15 Replies Latest reply on Jan 1, 2009 12:34 PM by (Fran_Baker)

    Simulating Fog in AF CS4

      I've just downloaded the trial version of After Effects CS4 with a view to buying the Production suite soon, (I hope).

      I'm at University and have used After Effects before and the tutor once showed me how to make fog using Generate/Simulation (I think) - but this was on CS2 I think.

      The University say they cannot afford to Upgrade to CS4 at present, which is why I'm thinking to buy for myself.

      HOWEVER! I have an animation project, in After Effects, that I need to finish in the next few days.
      I'm away from Uni until the hand-in deadline.
      And I can't remember how to do fog.
      Anyway CS4 might have a better way than CS2 (or whatever the Uni had)

      I've found Generate and Simulation but after that I've forgotten the procedure, or CS4 is different, so I'm currently looking at "Particle Playground".
      But the particles are red, despite my making the solid layer (on which I'm using "Particle Playground") a nice darkish grey.

      I'm also having problems with gravity and force???

      Plus it needs to be much fuzzier, and not red...

      Here's a screen shot showing what I have so far:

      Here's what I'm aiming for, but animated:

      (Made in PhotoShop)


        • 1. Re: Simulating Fog in AF CS4
          Mylenium Most Valuable Participant
          You links are identical, so I can't really see what you are after, but most likely you are referring to smoke rather than fog. For what you want, you will have to work with the property maps, e.g. a simple gradient to fade out the opacity as your particles rise.... And color can be controlled directly or using the same procedure.

          • 2. Re: Simulating Fog in AF CS4
            Level 1
            Sorry, dunno why the links turned up like that, try this:

            For what I've got,

            and this:


            for what I'm aiming for.

            I never heard of "Property Maps" before, where is that in the Particle Playground thingie?
            • 3. Re: Simulating Fog in AF CS4
              Andrew Yoole MVP & Adobe Community Professional
              The look in your second link may be more easily achieved using Fractal Noise, using a foreground and a background layer/iteration. Perhaps even a combination of both particles and Fractal Noise.
              • 4. Re: Simulating Fog in AF CS4
                Level 1
                I've used a sort of noise on the solid layer, - "Turbulent Noise" but I used this as well as the particles, since alone the noise is just a flat layer and it's not possible to see through the fog in patches, as you would with particles.


                Unfortunately I can't remember where to change the particles to make them circular and soft edged (fuzzy) rather than rectangular and hard edged as they are at present.

                Like this:

                Does anyone know how to correct this?

                Oh and here's the same scene with the Turbulent Noise added:


                See? You can't disguise the rectangles.

                • 5. Re: Simulating Fog in AF CS4
                  Andrew Yoole MVP & Adobe Community Professional
                  Have you tried Fractal Noise applied to a solid? Change it to a transfer mode like Screen to provide transparency.
                  • 6. Re: Simulating Fog in AF CS4
                    Level 1
                    Yeah, I tried that, I'm afraid it looks hopeless.

                    But I'm sure it was in "Simulation/ParticleWorld" in the version of AE at uni, but CS4 doesn't have that, it only has "Particle Playground". and I can't figure out how to make the particles in there circular and fuzzy at the edges.
                    • 7. Re: Simulating Fog in AF CS4
                      Andrew Yoole MVP & Adobe Community Professional
                      CC Particle World is definitely provided with AE CS4, but it isn't activated whilst running in Trial Mode. You will need to either use a purchased installation of CS4, or download the Demo version of CycoreFX HD. Note that the Cycore Demo will have a big X through the picture until you pay for the plugins, however.

                      • 8. Re: Simulating Fog in AF CS4
                        Level 1
                        Oh hell.

                        A big X throughout my work is not going to be acceptable to the tutor/s/external examiners.

                        And as I have no money until at least halfway through January (and thus well after the hand-in day) - I'm up sh!t creek without a paddle.

                        By the way, if CC Particle World is available with AE CS4 - why can't I see it anywhere?

