I'm no trying to twist your arm. I think if you would just try it you'll notice what I’m getting at. Maybe this little demo will illustrate the affect of disabling zwrite better. Here I’m using a 10x10x10 skybox and a plane 1000x1000. The camera height is set at 30. Without disabling the zwrite on the skybox the plane would not be visible. Try it, media attached.
load image "sky_B.png", 1
load image "sky_D.png", 2
load image "sky_F.png", 3
load image "sky_L.png", 4
load image "sky_R.png", 5
load image "sky_U.png", 6
load image "grass.png", 7
sync on
sync rate 60
backdrop on
autocam off
position camera 0, 30, 0
make object plane 1, 10, 10, 1
make mesh from object 1, 1
offset limb 1, 0, 0, 0, 5
texture limb 1, 0, 1
add limb 1, 1, 1
rotate limb 1, 1, 0, 90, 0
offset limb 1, 1, 5, 0, 0
texture limb 1, 1, 5
add limb 1, 2, 1
rotate limb 1, 2, 0, -90, 0
offset limb 1, 2, -5, 0, 0
texture limb 1, 2, 4
add limb 1, 3, 1
rotate limb 1, 3, -90, 0, 0
offset limb 1, 3, 0, 5, 0
texture limb 1, 3, 6
add limb 1, 4, 1
rotate limb 1, 4, 90, 0, 0
offset limb 1, 4, 0, -5, 0
texture limb 1, 4, 2
add limb 1, 5, 1
rotate limb 1, 5, 0, 180, 0
offset limb 1, 5, 0, 0, -5
texture limb 1, 5, 3
set object collision off 1
set object texture 1, 2, 0
set object light 1, 0
set object cull 1, 1
set object fog 1, 0
disable object zwrite 1
make object 2, 1, 7
delete mesh 1
rotate object 2, 90, 0, 0
scale object 2, 10000, 10000, 10000
scale object texture 2, 5, 5
set object cull 2, 1
do
set cursor 0, 0
print "FPS: ";screen fps()
control camera using arrowkeys 0, 1, 2
position object 1, camera position x(), camera position y(), camera position z()
sync
loop
