Camera Depth of Feild help ??? and Fog question

[andy gee]

H i every body

I need some help regarding Depth of feild in the camera options panel in lightwave 7.5

I have created a set complete with grass trees ect... I have a character standing on a path looking at the camera. Now i want my character to be in focus while further behind him i want to be out of focus. I now that the Depth of Feild option does this But i cant get my head round it !!

I used a range finder on my character and entered the distance in the DOF panel BUT
the F-Stop value i have NO idea.

Can anybody shed some light on this as it should be straight forward !

If anybody can help then that would be great !!

Cheers

Andy Gee !!!

P.S can anybody tell me how to use FOG in a scene ! i want to create some misty spots ?? :confused:

[jeremyhardin]

once your focal distance is set, you might try some lower f-stop values (like 0.1) and tweak from there.

there's a new plug-in that makes it all a lot easier. it has:

opengl guides in all views for fstop and focal length
advanced camera control:
autofocus
fstop slider
zoom slider
and it's an internal process (not post or external), so its:
compatible with volumetrics, saslite, and anything else that lw dof is compatible with.
adds to your existing scene at any point in the workflow

iDof:
http://lwidof.net

for simple fog, hit d for display options and turn on fog circles.
go to your top view and make sure you can see the camera.
click your scene tab at the top, and select volumetrics from the side menu.
change your fog type from none to whatever you like.
change the minimum amount/distance (and watch the circles change around the camera)
change the maximum amount/distance
set the color how you want it.

it's simple, but it works for some situations. hope that helps.

[sannyasi]

Your FStop in conjunction with apature size of the camera controls the distance objects can be from the focal point and still be in focus, (works the same as a real camera so you could find some articles or tutorials for a real cam online)

I made up this quick scene to help you out, it free and won't expire in 10 days like the trial of IDOF. (of couse it wouldn't be as good as IDOF).

This is similar to how I used to setup DOF before I got into compositing, now I use depth passes to do DOF, you could use any compositing app like shake or afterFX, lot quicker that way.

There are three nulls (one locked)
focalDistance, does just that, an expression links the distance in Z to focal distance.

fStop, controls on the -Z axis fStopBuffer to give you a visual range, as well as controls the fStop of the camera.

The distances aren't nearly exact, meaning you can't guage your DOF just on the distance of the nulls, and of course changing your apature will change things dramaticly. But once you have it close its a quick way to animate your DOF, basicly the closer fStop null is to focalDistance null the more blury objects out of that range become. Adujsting the fStop expressions *-.3 to something else will change the range of the actual F-Stop.

Since you always need at least one light in your scene I parented it to the focal Distance and put the color to green, It only affects OpenGL, so it should give you an indication through the camera where the distance is.

As for the fog, if you'll be needing to travel through it you can use hypervoxels, but it is going to kill your render times, you may be able to get away with sprites on particles.
It all depends on the shot.


Hope all that helps and wasn't too much to read, anyway I needed something to do:D