Mayavi, clip planes

In the program below I try to put a section of the earth (ocean), a tower (of a wind turbine) at origo, and the Sun.
My final goal is to animate the sunset as seen from some hundred meters behind the tower - and with the real curvature of the Earth.

When zooming in the nearest objects seem to disappear too early - as if there was a 'near clip plane' (WebGL term).
In the actual program I have put the Sun too near the Earth because if I put the Sun at its real position (units in meters) I cannot see the objects in the foreground at all.

Is there any way to make it better?
If I am right about the 'near clip plane' is there any way to modify the position of that plane (and eventually also a 'far clip plane')?

Poul Riis
Denmark

import numpy as np
from mayavi.mlab import *
from math import *
from matplotlib.colors import hsv_to_rgb

onemillion=1000000
unit=1000000 # sizes and distances well be in meters if unit is set to one million
rsun=150000*unit
Rsun=700*unit
Rearth=20*unit/pi
dmax=Rearth/100
phimax=atan2(dmax,Rearth)
htower=300/onemillion*unit
rtower=3/onemillion*unit

def cylinder(pos,axis,radius,length):
pi = np.pi
twopi=2*pi
cos = np.cos
sin = np.sin
dphi, dh = pi / 250.0, 0.1
[phi, z] = np.mgrid[0:pi + dphi * 1.5:dphi,
0:length:dh]
ex=[1,0,0]
normaxis=sqrt(axis[0]**2+axis[1]**2+axis[2]**2)
ez=[axis[0]/normaxis,axis[1]/normaxis,axis[2]/normaxis]
ey=[0,-ez[2],ez[1]]
x = pos[0]+radius*(cos(phi)*ex[0]+sin(phi)*ey[0])+z*ez[0]
y = pos[1]+radius*(cos(phi)*ex[1]+sin(phi)*ey[1])+z*ez[1]
z = pos[2]+radius*(cos(phi)*ex[2]+sin(phi)*ey[2])+z*ez[2]
return mesh(x, y, z, colormap="copper")

def calot(pos,axis,radius,deltatheta):
pi = np.pi
twopi=2*pi
cos = np.cos
sin = np.sin
dphi, dtheta = pi / 250.0, deltatheta/250.0
[phi, theta] = np.mgrid[0:twopi + dphi * 1.0:dphi,0:deltatheta:dtheta]
ex=[1,0,0]
normaxis=sqrt(axis[0]**2+axis[1]**2+axis[2]**2)
ez=[axis[0]/normaxis,axis[1]/normaxis,axis[2]/normaxis]
ey=[0,-ez[2],ez[1]]
x = pos[0]+radius*sin(theta)*(cos(phi)*ex[0]+sin(phi)*ey[0])+radius*cos(theta)*ez[0]
y = pos[1]+radius*sin(theta)*(cos(phi)*ex[1]+sin(phi)*ey[1])+radius*cos(theta)*ez[1]
z = pos[2]+radius*sin(theta)*(cos(phi)*ex[2]+sin(phi)*ey[2])+radius*cos(theta)*ez[2]
return mesh(x, y, z,color=(0,0,1))

figure(size=(1200,1000))
cylinder([0,0,0],[0,0,1],rtower,htower)
rgb1=hsv_to_rgb((0.2,0.7,1))
xaxis=quiver3d(0, 0, 0, 1000,0,0, line_width=2, scale_factor=1)
yaxis=quiver3d(0, 0, 0, 0,1000,0, line_width=2, scale_factor=1)
calot([0,0,-6366000/100],[0,0,1],6366000/100,pi/180/2*10)
points3d(-0,-1500000,1000,7000,resolution=256,scale_factor=1,color=(rgb1[0],rgb1[1],rgb1[2]))
hsv_to_rgb((0.2,0.7,1))
view(90, 89, 5000,(0,0,0))