A ghosted cone.
make object cone 1,10.0
color object 1,rgb(128,128,128)
ghost object on 1
set object 1,1,1,1
color backdrop rgb(96,96,96)
sync on
sync rate 50
do
text 0,0,"Hit [space] to change background"
if spacekey()=1 then color backdrop rgb(rnd(1)*127,rnd(1)*127,rnd(1)*127):wait 100
sync
loop
Doesn't look that bad, does it? All you've got to do from there is rotate it either to come from your character's hand, or to come from the screen (depending on whether it's a 3rd person or 1st person viewpoint.)
If the camera will end up actually inside the cone (like for a 1st person game), change the last '1' of the 'set object' command to '0'. (Otherwise the cone will become invisible when you look inside of it.)
Part of the 'Emergency Response Noob Shooting Team' :: Feel free to add me to MSN, but don't expect any big favours [unless you like VB6]. ... I pwn small creatures.