Fog isn't a volumetric fog like a mist - it's an effect on objects like MonoCoder has already said.
You can make it look a little better by coloring the backdrop the same as the fog.
Are you after this sort of effect:
Set Display mode 800,600,16
Sync On
Sync Rate 60
Set Text Opaque
Create Bitmap 1,640,480
CLS RGB(0,176,0)
Get Image 1,0,0,257,257,1
Set Current Bitmap 0
Delete Bitmap 1
MatWidth=2000: MatHeight=2000: UsedCol=RGB(255,255,255)
Fog On
Fog color UsedCol
fog distance MatHeight*1.4
Backdrop On
Color Backdrop UsedCol
Make Matrix 1,MatWidth,MatHeight,40,40
Prepare Matrix Texture 1,1,1,1
For Nz=40 To 0 Step -1
For Nx=0 To 40
Set Matrix Height 1,Nx,Nz,Rnd(50)+Nz*20
Next Nx
Next Nz
Update Matrix 1
Position Camera 1000,100,100
Point Camera 1000,0,1000
Do
If SpaceKey()=1
If FogShowing=0
FogShowing=1
fogIn(MatHeight*1.4,10)
Else
FogShowing=0
fogOut(MatHeight*1.4,10)
Endif
Endif
Center Text 400,0,"Press Space To Fade Fog In And Out"
Sync
Loop
End
function fogIn(Dist,Delay)
for i=Dist to 150 Step -10
fog distance I
Sync
Wait Delay
next i
endfunction
function fogOut(Dist,Delay)
for i=150 to Dist Step 10
fog distance I
Sync
next i
endfunction
TDK_Man
