数学图形(1.1) 圆,椭圆

圆

vertices = 360
w = from 0 to (2*PI)
r = 10.0
x = r*sin(w)
y = r*cos(w)

圆面,面上有纹理坐标,有顶点色

vertices = D1:360 D2:100
u = from 0 to (2*PI) D1
v = from 0 to 10 D2

x = sin(u)
y = cos(u)

r = (x+1)/2
g = (y+1)/2
b = v/10

x = v*x
y = v*y

椭圆

vertices = 1000
r = 10.0
e = 0.75
t = from 0 to (2*PI)
p = r/(1.0 - e*cos(t))
x = p*sin(t)
y = p*cos(t)

随机生成的椭圆

vertices = 360
w = from 0 to (2*PI)
a = rand2(1, 20)
b = rand2(1, 20)
x = a*sin(w)
y = b*cos(w)

 使用圆内旋轮线原理生成的椭圆

vertices = 12000
a = 10
r = 5
d = rand2(0.5, 10)
t = from 0 to (2*PI)
x = (a - r)*cos(t) + d*cos((a/r - 1)*t)
y = (a - r)*sin(t) - d*sin((a/r - 1)*t)

椭圆面

vertices = D1:360 D2:100

u = from 0 to (2*PI) D1
v = from 0.01 to 3 D2

r = 10

x = r*v*sin(u)
y = r*cos(u)