ) physics.setDrawMode( "hybrid" ) --------------------------------------- function scene:create( event ) local sceneGroup = self.view local BackGround = display.newImageRect("BackGround.png", 1080, 1920) local floor = display.newImageRect("floor.png", 351, 32) floor.x = display.contentWidth \* 0.5 floor.y = 510 physics.addBody(floor, "static") end ------------------------------------------ -- Listener setup scene:addEventListener( "create", scene ) scene:addEventListener( "show", scene ) scene:addEventListener( "hide", scene ) scene:addEventListener( "destroy", scene ) -- ------------------------------------------------------------------------------- return scene

is that good? this is what i tried in my game.lua and it still doesnt start physics for the floor…

and im using Sublime Text 2

#30

ok so i figured it out… i put the floor image into my “did” part of my scene on the show scene and it worked but now its duplicating my objects… like scene show is duplicating objects heres the code…

local composer = require( "composer" ) local scene = composer.newScene() local physics = require( "physics" ) physics.start( ) physics.setDrawMode( "hybrid" ) function scene:create( event ) local sceneGroup = self.view local BackGround = display.newImageRect("BackGround.png", 1080, 1920) end function scene:show( event ) local sceneGroup = self.view local phase = event.phase if ( phase == "will" ) then elseif ( phase == "did" ) then local floor = display.newImageRect("floor.png", 351, 32) floor.x = display.contentWidth \* 0.5 floor.y = 510 physics.addBody( floor, "static" ) ----------------------------------------------- local circle = {} local spawnCircles = function () local FallDown = math.random(display.contentWidth \* 0.2, display.contentWidth \* 0.8 ) circle = display.newImageRect("circle.png", 31, 31 ) circle.x = FallDown circle.y = -70 physics.addBody( circle, "dynamic", {density = .01, friction = 0.5, bounce = 0.1 }) circle.gravityScale = 0.1 physics.setGravity( 0, 10 ) end myTimer = timer.performWithDelay( 2000, spawnCircles, -1) --1000 is the time end return true end -- Listener setup scene:addEventListener( "create", scene ) scene:addEventListener( "show", scene ) scene:addEventListener( "hide", scene ) scene:addEventListener( "destroy", scene ) -- ------------------------------------------------------------------------------- return scene

im also attaching images so you can try the code youself…

if you prefer i make a video please tell me thanks!

#31

Three things:

  1. Don’t init physics in a composer scene unless you absolutely need to.  Most times you can do it in main and simply adjust gravity or pause and restart physics later.

  2. Be sure you’e not starting physics multiple times and also that you’re not accidentally stopping it somewhere.  Starting multiple times is probably fine, but bad practice.

  3. This code should work:

main.lua

-- First init physics in main.lua local physics = require("physics" ) physics.start() -- Gotta start before ... physics.setGravity( 0, 0 ) -- ... setting gravity (you've been doing it backwards) physics.setDrawMode( "hybrid" ) --------------------------------------------------- -- Do what you normally do to load your scene here ---------------------------------------------------

yourscene.lua

local composer = require( "composer" ) local scene = composer.newScene() local physics = require("physics" ) -- still need to require in composer to use it. function scene:create( event ) local sceneGroup = self.view --Note: Another issue. You were not inserting your objects into the sceneGroup local BackGround = display.newImageRect( sceneGroup, "BackGround.png", 1080, 1920 ) local floor = display.newImageRect( sceneGroup, "floor.png", 351, 32 ) floor.x = display.contentWidth \* 0.5 floor.y = 510 physics.addBody( floor, "static" ) end ... rest of scene contents goes below
#32 
local composer = require( "composer" ) local scene = composer.newScene() local physics = require( "physics" ) physics.start( ) physics.setDrawMode( "hybrid" ) function scene:create( event ) local sceneGroup = self.view local BackGround = display.newImageRect("BackGround.png", 1080, 1920) end function scene:show( event ) local sceneGroup = self.view local phase = event.phase if ( phase == "will" ) then elseif ( phase == "did" ) then local floor = display.newImageRect("floor.png", 351, 32) floor.x = display.contentWidth \* 0.5 floor.y = 510 physics.addBody( floor, "static" ) ----------------------------------------------- local circle = {} local spawnCircles = function () local FallDown = math.random(display.contentWidth \* 0.2, display.contentWidth \* 0.8 ) circle = display.newImageRect("circle.png", 31, 31 ) circle.x = FallDown circle.y = -70 physics.addBody( circle, "dynamic", {density = .01, friction = 0.5, bounce = 0.1 }) circle.gravityScale = 0.1 physics.setGravity( 0, 10 ) end myTimer = timer.performWithDelay( 2000, spawnCircles, -1) --1000 is the time end return true end -- Listener setup scene:addEventListener( "create", scene ) scene:addEventListener( "show", scene ) scene:addEventListener( "hide", scene ) scene:addEventListener( "destroy", scene ) -- ------------------------------------------------------------------------------- return scene

well this code works for me and the only thing wrong with it is that it duplicates the balls… do you knwo why and how to fix it?

#33

It duplicates them because Show, phase "will’ is called every time you open the scene.  If you want to create once, create in the create() method of the scene manager.

Oh, and you’re still using an infinite timer?  I thought I mentioned that is a bad practice.

Call the spawner infinitely == spawn infinitely.

timer.performWithDelay( 2000, spawnCircles, -1)
#34

can you explain better how to stop it from duplicating? and then we will fix the timer?

#35

heres a video of whats happening 

https://youtu.be/S2Xv6lJahsk

@roaminggamer

#36

It seems to me you have multiple versions of this thread going on.  I just responded to a similar thread.  In the future, only as your question once and keep a single thread to get your answers.  When you have a different problem, start a new thread. 

Rob

#37

ya sorry i was just getting really confused… im marking this one solved…