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  • Casting shadow from 3d object

    I need some help, my brain just locks up on this one but it seems their should be a way.

    I need to cast a backlit shadow (I know, it looks hokey but that's what the client wants) from the massage table into the foreground.
    The attached JPEG has a flipped and rotated version on it to illustrate my problem. There is a layered TIF version here...
    http://www.alphabirds.com/RTP/Statio...__DSC_2216.tif

    How do I keep the shadow attached to all four feet while stretching it into the foreground? I cannot figure this out without perpetrating all kinds of weird, marginally repeatable manipulations... I have to do 20 of these with different tables and bases.

    I would truly appreciate any help anyone could offer.

    Ps. I haven't been around lately, we've recently moved our studio and have been pretty occupied getting everything in order. We don't have a storefront anymore and the restoration business is falling off. It really pays to have a streetfront window where people can look at examples and before/after restorations.

    Thanks,
    Chip
    Attached Files

  • #2
    hello Chip,

    While I haven't tried this myself, it seems that this would be accomplished by:

    Selecting the object and fill it with foreground (black) color

    Flip the now selected "shadow" upside down with transform, and move it below the horizon /level of the legs (visualize splitting the page in two and the shadow as a reflection). Align four shadow "legs" with the legs of the object

    Switch to transform and perspective, and then draw or stretch the shadow to size, shape and preference

    Blur / dodge or mask parts of the shadow to generate a fade or weakening of the shadow as it moves further outward.

    I hope this is helpful to you in visualizing another possible way of doing it.

    Sean

    Comment


    • #3
      Originally posted by Sean2
      Align four shadow "legs" with the legs of the object
      Sean
      Yep, if I'm reading you right, you're thinking the same thing I thought. You can align the legs but you can't join the shadow to the table legs at all four feet. The thumbnail illustrates the problem. When you flip the filled outline (shadow), the feet which were furthest from the foreground (the back feet) become the closest. They (the shadow feet) need to be stretched quite a bit without moving the front feet from their point of contact.

      It's really a 3d problem that has to be solved in 2d. I've tried the liquify filter but don't know enough about it to make geometrically clean distortions. What I think I need is a way to anchor the shadow on a line between the front feet where they contact the shadow and stretch everything else back perpendicular to it.

      Thanks for responding.

      Chip

      Comment


      • #4
        I see what you mean. Perspective, skew and distort don't enable the flexibility that one needs to conect the shadow legs to the object.

        I thought about masking, but you run into the same issues. i also tried just using the table and legs, sans the recliner, but that didn't work well either. Can you:

        bisect the shadow you have (along the length of the recliner) and then attach half to the back legs, and then paste the same element to the front legs and draw in connecting or perspective (3D) lines?

        Just trying to think of options.

        sean

        Comment


        • #5
          That's a good idea, I tried some similar things but it ends up being too much manipulation for 20 images.

          Since my last post I've gotten a little further by converting a selection of the shadow to a path and selecting all the points except the feet and transforming that but it's still not right. The path transformation is less flexible and several points need converting to anchors... but it seems to be the right direction unless someone out ther has a better way.

          Doesn't it just seem like this is something lots of people would have done? I expected to find out more with an internet search but I found nothing that addresses actual 3d, just simulated 3d.

          Thanks again,

          Chip

          Comment


          • #6
            This problem may be resolved by the new feature in CS2, but can't think of a way of doing this at present,

            Comment


            • #7
              Chip,

              I have been playing with your shadow image all afternoon and have run into the same issues. I suppose a re-shoot is not in order? If it were, the photographer could shoot one image with a backlight casting a real shadow and then take another shot of the table and then marry the two images in PS. Not a satisfactory solution, I'm sure.

              I have been thinking also, that the lower shelf and the bottom of the image would cast a more solid shadow that just the selected outline of the table. The shadow directly in front of the table would be solid. Maybe their is a solution in that. Does that make sense?

              K

              Comment


              • #8
                Eye Candy

                Hi Chip,

                I dinked around with this in Photoshop for a while but was unable to get the shadow that you created to do what I wanted through the different transform operations.

                I selected the table and used the Eye Candy 4000 Shadow Lab filter to get this loose shadow and was still left feeling like I did not have the right tools to achieve a nice shadow. As you can see the image still needs a lot of cleaning up. However it did yield better results than the transformation tools in Photoshop. You can review Eye Candy filters at http://www.alienskin.com/

                Good luck,
                El
                Attached Files
                Last edited by Eleanor; 04-19-2005, 08:55 PM.

                Comment


                • #9
                  While I'm sure you can get acceptable results with just Photoshop, I would prefer a 3d program.

                  http://forms.caligari.com/forms/ts3all_free.html

                  A handful of boxes, some meta objects for the pillows, and a plane for the shadow to land on.

                  Comment


                  • #10
                    I found no easy solution to this problem, but realized very early on that using the original resulted in problems with the shadow's perspective, and no amount of free transform would correct it. Instead, using a separate layer for each component, I used the poly lasso to create four leg shadows at the angle I wanted (I actually made one, filled it, moved the dancing ants, and so on). Then, using the same technique, I created the shadow for the lower platform, the upper platform, and finally the bed top itself. It took a little imagination to determine where the shadow would fall and how the planes would change its perspective, but in a matter of under 5 minutes, I came up with something that looked (I think) passable.

                    Let me know if you agree.
                    Attached Files

                    Comment


                    • #11
                      Nice work! I'll show it to the client, who at this point, I've talked into drop shadows. If they like it and will pay for it, I'll send you the work if you want.

                      I'm way over my estimate on this one and can't afford to put any more time into it.

                      THANK YOU, EVERYONE, for working on this problem. On one hand I wish it had been a formula thing I just couldn't figure out... but on the other, at least I'm not quite as much of a lame brain as I thought. If it can't be done by the RTP guys, it can't be done.

                      You guys all rock. Thanks again.

                      Chip

                      Comment


                      • #12
                        Nice one Jason, a clear example of the power of lateral thinking.

                        Comment


                        • #13
                          Interesting approach, Jason. Thanks.

                          Sean

                          Comment


                          • #14
                            Hi everybody,

                            Jason,

                            after unsuccesfully trying various methods, I had come to the same conclusion: split the shadow in different parts .... In theory, I knew I had the solution, but I just couldn't make it look right in practice ... .... So.... great job!!!

                            Comment


                            • #15
                              Originally posted by Chip Hildreth
                              Nice work! I'll show it to the client, who at this point, I've talked into drop shadows. If they like it and will pay for it, I'll send you the work if you want.

                              I'm way over my estimate on this one and can't afford to put any more time into it.

                              THANK YOU, EVERYONE, for working on this problem. On one hand I wish it had been a formula thing I just couldn't figure out... but on the other, at least I'm not quite as much of a lame brain as I thought. If it can't be done by the RTP guys, it can't be done.

                              You guys all rock. Thanks again.

                              Chip
                              If they're interested, send me the details.

                              Thanks!

                              [email protected]

                              Comment

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