5 Replies Latest reply on Jan 8, 2016 8:25 AM by mbirame

    Newbie question: Lining up C4D model correctly in After Effects

    mbirame Level 1

      H folks,

      I have a prop (in the real world) that we do projection mapping on to.  I have that prop modeled in Cinema 4D.  I also have a 1080P .jpeg that I created by projecting a white 1080p canvas onto the prop and tracing the outline of the prop. 

       

      Here is the outline that shows exactly how the projector is hitting the prop:

       

      Full Prop Map.jpg

       

      and here is a screenshot of the prop in C4D:

      Screen Shot 2016-01-07 at 7.52.45 PM.png

       

      So what I'm trying to figure out is how best to line up that prop in After Effects so that it is exactly where it needs to be so that I can do my 3D modeling effects in C4D and then render out of After Effects for the projector. 

       

      So far, I have tried creating a new camera in C4D and then just trying to precisely rotating and moving the camera around to get things to line up, but after about 30 minutes of fiddling with it I still couldn't get it exactly right so I figured there must be a better way....Any help would be appreciated!

        • 1. Re: Newbie question: Lining up C4D model correctly in After Effects
          Mylenium Most Valuable Participant

          It's not really relevant, is it? All you need in AE are the faces as viewed from the projectors lens, possibly color coded or as separate object buffers per face. If you don't know the specs, projecting a grid onto the real thing and taking photos can tell you a lot. Otherwise the camera matcher/ 3D tracker in C4D can do a lot for you...

           

          Mylenium

          • 2. Re: Newbie question: Lining up C4D model correctly in After Effects
            mbirame Level 1

            All you need in AE are the faces as viewed from the projectors lens, possibly color coded or as separate object buffers per face.

            Can you clarify what that means?  Are you saying to recreate the prop only in after effects?

            • 3. Re: Newbie question: Lining up C4D model correctly in After Effects
              Mylenium Most Valuable Participant

              You are overthinking/ overcomplicating this. There is no need whatsoever to actually have any 3D unless you plan something to do with it that you are not telling us. In the end, all your projector will do is cast its light on a bunch of triangles. It doesn't even know that they are stacked in depth. That being the case, all you need is the actual triangle areas as distorted by the projector lens and of course with respect to their own inclination on your "peaks". Everything else is unnecessary since your projector will use a bog standard video file one way or the other. Of course an easy way would be mimicking this in a 3D program and taking a snapshot by ways of using a virtual camera that matches the properties of the actual projector lens, but a photo tweaked in PS will do just as well. You only need reference, not actual geometry. The rest can easily be figured out from your plans such as where the projector is in relation to the surface.

               

              Mylenium

              • 4. Re: Newbie question: Lining up C4D model correctly in After Effects
                mbirame Level 1

                There is no need whatsoever to actually have any 3D unless you plan something to do with it that you are not telling us.

                Like I said in the first post:

                " so that I can do my 3D modeling effects in C4D"

                 

                They will not be empty tirangles sitting there, they will be exploded, deformed, etc, etc in C4D and rendered in After Effects.

                • 5. Re: Newbie question: Lining up C4D model correctly in After Effects
                  mbirame Level 1

                  What I would imagine a really easy way would be if I could set four corner points on the prop in C4D and then within After Effects grab those points and line them up to the image?