Why my physic not work?

Questions
1

I made a program to try about Codea physic, but it won’t work. Can someone tell my why, and how to use it? Thank you. :slight_smile:

here is the code:

-- Physic

-- Use this function to perform your initial setup
function setup()
    rectMode(CENTER)
    ellipseMode(CENTER)
    parameter.integer("y",0,1000,0)
    a,b = physics.body (POLYGON,vec2(-50,-50),vec2(-50,50),vec2(50,-50),vec2(50,50)),physics.body (POLYGON,vec2(-50,-50),vec2(-50,50),vec2(50,-50),vec2(50,50))
    a.x,a.y,a.interpolate,a.awake = WIDTH/2,2000,true,true
    b.x,b.y = WIDTH/2,HEIGHT/5
    b.type = STATIC
    stroke(0, 0, 0, 255)
    strokeWidth(3)
end

-- This function gets called once every frame
function draw()
    b.y = y
    strokeWidth(3)
    local O = {a,b}
    print (1/DeltaTime)
    background(255, 255, 255, 255)
    fill(136, 207, 224, 255)
    for i = 1 , 2 do
        pushMatrix()
        translate(O [i].x,O [i].y)
        rotate(O [i].angle)
        rect(0,0,100)
        popMatrix()
    end
end
2

Can you please try to explain what exactly you are trying to do? Maybe then we can help you more

3

@EvanDavis I just what to learn about physic, but I have come problem with that.

4

Can you speak English well? Or would you like to try a translator?

5

I can’t understand you, sorry.

6

@EvanDavis I need help with Codea physics, can you help me? Thank you. Sorry about my English.

7

In my experience (not much, but I’ve done some physics), codea’s physics engine doesn’t like to update while you’re manually changing the x or y position of a physics body. What this looks like is what you see when you move your static body around and the dynamic one doesn’t move. I don’t exactly know how to fix this, but I’ve gotten around it in the past by applying a minuscule linear impulse to the body and immediately cancelling it out by applying a miniscule linear impulse the exact opposite direction. I do this at the same time that I change the x or y value of a body and it seems to work. Hope this helps!

-Update: If you set a.sleepingAllowed = false and b.sleepingAllowed = false then most of your problems should be fixed. I’m still not sure about that box sliding into the other though. Good Luck!

8

@Attila717 Thank you very much! :slight_smile: I will try this! Thank you! As @EvanDavis says, my English is not good because I’m Chinese! Thank you for the help!

9

@Gai_Gai Here’s an example similar to what your code was trying to do. Look it over and if you have questions, just ask.

displayMode(FULLSCREEN)

function setup()
    rectMode(CENTER)
    
    physics.continuous=true
    
    physics.body(EDGE,vec2(0,0),vec2(WIDTH,0))  -- floor
    
    a=physics.body (POLYGON,vec2(-50,-50),vec2(50,-50),vec2(50,50),vec2(-50,50))
    a.x=WIDTH/4+51
    a.y=HEIGHT  
      
    b=physics.body (POLYGON,vec2(-50,-50),vec2(50,-50),vec2(50,50),vec2(-50,50))
    b.x=WIDTH/4
    b.y=300
    b.type=STATIC
    
    fill(135, 217, 224, 255)
    stroke(0)
    strokeWidth(3)
end

function draw()
    background(161, 223, 191, 255)    
    
    pushMatrix()
    translate(a.x,a.y)
    rotate(a.angle)
    rect(0,0,100,100)
    popMatrix()   
     
    rect(b.x,b.y,100,100)
end
10

@dave1707 Thank you very much. :smiley: