20 Replies Latest reply on Feb 1, 2013 1:36 PM by Dwight Livingston

    Sink lines on extrusions? PhotoView360 SW2013 SP1.0

    Greg Tabberer

      Hi all,

       

      Since upgrading to SW2013 I have had some rendering issues in PhotoView 360. When I render an extruded profile, say a box section which has a flat external surface with webs attaching to the internal face of the profile, PV360 has introduced unwanted sink lines. These are showing as shadowy lines along the flat face (see picture attached).

      sink lines on extrusion.JPG

      Initially, when only one web was present, I thought that this was something being picked up in the background scene which didn't used to be picked up in 2012 and so ignored them to start with. But in this quick render I have added extra internal webs which has further highlighted the problem.

       

      As I am doing renders for marketing material and I work for a PVC extrusions company these sink lines are completely unwanted as they do not appear on the final product - our extrusion tolerances on these seen surfaces are specifically high to avoid this happening on the final product.

       

       

      I have looked through all the options I can find for PV360 but cannot find anything that I would relate to this as an issue. NB caustics and bloom are turned off, and the surface is flat when in standard SW2013 view.

       

      If someone could help me with this it would be greatly appreciated.

       

      Many thanks, Greg

        • Re: Sink lines on extrusions? PhotoView360 SW2013 SP1.0
          Rob Rodriguez

          Is the "face" made up of one extrusion or are you staking multiple extursions?

           

          What appearance are you using?

          • Re: Sink lines on extrusions? PhotoView360 SW2013 SP1.0
            Ron Bates

            Rob is correct in that PV is not affected by the "edge bleed through" issue.

             

            The problem here is the appearance.

             

            Greg - I assume you're using White Low Gloss Plastic.

             

            The low gloss plastics have actually always been set up to have a bit of sub-surface sattering...which is a transparent effect (like skin or wax).  Until 2013, this SSS value was being ignored.  But now it is being properly honored.

             

            Try using one of the Solid appearances (Solid folder) which are plain diffuse appearances or use a medium or high gloss plastic and reduce reflectivity and specular.

             

            Ron

              • Re: Sink lines on extrusions? PhotoView360 SW2013 SP1.0
                Greg Tabberer

                Hi Ron thanks for your - and Rob's - input. Thinking back to earlier SW versions I do remember having the "edge bleed through" isssue in the solid modelling view (ignored it at the time) but never before in the rendering view. That is definitely not what's happening now - modelling views are all fine (ambient occlusion etc.) it's just when I do a rendered preview / full render in PV. So your explaination of SSS in PV makes a whole lot of sense.

                 

                Yes White Low Gloss Plasitc was my material of choice before. I've just changed over to Medium Gloss and that appears to have removed the issue entirely.

                 

                I'll bear in mind the potential SSS value from now on, though it would be very useful if this was shown somewhere in the material options so that you could do some manual tweaking if you chose to like the other values.

                 

                Thank you! Greg

                • Re: Sink lines on extrusions? PhotoView360 SW2013 SP1.0
                  Dwight Livingston

                  Ron

                   

                  I am glad to hear your explanation and a workaround. That is very helpful. I do, though, wonder if this is working as intended.

                   

                  Dwight

                • Re: Sink lines on extrusions? PhotoView360 SW2013 SP1.0
                  Ron Bates

                  Greg - SSS amount is one of those controls we consider a bit advanced so it's intentionally hardcoded in certain presets.  But the ability to tweak it is not an impossibility.  Enough users just need to scream (ok...shout loudly) that "we need this!".

                   

                  Dwight - I guess I'm not sure what you mean exactly by weather it's intended..  I can say that it is absolutely working as designed, in that the preset has SSS, and therefore it should look like this. Thinner parts of a model will appear translucent.  Should the Low Gloss Plastic appearances have SSS though????  Maybe that's what you're asking??  To me that's the real question.  The presets were initially created for us when standalone PV 360 came out in 2009, by a contractor/artist who is a Modo materials expert.  I don't suspect that the addition of SSS to low gloss plastic was a mistake...but rather an explicit judgement call.  I chose to leave them as they were originally designed by the artist, and not remove the SSS they had on them.

                   

                  To further the overall explanation, what really happened is that we added a bunch of new apperances in 2013 (many new liquids, new solid marbles, wax, etc.) and most of these do have translucent characteristics in real life so they were created with SSS amounts as well.  The problem in 2012, was that the visibility of SSS on appearance presets was limited to direct lighting only (ie only seen when using a directional/spot/point light in your rendering).  By default, we don't use physical lights in PV...rather we light the model exclusively by the high dynamic range (HDR) image that is part of the scene.  In other words, you would have seen the SSS in low gloss plastics in 2012 ONLY IF you used physical lights in your model/scene...but since using physical lights is not a default workflow, the difference in how low gloss plastic looked when using physical lights, was largely overlooked.  Come back to those new 2013 apperances I mentioned which use SSS (wax, marble, etc).  If they only looked good/real when you enabled some physical lights in the scene, this would be pretty bad.  You'd have all these new materials that wouldn't look real, out of the box, until you did some more stuff.  So we modified the global render settings, to enable SSS affects to be visible by both direct (physical) lighting AND indirect (HDR) lighting.  The result is that renders of thin walled parts that were previously made of low gloss plastic, now look different b/c the SSS affect is now visible with indirect (HDR) lighting.  Perhaps more detail than you were really looking for...but that's how it all went down ;-)

                   

                  PS - since I mentioned the other appearances, here are a couple test renders I did with them when we were developing them for 2013.

                   

                  Stone/architectural/marble/jade dull

                  Jade_dull.JPG

                  Plastic/wax

                  Wax2.JPG 

                    • Re: Sink lines on extrusions? PhotoView360 SW2013 SP1.0
                      Dwight Livingston

                      Ron

                       

                      That answers my question, that the translucency is an intended effect and not just a technique to help make generic plastic look low gloss. I assume SW feels that medium and high gloss generic plastics have as much translucence, but perhaps using SSS interferes with showing gloss?

                       

                      I think my vision of a generic low gloss plastic would be something like a PC/ABS blend with plenty of TiO2 and a surface texture from an etched mold. It would not be translucent like wax or jade. That's just me, but I glad to learn about this so I can maybe avoid generic low gloss plastic.

                       

                      When I edit the "white low gloss plastic" appearance, the transparency is set to zero. So this SSS is something different, a hidden control? That is frustrating. I figured I'd have full control of appearances in the advanced edit controls. Of course I'm on SW2011 so maybe it's a version thing.

                       

                      Anyway, thanks for the info.

                       

                      Dwight