5 Replies Latest reply on Dec 18, 2011 4:58 AM by The Scarlet Avenger

    Preserving the look of a multiplied top layer without the bottom layer

    The Scarlet Avenger

      Hi.

       

       

      I have a problem I've been trying to solve for weeks. I've created blood that goes over a person's clothes in Photoshop. The person is, of course the bottom layer and the blood is made out of a series of layers of blood elements against white that I've multiplied together.

       

      Basically, I want to get rid of the base layer and then import the photoshop file into Nuke and composite the blood over a video segment of the person. However, there doesn't seem to be any way in photoshop to rasterize the result of the multiplied pixels on the blood layers. Am I missing something?

       

      Why can't I just preserve the multipled look of the blood on the blood layers and remove the bottom layer? It seems like the bottom layer is required to see the result of the multiplied blood. Any help would be hugely appreciated.

       

      -Scott


        • 1. Re: Preserving the look of a multiplied top layer without the bottom layer
          c.pfaffenbichler Level 8

          Please read the explanation of Blend Modes in general and the Blend Mode Multiply in the Help.

          In the pdf-version I downloaded some time ago (Last updated 4/9/2010) that’s on page 300, headlined »Blending modes« and »Blending mode descriptions«.

           

          I don’t know Nuke, but can’t you multiply there?

           

          If you want the flattened effect flatten the image and, if necessary, use the transparencies and masks of the previously existing Layers to mask the resulting Layer.

          Could you please post a screenshot of the image with the pertinent Panels visible?

          1 person found this helpful
          • 2. Re: Preserving the look of a multiplied top layer without the bottom layer
            The Scarlet Avenger Level 1

            Blend_Problem_Example.jpg

             

             

            Hi,

             

            Thanks for the quick response.  The above picture should illustrate what I'm talking about.  I used three warped and multiplied versions of the blood sample above over the background layer of the actor.  You can see the result of the multiplications.  I want that result (without the background plate) so that I can bring it into Nuke (doesn't matter what software) and composite it over top of video of the actor.  I'm using Photoshop to create the blood, because Nuke's paint system is terrible.  If it had a good paint system, I wouldn't bother with photoshop at all and would do all my blending with Nuke.  However, I can't figure out a way to preserve just the result of the multiplication, without having the background in place.  When I remove the bg layer, I get this....

             

            Blood_Patch 2.jpg

             

            This isn't right.  And when brought into Nuke and overed looks even more wrong

             

            Nuke_Ex.jpg

             

            This isn't a Nuke/photoshop integration issue.  There doesn't appear to be a way to preserve the result of the multiplication, without the background layer.  Or is there something I'm unaware of?  Thanks.

            • 3. Re: Preserving the look of a multiplied top layer without the bottom layer
              c.pfaffenbichler Level 8

              This isn't a Nuke/photoshop integration issue.  There doesn't appear to be a way to preserve the result of the multiplication, without the background layer.  Or is there something I'm unaware of? 

              Have you read the items on Blend Modes?

              Blending Modes determine how a layer’s content interacts with underlying layers’ content to determine the resultant appearance, so naturally removing the background has an effect (edit:) with a Blend Mode like Multiply.

               

              (doesn't matter what software)

              I’m pretty certain Adobe’s video software like After Effects supports Blend Modes like Multiply.

              And are you familiar with Photoshop’s own animations features?

               

              Multiplication works both ways, so you might be able to invert the montage – there might be some difference, though.

              So you could try:

              Flatten all the top layers into one, move the background on top of that, set it to Multiply and Clipping Mask it to the underlying Layer (cmd-alt-G).

              • 4. Re: Preserving the look of a multiplied top layer without the bottom layer
                The Scarlet Avenger Level 1

                Thanks for the advice.

                 

                That cmd-alt-g seemed to isolate the blood as a normal blend layer.  Unfortunately, when I bring it into Nuke, it looks black and splotchy.  A true normal blend mode layer would come into Nuke fine, so I think Photoshop is not really able to bake the multiplication into a layer.  Very strange.

                 

                  Also, I do understand the concept of multiplication blend modes, however I thought Photoshop would retain the result of the multiplication, not be dependent on the background layer always being there.

                 

                     Nuke and photoshop should work together to sort this out as Photoshop is the king of still compositing and Nuke is the king of moving image compositing.

                • 5. Re: Preserving the look of a multiplied top layer without the bottom layer
                  The Scarlet Avenger Level 1

                  Actually, when I made a black layer beneath the blood and then made an alpha channel and brought it into Nuke, it worked.....finally!!!!  Thanks for the advice about putting the multiplication on top as a clipping mask