Hello, everyone!
I’m currently working on a Minecraft look-alike FPS and I would like to add a moon to the sky (just a flat mesh with a moon texture). However, I’m not sure what the proper way of doing this is. I feel that to draw a really large mesh that’s really far away sounds a bit ridiculous, but I can’t think of anything else. I’m thinking I should draw a small mesh that circles around and follows the player at a short distance but the problem with that is that meshes behind the moon will appear… well, behind the moon. How can I tell openGL to draw the moon behind everything else? Is this possible? Is there a better way to make a moon? Thanks in advance, guys! 
First, it doesn’t need to be a 3D moon, you can just use a 2D picture. You will need to rotate it to face the camera, if your camera is moving about, but that’s not hard.
Then all you need to do is set the z value of the moon to be far away so it is drawn behind everything else.
If the moon is static (doesn’t rise and set within a day/ night cycle), then you could use a skybox which has a moon painted on it.
I made the moon and it looks great! I would like to post a video but I don’t know how… 
- codea has a build-in gameplay video recorder
- you can publish the recorded video to youtube and then post the link here (which should get parsed to a inline-video automatically by the forum software)
You can give me the moon code, and I’ll post a video
The code is too long to post in the forums. It passes the character limit.
The share it via GitHub
I don’t have a github account or a pastebin account.
Okay, how do I use github?
After I’ve pasted the code into a gist, do I press “create public gist”?
Yup
By the way, sorry @se24vad, @TokOut, @MattthewLXXIII and @yojimbo2000 for wasting your time sometimes I ask too many questions when I could have looked up my questions…
@Kolosso Here some code I modified to make a 3D sphere look kind of like a moon.
displayMode(FULLSCREEN)
function setup()
ang=0
createMoon()
end
function createMoon()
tab={}
r=30 --moon radius
M,N=40,60
for n=0,N do
tab[n]={}
for m=0,M do
x=r * math.sin(math.pi * m/M) * math.cos(2*math.pi * n/N)
y=r * math.sin(math.pi * m/M) * math.sin(2*math.pi * n/N)
z=r * math.cos(math.pi * m/M)
tab[n][m]=vec3(x,y,z)
end
end
sph={}
for n=0,N-1 do
for m=0,M-1 do
table.insert(sph,tab[n][m]) table.insert(sph,tab[n][m+1])
table.insert(sph,tab[n+1][m+1]) table.insert(sph,tab[n][m])
table.insert(sph,tab[n+1][m]) table.insert(sph,tab[n+1][m+1])
end
end
cols={}
for z=1,#sph,6 do
v=math.random()/8+.7
col=vec4(v,v,v,1)
for c=1,6 do
table.insert(cols,col)
end
end
moon=mesh()
moon.vertices=sph
moon.colors=cols
end
function draw()
background(40, 40, 50)
perspective(15)
camera(2000,0,0,0,0,0,0,1,0)
rotate(90,1,0,0)
rotate(-30,0,1,0)
ang=(ang+.2)%360
rotate(ang,0,0,1)
moon:draw()
end
Sun 
displayMode(FULLSCREEN)
function setup()
ang=0
createMoon()
timeChangePixels = 0
end
function createMoon()
tab={}
r=130 --moon radius
M,N=40,60
for n=0,N do
tab[n]={}
for m=0,M do
x=r * math.sin(math.pi * m/M) * math.cos(2*math.pi * n/N)
y=r * math.sin(math.pi * m/M) * math.sin(2*math.pi * n/N)
z=r * math.cos(math.pi * m/M)
tab[n][m]=vec3(x,y,z)
end
end
sph={}
for n=0,N-1 do
for m=0,M-1 do
table.insert(sph,tab[n][m]) table.insert(sph,tab[n][m+1])
table.insert(sph,tab[n+1][m+1]) table.insert(sph,tab[n][m])
table.insert(sph,tab[n+1][m]) table.insert(sph,tab[n+1][m+1])
end
end
cols={}
for z=1,#sph,6 do
v=math.random()/8+.7
col=vec4((225+v)/2,(v+1)/2,v/3,1)
for c=1,6 do
table.insert(cols,col)
end
end
moon=mesh()
moon.vertices=sph
moon.colors=cols
end
function draw()
background(40, 40, 50)
perspective(15)
camera(2000,0,0,0,0,0,0,1,0)
rotate(90,1,0,0)
rotate(-30,0,1,0)
ang=(ang+.2)%360
rotate(ang,0,0,1)
moon:draw()
-- Tests
timeChangePixels = timeChangePixels + 1
if timeChangePixels >= 200 then
cols={}
for z=1,#sph,6 do
v=math.random()/8+.7
col=vec4((225+v)/2,(v+1)/2,v/3,1)
for c=1,6 do
table.insert(cols,col)
end
end
moon.colors = cols
timeChangePixels = 0
end
end
When the sun is hidden by the moon…
function setup()
displayMode(FULLSCREEN)
darkish = 0
moon = {}
moon.pos = vec2(WIDTH * (3/4), HEIGHT * (3/4))
moon.state = 1
sunShine = false
sunShineTable = {}
for r = 1, 270 do
table.insert(sunShineTable, 0)
end
-- You can edit this values
speedAction = 1
end
function draw()
background((255-darkish)/2, 255)
strokeWidth(0)
fill(255, 200, 0, 255)
ellipse(WIDTH/2, HEIGHT/2, 350, 350)
stroke(255, 255, 255, 255)
if sunShine then
translate(WIDTH/2, HEIGHT/2)
for r = 1, #sunShineTable do
rotate(360/#sunShineTable)
strokeWidth(5 + math.random(-2, 1))
line(-200 + sunShineTable[r], 0, 200 - sunShineTable[r], 0)
sunShineTable[r] = sunShineTable[r] + math.random(-1, 1)
end
translate(-WIDTH/2, -HEIGHT/2)
elseif moon.pos.x <= WIDTH/2 then
for r = 1, #sunShineTable do
translate(WIDTH/2, HEIGHT/2)
rotate(360/#sunShineTable)
if sunShineTable[r] <= 100 then
strokeWidth(5)
line(-200 + sunShineTable[r], 0, 200 - sunShineTable[r], 0)
end
translate(-WIDTH/2, -HEIGHT/2)
sunShineTable[r] = sunShineTable[r] + 2 * speedAction
end
end
strokeWidth(0)
fill((255-darkish)/2, 255)
ellipse(moon.pos.x, moon.pos.y, 350, 350)
-- In total shine
if moon.pos.x > WIDTH/2-5 and moon.pos.x < WIDTH/2+5 then
sunShine = true
else
sunShine = false
end
-- Lightning Check
if moon.pos.x <= WIDTH/2 then
moon.state = 2
end
if moon.pos.x <= WIDTH/4 then
moon.state = 0
end
if moon.state == 1 then
darkish = darkish + .05 * speedAction
elseif moon.state == 2 then
darkish = darkish - .05 * speedAction
end
moon.pos.x = moon.pos.x - .05 * speedAction
moon.pos.y = moon.pos.y - .0385 * speedAction
end