                        According to the Adobe site this demo is supposed to be fully functioning.
                        • 9. Re: Simulating Fog in AF CS4
                          Todd_Kopriva Level 8
                          Why are you trying to simulate fog? It's very often faster, easier, and more realistic to shoot fog or steam (or get a cheap stock footage clip of fog) and use that. Even if you need to have it flow in specific ways, you can use Distort effects and time-remapping to alter the spatial and temporal characteristics of the real fog clip. If you need to see through the dark areas of the clip, just use blending modes or perhaps use a copy of the fog layer as a luma matte.

                          I just did a Community Help search for 'fog', and I see that a link to the "Fog, smoke, clouds, and such" section of After Effects Help is one of the results. Maybe that document will help.

                          > By the way, if CC Particle World is available with
                          > AE CS4 - why can't I see it anywhere?
                          > According to the Adobe site this demo is supposed to be
                          > fully functioning.

                          from the "Installation, activation, and registration" of After Effects Help:

                          " Important: The free trial version of Adobe After Effects software does not include some features that depend upon software licensed from parties other than Adobe. For example, mocha for After Effects, some effect plug-ins, and some codecs for encoding MPEG formats are available only with the full version of Adobe After Effects software."
                          • 10. Re: Simulating Fog in AF CS4
                            Level 1
                            Unfortunately for the purposes of this particular animation I am only using live footage at the end - with no fog requirement in that section.

                            This part of the animation has to look unreal, as it's fantasy - it must look very different to the live footage at the end when reality steps in, so this section is thus done inside AE with a drawn character not a real bloke, the buildings and ground are made up from Photographic images set into position.

                            The fog is a vital part of the story. And I need it to be pretty thick but controllable so I can have my character visible now and then through gaps in the fog.

                            I too looked at community help and found I think that same "Fog, smoke, clouds, and such" they keep talking about Mark Christiansen - well I also looked at that before asking in the forum, looked in lots of places in fact, and the Mark C site didn't help, it seemed to be rather vague with everything I saw on that site in fact, very frustrating.

                            Ah... I may have done that Mark C site an injustice, I didn't initially realise that there were 6 pages...

                            I'll go take a closer look at the correct page.
                            • 11. Re: Simulating Fog in AF CS4
                              Level 1
                              Your link to the sample you want to emulate is broken. I did see a fog example in your Photobucket gallery that gives me some ideas.

                              First of all, you'll need to separate foreground and background elements then put a fog layer between them and add another fog layer on top. IOW

                              Fog FG
                              Fog MG

                              I'd use fractal noise to generate the fog. I'd also use a mask to shape the fog on the top layer.

                              If you're using the trial version of AE the CC filters are not included because of licensing agreements. That's why you are not seeing them.

                              There are several tutorials out there are clouds. This one from Creative Cow will give you a primmer on Fractal Noise and layers and should get you started.

                              There are also a bunch of Fractal Noise tutorials at Çreative Cow that will help you get a handle on that effect.
                              • 12. Re: Simulating Fog in AF CS4
                                Level 1
                                Licensing agreements eh? makes sense.

                                I've ordered the Production Suite on an education license, now I'm just awaiting confirmation that my student ID is accepted.

                                I can't afford it otherwise.

                                I've had a go at the cotton wool ball fog tutorial, and even though it's just a couple of layers so far, I think it has potential, what do you think?

                                Here's what I've got so far:


                                I'm going to photograph a few more varieties of cotton wool fog tomorrow - for more layers.
                                • 13. Re: Simulating Fog in AF CS4
                                  Level 1
                                  The link is broken?

                                  I just tried it again and it works fine for me,

                                  This is the link for what I'm trying to get:


                                  I think the mesh warp on images of cotton wool might just work, but thanks to a very generous birthday present I've now ordered the Production Suite - it may or may not arrive in time for me to use it for this project...

                                  Knowing my sort of luck, it won't.

                                  So I think cotton wool fog is going to be the best I can manage for now.
                                  • 14. Re: Simulating Fog in AF CS4
                                    Ko Maruyama User Group Manager
                                    Turbulent Distortion or some very fine displacement map reference might help you to make some of the smaller parts of the fog move
                                    • 15. Re: Simulating Fog in AF CS4
                                      Level 1
                                      Well the tutorial talks about using "Liquify, for finer distortion than Mesh warp can give you so I thought I'd try that.

                                      Turbulent distortion might be a bit rough, although I'll take a look at it.

                                      I'm not sure what you mean by "very fine displacement map reference".

                                      Where's that?