LÖVE

Posted: **Sat Sep 05, 2009 9:48 pm**

Huh. I'm trying to use love's physics, but I just discovered that any velocity numbers > than 200 are chopped down to 200. I don't know why, I just know that they are. And that it's annoying. Moving faster than 200 is a must.

Here's a love file that demonstrates this cropping velocity down to 200. If I'm missing something, please tell me now.

Posted: **Sun Sep 06, 2009 1:03 am**

Huh, also: love crashes if a world has 2000 or more physics objects. (actually, I think it's 2048)

Posted: **Sun Sep 06, 2009 2:03 am**

whats the objects mass?

Posted: **Sun Sep 06, 2009 3:38 am**

Re: Osgeld
the mass is 1, but that shouldn't matter to setVelocity()

Posted: **Sun Sep 06, 2009 4:13 am**

It looks like the 200 m/s limit is a feature of the underlying "Box2D" so you have to scale your simulation to within the limits.

Posted: **Sun Sep 06, 2009 4:44 am**

Code: Select all

function update(dt)
    world:update(X * dt)
end

Posted: **Sun Sep 06, 2009 5:03 am**

doh, that is a clever fix. I still have issues with 2000+ physics objects though.. I guess I'll just have to have fewer objects..

Posted: **Sun Sep 06, 2009 5:09 am**

you can have smaller physical worlds, depending on your need for accuracy and scale to shown perspectives, its all a matter of scale

PS: just cause I was bored ....

Code: Select all

function load()
	love.graphics.setFont(love.default_font,12)

	world = love.physics.newWorld(1000,1000)
	body  = {}

	for i = 1, 6 do
		table.insert(body, love.physics.newBody(world,100,(i *100)))
	end
		
	for i = 1, #body do
		body[i]:setVelocity((5 * i),0)
	end
end

function update(dt)
	world:update(50 *dt)
end

function keypressed(key)
	if key == love.key_r then 
		world = nil
		body  = nil
		collectgarbage("collect")
		load()		
	end
end

function draw()
	for i = 1, #body do
		local x, y = body[i]:getPosition()
		love.graphics.circle(love.draw_fill,x,y,10)
		love.graphics.draw('Expected Speed: ' .. (i * 5) ,10,y-15)
		love.graphics.draw('Actual Speed: ' .. body[i]:getVelocity() ,10,y)
	end
	
	love.graphics.draw('R to restart',10,10)
end

Posted: **Sun Sep 06, 2009 11:40 am**

From b2Settings.h:

Code: Select all

/// The maximum linear velocity of a body. This limit is very large and is used
/// to prevent numerical problems. You shouldn't need to adjust this.
const float32 b2_maxLinearVelocity = 200.0f;

This limit is very large if you use Box2D as it's intended. In LÖVE 0.5.0, one meter is 1px (not good). In LÖVE 0.6.0 you can set how many pixels one meter should be.

Also b2Settings.h:

Code: Select all

const int32 b2_maxProxies = 2048;

That's the limit of how many shapes you can have.

Posted: **Sun Sep 06, 2009 11:45 am**

rude wrote:In LÖVE 0.5.0, one meter is 1px (not good)

You can change that with CAMERAs. That's how we did it in LovelyBigPlanet.

LÖVE

Max velocity = 200, why?

Max velocity = 200, why?

Re: Max velocity = 200, why?

Re: Max velocity = 200, why?

Re: Max velocity = 200, why?

Re: Max velocity = 200, why?

Re: Max velocity = 200, why?

Re: Max velocity = 200, why?

Re: Max velocity = 200, why?

Re: Max velocity = 200, why?

Re: Max velocity = 200, why?