7 Replies Latest reply: May 17, 2014 12:13 PM by treeinthesky RSS

    Walking on water in AE


      I have been brainstorming and experimenting and trying to find ways to composite a green screen shot of a person walking on water.

      I'd like to make it as realistic as possible, with the actor's reflection in the water, as well as water splashes each time his feet take a step.

      Any suggestions?!? This is really a stumper for me!

        • 1. Re: Walking on water in AE
          Rick Gerard MVP

          The trick is in the shooting or spending a bunch of time in post with 3D programs and fluid simulators. NOT EASY


          I'd take some 2X4's make a frame, put a plastic tarp in the frame to hold about an inch of water and shoot away. I've actually done this type of thing a few times in my 40 years of film making.


          Carefully lit and carefully planned that is the way to pull this off as a compositing project instead of a 3D fluid simulation project.


          The reflections are the easy part.

          • 2. Re: Walking on water in AE
            treeinthesky Community Member

            I agree with you about 3D & fluid simulators! I like your 2x4 construction idea, though I'm wondering how I'd get a straight shot on that.

            • 3. Re: Walking on water in AE
              Fuzzy Barsik Community Member
              The reflections are the easy part.

              Well, that rather depends on a level of realism the OP wants to get. Realistic water reflection goes in sync with water surface distortion.

              • 4. Re: Walking on water in AE
                Rick Gerard MVP

                Setting up the camera is easy. I don't know what you mean by a straight shot but here's what you need to do.


                Set up the shot so that the perspective matches the background footage, simple as that. If you shot the background plate then just match the camera position, set up the green screen so that you have green under the water and behind the actor, match the lighting in the background plate and shoot away.


                Then you roto out the frame in post, pull the key, or multiple keys if necessary, color grade the keyed footage, add light wrap, and use distort effects and blend modes to replace the water and make it look real.


                Like I said, this takes some knowledge of lighting and you have to fairly closely match the perspective of the background plate, but once you have the camera positioned correctly, if you shoot with a professional camera to a 422 or 444 color space and 10 bit or better video, you'll have no problem pulling a good key and retaining the water. I've shot a bunch of green screen of folks drinking from plastic bottles and water glasses with SD Digibeta footage and pulled effective keys in AE. Shoot this kind of shot on a consumer camera with AVCHD compression and you are going to be in for a lot of work. I have even shot a sequence where an actor walked on water. It's not that hard if you plan, test, plan some more, test again, then shoot the final shot and composite. All of that work is less work than working with fluid simulations in a 3D app and creating the composite.

                • 5. Re: Walking on water in AE
                  Rick Gerard MVP

                  Distorting the reflection is just a matter of grading the keyed out water reflections and using that layer as a displacement map. EZ as pie if the footage is well shot. If I could figure out how to search this new forum I could point you to a thread on creating a ripple on a pond with a displacement map. If I remember right it even included a project file.

                  • 6. Re: Walking on water in AE
                    Fuzzy Barsik Community Member

                    Rick, I'm dealing with water on almost daily basis (shooting underwater and processing underwater footages), and I've seen not many projects with realistic water simulation so far. I'd appreciate if you could find that thread so that we can check the resulting look.

                    • 7. Re: Walking on water in AE
                      treeinthesky Community Member

                      that's some great info, thanks a lot! you've given me some good things to think about.

                      do you have some of your walking on water work up online somewhere? i'd love to see what you made.