9 Replies Latest reply on Aug 21, 2018 11:53 AM by Damir Galic

Lights casting shadows from confined space?

Damir Galic Aug 16, 2018 2:28 AM

Is this hardware limitation or can it be fixed?

Shadows are cast if I put a light (all directional) from within some vessel. In that case shadows are cast everywhere.

Is there a solution for this? Turning off environment shadows helps a bit, but I don't think this is a solution.

This is a bit logical if the light was actually visible, so everything else would get darker, but if it's not visible it's illogical to have all the shadows.

Re: Lights casting shadows from confined space?

Marcel De Klein Aug 16, 2018 4:13 AM (in response to Damir Galic)

Hi Damir,
I've done a small test in my Visualize 2018 SP3 version. I created a scene containing a vessel and some objects around it. I've put an all directional light inside the vessel. However in my test, there is no leaking of light at all, nor are any shadows cast because of the light.

Did you, by accident, use a transparant material or a subsurface material. In that case, in my test, shadows are cast everywhere.

If you'd like you can send me a part of your scene and I'll have a look at your model.

Best regards,
Marcel
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- Re: Lights casting shadows from confined space?
  
  Damir Galic Aug 16, 2018 4:31 AM (in response to Marcel De Klein)
  
  Hi,
  what about if there is a little opening in that box, but light still not visible?
  
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  - Re: Lights casting shadows from confined space?
    
    Marcel De Klein Aug 16, 2018 4:43 AM (in response to Damir Galic)
    
    Hi Damir,
    Maybe I misunderstood your question. If I recap, as I understood, you have a light source in a confined space, which causes to cast shadows everywhere. This is something which should not be happening. (In my test Visualize renders as it should).
    When there is a little opening in the box, it may cause some casting of shadows, however not all around.
    When there is a little opening in the box, but the light is not visible, it still may cast some shadows because of caustics, but that effect would be very small.
    
    May I ask why you have put a light source inside a confined space? What is the goal you try to achieve?
    
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    - Re: Lights casting shadows from confined space?
      
      Damir Galic Aug 16, 2018 5:07 AM (in response to Marcel De Klein)
      
      This is one of examples where without interior light nothing is visible.
      However this casts shadow. Not sure if it darkens other stuff also, but probably does. I lowered brightness to 0,4 because at 1 shadow is a lot more intensive.
      
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      - Re: Lights casting shadows from confined space?
        
        Marcel De Klein Aug 16, 2018 5:28 AM (in response to Damir Galic)
        
        Thanks for the image. I understand what you are trying to do.
        The interior light casts shadows, that's correct. In Visualize Preview you have the option to turn of the casting of the shadows. In your case it would be helpful to have this option also for fast and accurate modes, so you can use the Interior light as a fill light. Unfortunately Visualize doesn't has that option (to my knowledge). Would be a great new feature Brian Hillner.
        
        Have you tried to play around with Global Illumination to brighten up the interior of your vessel? It might give you a more realistic and visible look and the shadow will be cast in the correct direction.
        Or maybe an Area Light - Disc, placed in your cut-out and pointing to the inside of the vessel with a very low brightness.
        
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        Re: Lights casting shadows from confined space?
        
        Damir Galic Aug 16, 2018 8:39 AM (in response to Marcel De Klein)
        
        I think the only reasonable way is not to rely on hdr lights but use those directional lights that were imported from solidworks. That illuminates everything a bit better.
        
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      - Re: Lights casting shadows from confined space?
        
        Heiko Sohnholz Aug 16, 2018 12:11 PM (in response to Damir Galic)
        
        … or you add an emissive appearance in the inside of the vessel. If necessary your are able to add a sphere e.g. as a new geometry inside.
        
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        Re: Lights casting shadows from confined space?
        
        Brian Hillner Aug 16, 2018 10:20 AM (in response to Heiko Sohnholz)
        
        I would try with a new Area Light (Visualize Pro only) and use a Disc as Marcel suggested.
        Then if you're not happy with that, I would try Heiko's suggestion of the emissive appearance on basic geometry (like a sphere that you stretched).
        Reason why I say try the Area Lights first, is because those work in Fast mode as well.
        
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Re: Lights casting shadows from confined space?

Damir Galic Aug 21, 2018 11:53 AM (in response to Damir Galic)

Hmmm this is what I would need in this case: NVIDIA GeForce Keynote - IGN Live at Gamescom 2018 - YouTube
Not fake spot light but global illumination light.
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