12 Replies Latest reply on Mar 30, 2016 12:56 PM by JSAP

    3d carousel distorts when moving null position.

    JSAP Level 1

      Hi everyone,

       

      I've created a 3d carousel of images to simulate a scrolling wheel of image content.

       

      Screen Shot 2016-03-28 at 11.36.27 AM.png

       

      Everything is set up nicely so that when I rotate the null the carousel rotates as it should.

       

      The problem I am now experiencing is that when I move the carousel to justify it left on the screen it will distort the visual perspective of the carousel. It looks like this:

       

      Screen Shot 2016-03-28 at 11.38.49 AM.png

       

      You'll notice I created a, 'controller' null for the other null object that controls the rotation of the carousel.

       

      I'm trying to have the rotation of the carousel stay square and facing the camera despite where I need to position it on the screen. Any help or tips to better optimize this desired effect is greatly appreciated.

       

      Thank you all kindly in advance.

       

      Best.

        • 1. Re: 3d carousel distorts when moving null position.
          Szalam Adobe Community Professional & MVP

          You could set the null object to auto orient towards the camera.

          • 2. Re: 3d carousel distorts when moving null position.
            JSAP Level 1

            Szalam,

             

            Thanks for your response.

             

            I tried your suggestion and this is the result I am getting:

             

            2016-03-28_1215.png

             

            It forces the squaring of the arrayed objects correctly, however do you notice the skew that has occurred in the array of the objects?

            • 3. Re: 3d carousel distorts when moving null position.
              Rick Gerard Adobe Community Professional & MVP

              There are a few things that concern me. First your circle isn't round. That makes me think you may be working with non square pixels. That's a bad idea. The second is that there is not a camera in the comp so you have no adjustment of where the camera is looking. The third is that if the camera is pointed directly at the center of the composition which is what is going to happen when you have not added a camera and you move a 3D object to the left the foreground of the object is going to be farther to the left than the background of that 3D object. That's how perspective works. The only option would be to rotate the 3D object on the Y axis to reorient it in relation to the camera. What you are seeing is perfectly normal. It's what would happen in real life. The farther the camera is moved from the carousel the more this perspective is reduced. I'm not sure what you are trying to achieve visually but auto orienting the null to the camera is going to foul things up when you try and rotate the carousel and the oval path is also going to give you some visual problems.

               

              Edit: looks like you noticed that problem. You are just not understanding perspective and camera position. It seems that what you want is an orthographic projection of the carousel and AE can't do that. You can get close by selecting a very long lens and moving the camera way back but there will always be some perspective in an AE camera.

              • 4. Re: 3d carousel distorts when moving null position.
                JSAP Level 1

                Thanks Rick,

                 

                Great feedback.

                 

                I'm trying to achieve a rotating carousel that I can position to the left hand side of the screen to compliment some footage I'm placing to the right.

                 

                In addressing your first point about the pixels not being square. Are you suggesting that each image is square for a proportional array around the circle?

                 

                How would you suggest positioning the carousel so that I can justify it's placement left but have no visual perspective distortion?

                 

                Thank you

                • 5. Re: 3d carousel distorts when moving null position.
                  Szalam Adobe Community Professional & MVP

                  Precomp it when it's in the center. Move the precomp to the side.

                  • 6. Re: 3d carousel distorts when moving null position.
                    Dave LaRonde Level 6

                    JSAP wrote:

                    In addressing your first point about the pixels not being square. Are you suggesting that each image is square for a proportional array around the circle?

                    No, Rick's suggesting that your COMPOSITION SETTINGS aren't set for square pixels.  Open the comp settings -- you'll probably discover the Pixel Aspect Ratio is NOT 1.0, or square.  You can get things straightened around, but you're probably better off just by starting over with a new comp.  With square pixels.  I'll guess that you need 1280x720.... or 1920x1080.  And don't forget to put in the proper frame rate.

                    • 7. Re: 3d carousel distorts when moving null position.
                      JSAP Level 1

                      Yahtzee!

                       

                      I was able to figure that much out, and pretty much solve what I was asking for. Thank you both kindly for the advice.

                       

                      I do have another issue that I am hoping that you may be able to lend insight or offer your creative suggestion, and that is masking... How do I know mask the carousel so as when it rotates you see the front facing object but you can't see the far off object behind it rotating as well?

                       

                      Thanks in advance.

                      • 8. Re: 3d carousel distorts when moving null position.
                        JSAP Level 1

                        Dave thank you kindly, sir.

                         

                        I did indeed go back to verify and that was the case. I've since successfully created the carousel and positioned it where I would like with no visual distortion perceived. 

                         

                        Stuck in this latest episode however, wrangling with different masking techniques to reveal just forward facing front part of the carousel and hide the back part of it. -Any ideas, or suggestions for this?

                        • 9. Re: 3d carousel distorts when moving null position.
                          Szalam Adobe Community Professional & MVP

                          There are a number of ways to do this. One would be to use CC Cylinder on a really, really long precomp containing your images. Then you'd rotate the cylinder to show the pictures. You could choose to just render the outside of the cylinder. If you're doing it as 3d layers, you could use expressions so that opacity is 0 when it's facing away from the camera or make the opacity be 0 when the cylinder is at a certain spin angle (this would need to be offset per layer by its index, but that's probably more complicated than you would like.

                          You don't have that many images, you might just trim the layer in and out points...

                          • 10. Re: 3d carousel distorts when moving null position.
                            Dave LaRonde Level 6

                            You can't make the backward-facing pictures transparent, but you CAN put a back on them.  Do it in another picture-sized comp.  Add the picture and a comp-sized solid.  Make both 3D.  Move the picture -1 pixel in z-space.  Move the solid +1 pixel in z-space.  Replace your current pictures with this comp, turn on collapse transformations for these comps, and you should be good to go.

                            • 11. Re: 3d carousel distorts when moving null position.
                              Rick Gerard Adobe Community Professional & MVP

                              There is also an expression (which I can't rewrite from my head as I'm replying on my phone) That hides a layer when it is facing away from the camera. Check Dan Ebbberts motionscript.com site for the expression.


                              Apply to opacity:


                              if (toCompVec([0, 0, 1])[2] > 0 ) value else 0

                               

                              Dan Ebberts's Expressioneering Design Guide For an explanation of how this works.

                              • 12. Re: 3d carousel distorts when moving null position.
                                JSAP Level 1

                                Thanks again everyone for the help.

                                 

                                The designers have provided me this long string of vehicles and I'm approaching this task cautiously based on what I've learned so far about setting up this carousel.

                                 

                                Any tips here for properly setting this up either using the null parent rotation method or cc cylinder for best optimization would be greatly appreciated.

                                 

                                Screen Shot 2016-03-30 at 3.49.55 PM.png