Trouble With Shadows / Raycasting with Physics and Shaders
Posted: Mon Sep 03, 2018 9:59 pm
I am trying to set up a extremely basic shadow system using physics (for raycasting shapes) and shaders (for the shadows). This is what I have so far but I am stuck on a couple things.
1. How do I get my array of shadow/bright from lua into the shader? I have heard of Shader:send() but it says it only supports vectors of up to 4 variables. I suppose I could try to send a single extremely long number (like 01001111000...) instead of an array, but that sounds very inefficient.
2. I am getting a strange error with physics (and googling it doesn't help):
main.lua (should be able to run on its own but definitely has some bugs)
I was hoping somebody could help me out with these two issues.
Also, is this a terrible way to add shadows to my game? I feel like there is probably a much better/cleaner way of doing this.
1. How do I get my array of shadow/bright from lua into the shader? I have heard of Shader:send() but it says it only supports vectors of up to 4 variables. I suppose I could try to send a single extremely long number (like 01001111000...) instead of an array, but that sounds very inefficient.
2. I am getting a strange error with physics (and googling it doesn't help):
Code: Select all
Error
main.lua:33: Box2D assertion failed: r.LengthSquared() > 0.0f
Traceback
[C]: in function 'rayCast'
main.lua:33: in function 'draw'
[C]: in function 'xpcall'
Code: Select all
function love.load()
love.physics.setMeter(25)
world = love.physics.newWorld(0,0,true)
objects = {}
objects.obstacle = {}
objects.obstacle.body = love.physics.newBody(world, 200, 200)
objects.obstacle.shape = love.physics.newRectangleShape(50, 50)
objects.obstacle.fixture = love.physics.newFixture(objects.obstacle.body, objects.obstacle.shape)
objects.lightSource = {}
objects.lightSource.body = love.physics.newBody(world, 350, 250)
objects.lightSource.shape = love.physics.newCircleShape(10)
objects.lightSource.fixture = love.physics.newFixture(objects.obstacle.body, objects.obstacle.shape)
myShader = love.graphics.newShader[[
vec4 effect( vec4 color, Image texture, vec2 texture_coords, vec2 screen_coords ){
vec4 pixel = Texel(texture, texture_coords);
if (true){
return vec4(pixel.r, pixel.g, pixel.b, 1);
}
else {
return vec4(pixel.r, pixel.g, pixel.b,0);
}
}
]]
end
function love.draw()
--perform raytracing for each pixel
isPixelLit = {}
for y=0, love.graphics.getHeight() do
for x=0, love.graphics.getWidth() do
collision = false
world:rayCast(objects.lightSource.body:getX(), objects.lightSource.body:getY(), x, y, worldRayCastCallback)
if(collision) then
isPixelLit[#isPixelLit+1] = 0
else
isPixelLit[#isPixelLit+1] = 1
end
end
end
--send the pixel table to the shader
--not sure how to do this...
love.graphics.setShader(myShader) --draw something here
love.graphics.setColor(1, 0, 0)
love.graphics.circle("fill", objects.lightSource.body:getX(), objects.lightSource.body:getY(), objects.lightSource.shape:getRadius())
love.graphics.setColor(0, 1, 0)
love.graphics.polygon("fill", objects.obstacle.body:getWorldPoints(objects.obstacle.shape:getPoints()))
love.graphics.setShader() --disable the shader for the remaining objects to draw
end
function love.update(dt)
world:update(dt)
end
function worldRayCastCallback()
collision = true
return 1
end
Also, is this a terrible way to add shadows to my game? I feel like there is probably a much better/cleaner way of doing this.