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Help rendering a realistic road

edited February 2012 in Questions Posts: 2,820

Hello fellow coders,
As I mentioned before, I'm coding frogger and want a nice road. I want it to not be repudiative, so I don't want to tile an image, which i've done and looks alright, but not high enough for my standards. Right now, this is my code. On estimation, it would take 5.25 hours to render on my iPad 2.

Road = class() function Road:init() self.lanes = 10 self.lly = 0 --self.pavement = pavement() self.pavementdots = makeArray(WIDTH) for x = 1, WIDTH do for y = 1, HEIGHT/7*5 do self.pavementdots[x][y] = math.random(125) end end self.pavement = image(WIDTH,HEIGHT/7*5) for x = 1, WIDTH do for y = 1, HEIGHT/7*5 do clearOutput() print(x.."\n"..y) print(WIDTH.."\n".. HEIGHT) self.pavement:set(x,y,self.pavementdots[x][y], self.pavementdots[x][y], self.pavementdots[x][y],255) end end end function Road:draw() --draw the pavement sprite(pavement,0,HEIGHT - HEIGHT/7*6) --draw the lines strokeWidth(8) for j = 1,(self.lanes-1) do self.lly = (HEIGHT - HEIGHT/7*6)+((HEIGHT/7*5)/(self.lanes))*j for i = 0, WIDTH/50 do sline = i * 50 line(sline, self.lly,sline+25,self.lly) end end end function Road:touched(touch) end

I've tried different methods, but I can't get it fast. I'm wondering if meshing it is the solution... Although it's kind of hard for me to understand meshes... Can someone please help?


  • Posts: 2,820

    Can someone please create a good mesh tutorial please?

  • Possible solution

    Start with a small image and random it normally

    Copy it

    Rotate it 90 degrees

    Randomly randomize only a small percent of it


    Possibly combine all the images onto one image when done (and draw the lines over it)

  • also the noise example only takes ~30 seconds to render when tileSize = 1 on an IPad1

    you have to exit codea to stop it (sort of hard to time pressing exit between the long draws)

  • edited February 2012 Posts: 622

    Sorry for the triple post ...


    function setup()     pr = image(WIDTH,1)     for x = 1, WIDTH do         dot = math.random(125)         pr:set(x,1,dot,dot,dot,255)     end     ps = {}     for y = 1, HEIGHT do         ps[y] = math.random(WIDTH)     end end function draw()     for y = 1, HEIGHT do         sprite(pr,(WIDTH/2)-ps[y],y)         sprite(pr,WIDTH+(WIDTH/2)-ps[y],y)     end end
  • Posts: 2,820

    Oh... Thanks. I forgot about noise.

  • Posts: 2,820

    I'll try that put when I get a chance.

  • NatNat
    Posts: 143

    Maybe the array creation is the problem. You create a huge array of random numbers, then use those numbers to set pixels in the image, and then never use the array again. Why not just set the pixel components to random numbers and not use an array at all?

  • edited February 2012 Posts: 622

    thx @nat, I was wondering why mine was so much faster. I thought it was just the reuse of a 1 pixel tall image, randomly stacked on itself, but, the direct random may have been a big boost as well.

  • Posts: 2,820

    Generating noise is working very well :-) Thanks guys!

  • Posts: 159

    @Zoyt I just put this together, not sure if it's any use? You can specify a road's x, y, width, height, 'scale factor' (basically the size of the pixels that make up the road's texture), and an optional number of lanes.

    --# Main
    function setup()
        road1 = Road(WIDTH/2, 200, WIDTH, 250, 1, 5)
        road2 = Road(WIDTH/2, 450, WIDTH, 100, 2)
        road3 = Road(WIDTH/2, 600, WIDTH, 100, 4)
    function draw()
        background(56, 201, 15, 255)
    --# Road
    RoadLineHeight = 2    -- base height of road markings
    RoadLineWidth = 40    -- width of each road marking
    RoadLineGap = 40      -- gap between each road marking
    Road = class()
    function Road:init(x,y,w,h,scaleFactor,lanes)
        self.x = x
        self.y = y
        self.s = scaleFactor    -- default of 2 - change to alter 'blockiness'
        if (not self.s) then self.s = 2 end
        self.lanes = lanes
        if (not self.lanes) then self.lanes = 2 end
        self.img = image(w, h)    -- our road image!    
    function Road:draw()
        sprite(self.img, self.x, self.y)
    function Road:render()
        -- for each block in the road    
        for xx = 1, self.img.width, self.s do
            for yy = 1, self.img.height, self.s do
                -- pick a random grey
                local grey = math.random(30) 
                -- fill in a scaleFactor x scaleFactor block of pixels
                for xoffset = 0, self.s-1 do
                    for yoffset = 0, self.s-1 do
                        self.img:set(xx+xoffset, yy+yoffset, grey, grey, grey, 255)
        -- finally, draw on the markings
        stroke(255, 241, 0, 255)
        if self.lanes > 1 then
            local gap = self.img.height / self.lanes
            for i = 0, self.lanes-1 do
                local lineStart = RoadLineGap
                while (lineStart < self.img.width) do
                    line(lineStart, gap * i, lineStart+RoadLineWidth, gap * i)
                    lineStart = lineStart + RoadLineWidth + RoadLineGap
  • Posts: 2,820

    Wow. Thanks @frosty. I'll try it out. As you may be able to tell, I'm picky w my graphics

  • We should make this into a side contest, which method is fastest. Mine is a bit of a cheat since it's not a parameterized class, so, it would be hard to tell.

  • Posts: 2,820

    Haha. I think I'll try it and tell you guys.

  • Posts: 159

    Mine takes a little bit of time to create the road in the first place, but it's then rendered to a single image so drawing it is as fast as drawing any other sprite.

    Here's a quick image:


  • Posts: 2,820

    Most beautiful - @frosty :-) Much better looking than my meathod with darkening noise. Speed?... I'll see. An frosty, what ups are you using?

  • Posts: 2,820

    Haha. Can't wait to release this M rated version of Frogger :-)

  • Posts: 159

    @Zoyt ups?

  • Posts: 2,820

    Sorry. iPad @frosty

  • Posts: 159

    Oh, still an iPad 1 at the moment. Can't wait for the 3 to be released! :)

  • Posts: 2,820

    I actually don't have my own iPad yet. I'm waiting for a 64G iPad 3. You getting one?

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