5 Replies Latest reply on Oct 7, 2009 2:27 PM by James Ashburn

    How do you cast shadows on a 2d floor?

    James Ashburn

      Hi I have a shot background with a perspective floor. That I want to add moving video raising out from it with cast shadows. My problem is I can get the effect I want but then can't remove the white floor which is creating the z clip and also casting the shadows on the shot floor.

       

      Is there a simple way to fix this please.

       

      Orginal shot:

       

      Original.jpg

       

      Want to add these images coming out of the shot floor.

      Animated Frames.jpg

       

      Sorry it is probably very simple but just can't get it to work. Any help much appreciated. Thanks

        • 1. Re: How do you cast shadows on a 2d floor?
          Rick Gerard Adobe Community Professional & MVP

          Select all layers that you want to cast and receive shadows along with all lights that you want to cast shadows. Press the "a" key twice quickly.   You will be able to see the options that let you set up shadows. That's all thre is to it.

          • 2. Re: How do you cast shadows on a 2d floor?
            James Ashburn Level 1

            Thanks Rick for your help. I have done that already as you can see from the second image. All layers have shadows but it is removing the white floor layer that I have a problem with. As I want the shadows to fall on the shot floor not the white floor. Hope this makes sense.

             

            Thanks again.

             

            James

            • 3. Re: How do you cast shadows on a 2d floor?
              Mylenium Most Valuable Participant

              You cannot do this directly. Unfortunately AE doe not offer a "Shadow Catcher" material option. You will have to duplicate the comp, replace your otehr items with white solids, combine that with your existing shadow renders and then use belnding modes (Multiply) to superimpose the shadows onto your footage or you unmultiply it to get native transparency...

               

              Mylenium

              1 person found this helpful
              • 4. Re: How do you cast shadows on a 2d floor?
                Rick Gerard Adobe Community Professional & MVP

                It looks like I missed the mark.

                 

                Here's how I'd do it:

                1. Turn all layers 3D
                2. Add a camera
                3. Auto Orient the background layer (your 2D layer) to the camera
                4. Create a white solid about 2X the size of the comp
                5. Make the white solid 3D
                6. Duplicate the white solid
                7. Name one solid y grid, the other z grid
                8. move the anchor point of the y solid to the bottom of the layer
                9. Apply Grid to both solids
                10. Rotate the y solid 90º on the X axis
                11. Duplicate the white solid and remove the grid effect, name it shadow catcher and set the blend mode to multiply
                12. Lock the solids and the background
                13. Select 2 views one active camera the other left
                14. Adjust the position of the camera so that the grid looks like it matches the perspective in the background layer
                15. Add a reference object like a cube made of solids that sits flat on the y grid layer (the floor)
                16. Add a light
                17. Adjust the light so that the shadows match
                18. Turn off the grid layers
                19. Animate...

                 

                Here's a CS4 project that demonstrates the technique.

                I should do a tutorial . . . .

                 

                3dShadow.jpg

                1 person found this helpful
                • 5. Re: How do you cast shadows on a 2d floor?
                  James Ashburn Level 1

                  Thanks so much Rick. Works a treat. Your help was extraordinary. All the best.

                   

                  James