# Got unexpected results from perlin noise. Wondering what it is doing?

I was just messing around with perlin noise and got this. Wondering if anyone knows what it is or has seen it before.

Here is the code(LUA with love2d engine):

function love.load()
love.window.setMode( 1920, 1080, {fullscreen=false})
--Assuming you called the module perlin.lua
newperlin = require("perlin2")
--newperlin is a function that generates Perlin noise objects:

myperlin = newperlin()
--333 is seed
myperlin = newperlin(333)
mapHeight = 400
mapWidth = 400

--then, to create noise:
scale = 0.007
map = {}
for x = 0, mapWidth - 1 do
map[x] = {}
for y = 0, mapHeight - 1 do
map[x][y] = 0
map[x][y] = --[[map[x][y] + --]](myperlin:noise(x * scale, y
* scale) + 1) / 2.0 * 255.0
--The following lines change it from a cloud to a weird image
smin=0; smax=255
map[x][y] =  math.floor(( map[x][y] - (-0.5) ) * 255 / ( 0.5
- (-0.5) ) + 0)
end
end
end
function love.draw()
for x = 0, mapWidth - 1 do
for y = 0, mapHeight - 1 do
love.graphics.setColor(map[x][y], map[x][y], map[x][y], 255)
love.graphics.point(x,y)
end
end
end

function love.update()

end

function love.keyreleased(key)
if key == "escape" then
love.event.quit()
end
end


and here is perlin.lua:

## 1 Answer

You are going outside the 0..255 range. That's why you see these color bands, since you are goint the whole range of values between 0..255 for every integer.

You are multiplying by 255 twice. This has nothing to do with perlin noise.