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      |  |  | "Kevin Clague" <kevin_clague@yahoo.com> wrote in message news:H90qHs.CCn@lugnet.com...
 > Mike,
 >
 >   In the first image, there are no shadows.  What you see are reflections.
 
 I suspected as much when I really started to look at it after you noted that
 you were using a shadowless light source.
 
 
 [ ... snipped ... ]
 
 >
 >   Ambient light comes from *all* directions, and therefore creates no
 > shading.  Diffuse light comes from a specific point, and therefore can
 > produce shading and shadows.  In POV-Ray, diffuse means the shading part  of
 > rendering and is controlled in the surface description of the model (it is
 > packed into the Color definitions by L3P.)  Shadows on the other hand are
 > defined by the light sources themselves.
 >
 >   LPub automatically turns off shadows in building instruction images
 > (whether you want them or not (do I feel another option control request
 > brewing?)).  The default settings for ambient and diffuse used by L3P are
 > 0.4 for ambient and 0.4 for diffuse.  In my previous experience with
 > lighting models, it was my understanding that it was desired to have  ambient
 > + diffuse + reflection equal to 1, so when I turned off reflections, I
 > modified ambient and diffuse so they totaled one.
 >
 >   Back to my pistons that were too dark on the underside....  I realized
 > that the undersides were darker than the tops because the diffuse light  was
 > lighting the top, but not the bottom.  To reduce this brightness  difference,
 > I increased the ambient levels, and decreased the diffuse levels, but made
 > sure they added up to 1.
 >
 >   For sport you can try two extremes:  ambient 1.0, diffuse 0 (which will
 > give you shading less images like LEGO uses), or ambient 0 and diffuse 1
 > (which makes any unlighted surface black.  There are those that render
 > building instructions with only ambient (before the ambient controls, they
 > used the POV-Ray quality settings to make this happen.)
 >
 >   LPub/L3P lets you define how many light sources you want and what their
 > placements are, and those lights are used when creating building
 > instructions. So if you want a different lighting configuration than what
 > L3P defaults to, you can set that up in the L3P->Lights tab of LPub's
 > configuration controls.
 
 This is really useful.  I need to sit down with a less complex model and run
 through all of the various settings.
 
 >
 >   On the topic of patience, I feel the same way.  I'm new to building
 > instructions, and you and Steve Barile have been at it a while.  Thanks  for
 > your patience and input on how to make LPub better suite your needs.  I'm
 > enjoying the synergy that is happening on the topic of building  instructions.
 >
 > Kevin
 
 Happy to provide input and I appreciate your interacting with the community
 so openly.
 
 Mike
 
 
 --
 Mike Walsh - mike_walsh at mindspring.com
 http://www.ncltc.cc - North Carolina LEGO Train Club
 http://www.carolinatrainbuilders.com - Carolina Train Builders
 http://www.bricklink.com/store.asp?p=mpw - CTB/Brick Depot
 
 |  |  |  
 
 Message is in Reply To:
 
  |  |  | Re: Sand Green and POV 
 | 
 |  | Mike, In the first image, there are no shadows. What you see are reflections. The reflection of the smoke stack on the top of the engine compartment looks like a shadow because the smoke stack is darker than the abient light you see other places. (...)   (23 years ago, 20-Jan-03, to lugnet.cad, lugnet.inst, lugnet.cad.ray) 
 |  24 Messages in This Thread:
 
      
                    
             
                     
        
      
        
 
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