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3D Failure

in Code Sharing Posts: 174

--# Icosphere Icosphere = class() function Icosphere:init() -- Initial stuff self.faces = {} self.vertices = {} self.mesh = mesh() self.mesh.texture = "Planet Cute:Grass Block" self.iterationLevel = level self:initVertices() self:initFaces() -- Subdivide for i = 1, self.iterationLevel do self:subdivideFaces() end -- Fix mesh verts local ti = table.insert local cl = color local r = math.random local ve = {} local c = {} local tx = {} local main = cl(r(0,255),r(0,255),r(0,255)) for i,v in ipairs(self.faces) do -- Change color slightly from original clr = cl(main.r+r(-50,50),main.g+r(-50,50),main.b+r(-50,50)) -- Vertices ti(ve,v[1]) ti(ve,v[2]) ti(ve,v[3]) -- Colors ti(c,clr) ti(c,clr) ti(c,clr) -- Texture (disabled for now) --ti(tx,vec2(0,0)) --ti(tx,vec2(1,0)) --ti(tx,vec2(0.5,0.5)) end self.mesh.vertices = ve self.mesh:setColors(color(60,150,40)) self.mesh.colors = c -- self.mesh.texCoords = tx -- Uncomment this line to show an image on each of the faces end function Icosphere:initVertices() local t = (1 + math.sqrt(5)) / 2 local p = vec3 local function v(...) table.insert(self.vertices,p(...):normalize()) end v(-1, t, 0) v( 1, t, 0) v(-1,-t, 0) v( 1,-t, 0) v( 0,-1, t) v( 0, 1, t) v( 0,-1,-t) v( 0, 1,-t) v( t, 0,-1) v( t, 0, 1) v(-t, 0,-1) v(-t, 0, 1) end function Icosphere:subdivideFaces() local faces2 = {} local function gm(v,v2) return ((v+v2)/2):normalize() end local ti = table.insert for i,tri in ipairs(self.faces) do local a = gm(tri[1],tri[2]) local b = gm(tri[2],tri[3]) local c = gm(tri[3],tri[1]) ti(faces2,{tri[1],a,c}) ti(faces2,{tri[2],b,a}) ti(faces2,{tri[3],c,b}) ti(faces2,{a,b,c}) end self.faces = faces2 end function Icosphere:initFaces() local function f(...) table.insert(self.faces,self:triangleIndices(...)) end f(1,12,6) f(1,6,2) f(1,2,8) f(1,8,11) f(1,11,12) f(2,6,10) f(6,12,5) f(12,11,3) f(11,8,7) f(8,2,9) f(4,10,5) f(4,5,3) f(4,3,7) f(4,7,9) f(4,9,10) f(5,10,6) f(3,5,12) f(7,3,11) f(9,7,8) f(10,9,2) end function Icosphere:triangleIndices(i1,i2,i3) return { self.vertices[i1], self.vertices[i2], self.vertices[i3] } end function Icosphere:draw() pushMatrix() scale(Zoom) self.mesh:draw() popMatrix() end --# Main -- 3D Sphere -- Use this function to perform your initial setup function setup() print("Hello Spheres!") level = 0 i = Icosphere() parameter.integer("level",0,10,1,function() local pstr = string.format("Creating %d faces...",20*4^level) if level > 4 then pstr = pstr.." (may take a while)" end print(pstr) i:init() -- init again with new level collectgarbage() end) parameter.integer("Zoom",1,40) slide = vec2(0,0) camX, camY, camZ = -50,-50,-50 rotMatrix = matrix() end -- This function gets called once every frame function draw() -- This sets a light background color background(226, 226, 235, 255) -- Do your drawing here perspective(45) camera(camX,camY,camZ,0,0,0,1,0,0) pushMatrix() applyMatrix(rotMatrix) i:draw() popMatrix() if slide:len()>0 then rotMatrix = rotMatrix:rotate(slide:len(),slide.x,slide.y,0) end slide = slide * 0.9 end function touched(touch) slide.y = touch.deltaY slide.x = touch.deltaX end -- Useless functions (did not work for rotation) function rotateZ(x,y,z,r) local l = math.sqrt(x^2+y^2) local nx = x*math.cos(r) - y*math.sin(r) local ny = y*math.cos(r) + x*math.sin(r) return nx,ny,z end function rotateY(x,y,z,r) local l = math.sqrt(x^2+y^2) local nz = z*math.cos(r) - x*math.sin(r) local nx = x*math.cos(r) + z*math.sin(r) return nx,y,nz end function rotateX(x,y,z,r) local l = math.sqrt(x^2+y^2) local ny = y*math.cos(r) - z*math.sin(r) local nz = z*math.cos(r) + y*math.sin(r) return x,ny,nz end

Unfortunately, rotation in 3D is not as easy as it seems. Neither is lighting. I tried shaders, but everything turns out black or invisible (because my understanding of shaders is limited). I wanted to make a globe from which points could be selected, for level selection and other purposes.
Final questions:
* How can I make touch rotation easier (for the user)?
* Is there a simple shader to render my sphere mesh as a wireframe?
* Are there any good 3d lighting tutorials out there (possibly for Codea)?

Thanks in advance!



  • dave1707dave1707 Mod
    edited August 2017 Posts: 6,486

    @em2 Maybe when Codea Craft is released, 3D will be a lot easier for what you want to do. As for rotation, see the reference for rotate(angle,x,y,z) that allows you to rotate the object some degrees in the x or y or z axis or a combination of them. Nice example, I crash at about level 8 on my iPad Air.

    EDIT: On my iPad Pro, it crashes at level 10.

  • dave1707dave1707 Mod
    Posts: 6,486

    @em2 Here's an example that I probable posted in the past that shows the use of rotate for a sphere.

    function setup()
    function setup1()    
        for n=0,N do
            for m=0,M do
                x=10 * math.sin(math.pi * m/M) * math.cos(2*math.pi * n/N)
                y=10 * math.sin(math.pi * m/M) * math.sin(2*math.pi * n/N)
                z=10 * math.cos(math.pi * m/M)
        for n=0,N-1 do
            for m=0,M-1 do
        for z=1,#sph,6 do
            for q=1,6 do
    function draw()  
        background(40, 40, 50)
  • Posts: 2,011

    @em2 it's true that Codea Craft is about to revolutionise 3D in Codea.

    I'm not sure whether Craft includes a wireframe shader. My trench run game from a couple of years' back has a wireframe mode. The installer here should still work:

    If you can't wait for Craft (and there's no harm in learning how 3D works under the hood) @Ignatz put together some great ebooks on shaders and lighting in Codea, find them at

  • Posts: 147

    Craft seems like it'll be awesome, but I don't think I'll have access to it's features as I only have Codea Scratchpad. For some reason whenever I try buying an app on the Appstore, I have to answer security questions that I don't even remember setting up :\ so I could never buy Codea. Maybe I can call Apple or something. I'm not really sure. I'm at the point where I'd do almost anything for the full version of Codea

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