How do you use box2d extension?

Questions
1

I read the docs, can’t seem to figure it out. Went to chatgpt and they just told me to use local box2d = require "box2d.box2d" but defold saying /main/main.script The file '/box2d/box2d.lua' could not be found. and I don’t know much on cpp. So, there’s no in the imported extension. There’s no other lua files except utils.lua. I want to use it to draw physics shapes. I’m importing/fetching library https://github.com/d954mas/defold-box2d/archive/refs/tags/1.0.3.zip). I want to create runtime created physics shapes. Should there be like box2d file with lua bindings?

image

2

No need to use require for native extensions, they’re automatically available in all scripts. Looks like the documentation for that extension starts here:

1 Like
3

There are two main ways of doing this; either use Defold’s built in implementation of Box2D (simple): Spawn a game object containing a collisionobject component. Read more here: Physics in Defold

Or, if the shapes can’t be predefined, use this Box2D extension (advanced):

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4

can someone give simple script to render a shape using debug and apply gravity to a shape? Because, I’m struggling to figure out the box2d extension api based on d954mas and the position of object not changing:


--world (returns Box2dWorld)
--body def
--createbody
--shape
--debug draw

-- main.script

function init(self)
	
	self.world = box2d.NewWorld{
		gravity = vmath.vector3(0, -9.8, 0)
	}

	-- ground — static body
	self.ground = self.world:CreateBody {
		type = box2d.b2BodyType.b2_dynamicBody 
		, position = vmath.vector3(0, -100, 0),
	}
end

function update(self, dt)
	-- step the physics world
	self.world:Step(dt, 8, 3)

	-- update sprite positions from physics bodie
	print(self.ground:GetPosition())

end