fog on ground

[Yussef Cole]

If you have a particle system, obviously fog is going to be one of their presets. Like Trapcode particular for example would have great fog – and then you can use the inverse mask of your character for an obscuration layer (so that the fog only fills up the space he’s supposed to take up).

If you don’t, try fractal noise with some creative masking and blurring. Once again you can use an inverse mask so that only the character is cloudy and then have the ‘fog’/fractal noise layer by slowly revealed by an animated mask. If done right I think that would look pretty good, if not entirely 3 dimensionally photorealistic.

[Scott G]

i just made some fog for use over water, but it’s essentially the same thing. my screen was pretty much black, you couldn’t even really tell it was water.

anyway, i used a combination of
a) fractal noise
b) smoke / steam that i filmed then comped in
c) trapcode particular.

A-
the fractal noise gave me “banks” of fog. i made 4-5 comps with different types of fractal noise. i think from memory i used
1) fractal type: basic / noise type: linear / contrast 220 / brightness -15
2) fractal type: dynamic twist / noise type: spline / contrast 220 / brightness -15
3) fractal type: basic / noise type: linear / contrast 200 / brightness -15
4) fractal type: threads / noise type: spline / contrast 120 / brightness -15

different types of noise give the appearance of depth when you layer them. the dynamic twist gives a swirly movement, the basic noise gives patchiness.
try scaling these at different sizes to aid the appearance of depth.

i also played with digieffects delerium fog factory, but only used that in one layer. the near-far fade you can do with this looks nicer than a simple soft mask.

B-
film steam or smoke over black, then comp. it doesn’t have to be pure black, as to make it look like fog instead of smoke i darkened it up and blurred the heck out of it, so no need to be precious when filming.
some footage items i used were stock, and these were actually invaluable as i couldn’t create a similar effect with home made smoke or steam. eg, dry ice behaves much differently to smoke or steam, and obviously i can’t film that myself. that was only one layer in 7 or 8 though, so you can do without it.

C-
using the “smoke” preset of trapcode particular, i modified the properties to get it wafting in the right direction with the right patchiness and turbulence. i could write entire paragraphs about that, but i won’t, you’ll have to figure it out, and every case is different. after half an hour i had several layers of this i could place where needed, for slow wafts, small pufts, or litte displaces.

FINALLY
it helps if you have a subject on a transparent background. whether it’s created this way, or you need to render separate passes or even rotoscope, it helps give the illusion of depth. put some layers behind the character, and some layers over it.

if you want to get really tricky you can add turbulent displaces to some of these layers, or isolate the turbulent displace with a masked adjustment layer.

all this was REALLY render intensive. 6hrs on a g5 for a 30second comp. sheesh! but since i don’t have 3d skills or an inferno, i’ve gotta make do.
hope that helps!

regards,
scott.

[Scott G]

trapcode doesn’t have a fog preset that i could see, i had to modify te smoke preset and use layers. does anyone have any trapcode presets they’re willing to share? 🙂
i’d put my foggy one up, but it’s not really fog, just puffs that i layered over other things. i didn’t try to create a flowing fog “bank” with trapcode. has anyone? do you think it would work?

[Wim Roegels]

I just installed the demo of trapcodes particular … looks good … not that cheap also … anyway … if there is a way to exchange presets with the demo we can do so … sounds goog.

I do my very best … 😉

[Wim Roegels]

Thanks for your detailed answer … I will try and give you feedback.

I’ll be back …