6 Replies Latest reply on Oct 12, 2014 7:43 AM by JJMack

    Specific need: to generate a cylindrical projection NOT from a sphere, but from a flat image

    JoeTalker

      Specific need: to generate a cylindrical projection NOT from a sphere, but from a flat image, like a person's face, etc., such that the cylindrical projection can be used to wrap a sphere (via other software such as the DX I use), where the face could be positioned arbitrarily at the equator (where a cylindrical projection image created FROM a sphere appears most normal), a pole (where a cylindrical projection image created FROM a sphere appears most stretched out), or anywhere else on the resultant sphere's surface. This would allow creation of a, say, a cylindrical projection of a sphere that represents a numbered billiard ball from a flat representation of the number design. Is there an Adobe or Photoshop product that will provide this? Thanks for any help!

        • 1. Re: Specific need: to generate a cylindrical projection NOT from a sphere, but from a flat image
          JJMack Most Valuable Participant

          What version of Photoshop do you use newer Extended version 3D feature has a cylinder mesh preset.

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          [ JJMack ]

          • 2. Re: Specific need: to generate a cylindrical projection NOT from a sphere, but from a flat image
            Noel Carboni Level 8

            Not sure I follow the connections between spheres and cylinders you're describing...  Perhaps if you describe a little more about your actual application it would become more clear.

             

            Or maybe you don't need to.  It sounds like you just want to set the material of a sphere surface to a particular file.  That's pretty easy to do directly.  One way is to just open the image you want and choose as follows:

             

            Extrude.png

             

             

            SphericalProjection.png

             

            -Noel

            • 3. Re: Specific need: to generate a cylindrical projection NOT from a sphere, but from a flat image
              JoeTalker Level 1

              Thanks, Noel. Here's the crux: the image sphincters at the poles, natch. I've been looking for an algorithm or feature in a graphics app that would assume that the flat image of joetalker's entry would be spread proportionately at the poles so that the size of print would be uniform (or the shape of face photo, etc).

               

              Using such a feature would dictate that type, lets say, would be distributed on the flat image something like this in order not to lose too much at the edges (where the sphere mesh meets at 0-longitude), and sphincters as latitude approaches the poles:

              ++++++++Hello+++++++++

              +++++How are you &+++++

              ++What can I do for you+++

              +++++How are you &+++++

              ++++++++Hello+++++++++

               

              Yes, over-simplified. Here with a photo, where the original photo is "X" signs, and the empty space is "+" signs, along with the desired created cylindrical projection ready for a sphere mesh:

               

              Example 1 at equator:

              original:

              ++++++++++++++++++++++++

              ++++++++++++++++++++++++

              ++++++++++XXXXX++++++++++

              +++++++++XXXXX++++++++++

              +++++++++++XXXX+++++++++

              ++++++++++XXX++++++++++

              +++++++++++++++++++++++++

              ++++++++++++++++++++++++

               

              created cylindrcal projection:

              ++++++++++++++++++++++++

              ++++++++++++++++++++++++

              ++++++++XXXXXXXXX++++++++

              +++++++++XXXXX++++++++++

              +++++++++XXXXXXXX+++++++

              +++++++XXXXXXXXX+++++++

              +++++++++++++++++++++++++

              +++++++++++++++++++++++

              -very similar, with a widening at top and bottom of "photo", right?

               

              Example 2 at poles:

              original:

              +++++++++++XXXX+++++++++    (bottom of photo)

              ++++++++++XXX++++++++++

              +++++++++++++++++++++++++

              +++++++++++++++++++++++++

              ++++++++++++++++++++++++

              ++++++++++++++++++++++++

              ++++++++++XXXXX++++++++++   (top of photo)

              +++++++++XXXXX++++++++++

               

              created cylindrcal projection:

              +++XXXXXXXXXXXXXXXXXXXX+++

              ++++++XXXXXXXXXXXXX++++++

              +++++++++++++++++++++++++

              +++++++++++++++++++++++++

              ++++++++++++++++++++++++

              ++++++++++++++++++++++++

              +++++XXXXXXXXXXXXXXX++++++

              ++XXXXXXXXXXXXXXXXXXXXXX+++

              -now with an even more widening toward the poles to compensate for the pole sphinctering.

               

              If starting with a true globe already spatially correct, creating a cylindrical projection is commonplace. I'm attempting to find an app that will create a cylindrical projection-like graphic ready for a sphere mesh from a flat photo or graphic. The above example would place the photo in correct proportion over the pole of the sphere, discarding information at the ever decreasing edges as the image projects to the poles.

               

              Hope this is clear, and thanks again!

               

              -Johnny

              • 4. Re: Specific need: to generate a cylindrical projection NOT from a sphere, but from a flat image
                JoeTalker Level 1

                Thanks, JJ! Please refer to my answer to Noel below for a text-based graphic. Referring to your spinning globe, please imagine the lady's image projected to a cylindrical projection that would distort her image such that her correct proportion would maintain over the poles of the sphere. This would require the user to pay attention to spacing only to the extent of not losing information at the decreasing edges of the image as the projection widens the image toward the poles to avoid sphinctering.

                 

                I am actually shopping for a graphics application that will accomplish this.

                 

                Thanks again!

                 

                -Johnny

                • 5. Re: Specific need: to generate a cylindrical projection NOT from a sphere, but from a flat image
                  Mylenium Most Valuable Participant

                  You simply cannot defeat the math. At best you could use an alternate projection source as the corrective element and then use a flat frontal projection, then use the sphere's UVs to compensate for the sideway skew, but PS doesn't support any such advanced projection and baking techniques. That being so, you will have to apply the inverse of any distortion caused by projecting the texture with whatever method in 2D. Still, even then the image's pixels will converge at the pole and the resulting mapping not  a true representation of the initial image in a mathematical sense.

                   

                  Mylenium

                  • 6. Re: Specific need: to generate a cylindrical projection NOT from a sphere, but from a flat image
                    JJMack Most Valuable Participant

                    https://www.google.com/search?sourceid=chrome-psyapi2&rlz=1C1CHFX_enUS546US546&ion=1&espv= 2&ie=UTF-8&q=Create%203D%20Fac…

                    Humans do not all have the same shaped heads and none have sphere or cylindrical shape heads IMO what you are trying to do will not work. You need a 3d modeling Application or at least a head 3d model you can use in Photoshop and a 360 flat image of the head. to fit the surface areas. Get a 3d camera scaner and 3d application.

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