6 Replies Latest reply on Jul 18, 2012 10:32 AM by captain_astronaut

    Light behind objects

    captain_astronaut Level 1

      Howdy,

       

      I was wondering how I could get light to look like it was coming from behind my objects? The closest things I found in my search are several year old and was wondering if CS6 had a new way of doing it? Would the lights also be able to cast shadows in the forground from my objects? Every element is on a different layer in case you were wondering.

      Screen Shot 2012-07-16 at 12.23.41 AM.png

        • 1. Re: Light behind objects
          Mylenium Most Valuable Participant

          You need to make the stuff 3D layers, add a light and a shadow catcher florr and play with the light transmission. And of course you can always fake it with 2D layers and perspective distortion using Corner Pin or similar and blending modes.

           

          Mylenium

          • 2. Re: Light behind objects
            BenjaminMarkus Level 4

            Here's an example of 3D backlighting with 3 solids and 2 lights.

             

            Screen Shot 2012-07-16 at 2.45.52 PM.png

             

            Screen Shot 2012-07-16 at 2.46.07 PM.png

             

            The last white solid is either the background or the floor, but the point is they both have the exact same settings.  In other words, light transmission is turned up.

            • 3. Re: Light behind objects
              captain_astronaut Level 1

              Hmm, I'll have to play with that. Thanks.

              • 4. Re: Light behind objects
                captain_astronaut Level 1

                I think I'm getting closer, but I don't seem to be able to get the shadow to come from behind the object. I can get a shadow on the wall, but not on the floor.

                 

                Screen Shot 2012-07-17 at 8.07.56 PM.png

                Screen Shot 2012-07-17 at 8.09.06 PM.png

                There also appears to be an odd effect with the floor that can change if I move the floor around. For example with my dumpster, the bottom of the dumpster disappears unless I move the floor down. I don't know why, since the floor is the bottom layer. But first I wanna solve the shadow question.

                 

                I really appreciate the help.

                • 5. Re: Light behind objects
                  BenjaminMarkus Level 4

                  Try turning light transmission up for the wall and the ground.  As for your odd effect...  When working with 3D layers the heirarchy no longer acts the way it would when you're working with 2D layers.  It doesn't matter which layer is on top or on the bottom in the timeline.  It only matters where you place the layers in 3D space.  Most likely, the reason why the bottom of the dumpster disappears is because the floor is physically covering it up.  If you set up your monitor for two views, one view your active camera and the other a custom camera, you can move your custom camera around in 3D space to get a better look at exactly how your layers are placed in 3D space.  Hit the c-key several times to get a variety of different tools for moving your custom camera around.  Here's a screenshot of a common setup I use for working in 3D.  I hope this helps and isn't just repeating stuff you already know.

                  Screen Shot 2012-07-18 at 9.29.11 AM.png

                  • 6. Re: Light behind objects
                    captain_astronaut Level 1

                    Trust me, anything helps cuz I know nothin'. I'm a total noob at After Effects. The last time I played with it was 11 years ago. It seems a little easier to navigate now then it did back then.