LUA TIP: Procedural Sphere with uvmap

[shadmar]

-- This will create an inverted sphere, meant for a skydome or similar

 

function Script:CreateSphere(latitudeBands, longitudeBands, radius)

 

local model = Model:Create()

local surface = model:AddSurface()

 

for latNumber=0,latitudeBands,1

do

local theta = latNumber * math.pi / latitudeBands

local sinTheta = math.sin(theta)

local cosTheta = math.cos(theta)

for longNumber = 0,longitudeBands,1

do

local phi = longNumber * 2 * math.pi / longitudeBands;

local sinPhi = math.sin(phi);

local cosPhi = math.cos(phi);

 

local x = cosPhi * sinTheta;

local y = cosTheta;

local z = sinPhi * sinTheta;

 

local u = 1 - (longNumber / longitudeBands);

local v = 1 - (latNumber / latitudeBands);

surface:AddVertex(radius * x, radius * y, radius * z, x, y, z, u, v)

end

end

 

for latNumber = 0,latitudeBands-1,1

do

for longNumber = 0,longitudeBands-1,1

do

local first = (latNumber * (longitudeBands + 1)) + longNumber;

local second = first + longitudeBands + 1;

 

surface:AddTriangle(second,second + 1,first + 1)

surface:AddTriangle(first + 1,first,second)

end

end

model:UpdateAABB(Entity.LocalAABB)

model:UpdateAABB(Entity.GlobalAABB)

return model

end