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Spotlight casting shadow of itself

HorusRaHorusRa Posts: 1,662
in The Commons

I've not noticed this before but lately I've been seeing in test renders a shadow of a ball. It didn't take long to figure out it was coming from the Spotlight. What would cause this?
I have a distant light that is ​pointing in the direction of the spotlight and I understand thats what is causing the shadow, but I never thought the geometry of a light,​ in this case a spotlight, was supposed to produce a visible shadow of itself. See attachment. It seems to be the ball that the arrow is pointing at that is casting the shadow.

Spotball.jpg
986 x 844 - 234K

Comments

  • Serene NightSerene Night Posts: 17,560

    Yes it is annoying that Iray does that. You may just have to move the light back some,

  • HorusRaHorusRa Posts: 1,662
    edited March 2019

    surprise​ Oh my lordy. I must have been very lucky to never have seen this before. I was sure I did something wrong, I would never have guessed that this would would even be possible.
    ​Thanks S.N., I will adjust as needed then.

    Post edited by HorusRa on
  • Richard HaseltineRichard Haseltine Posts: 96,888

    This is not a bug - think of a very faint light nearby and a more distant light further away - the near light source should show as a shadow in the light from the more distant source. Usually the effect will not be visible but if it is that reflects the way real lights would behave.

  • HeraHera Posts: 1,952

    I've actually seen it in real life, in churches and theatres, when huge spotlights shine upon lamps with bulbs in, then the bulbs cast shadows even if they are on. The effect is especially notable with these modern, transparent lamps, they cast shadows like thin spiderwebby things upon the object (say, a wall) behind.

  • mjc1016mjc1016 Posts: 15,001
    Hera said:

    I've actually seen it in real life, in churches and theatres, when huge spotlights shine upon lamps with bulbs in, then the bulbs cast shadows even if they are on. The effect is especially notable with these modern, transparent lamps, they cast shadows like thin spiderwebby things upon the object (say, a wall) behind.

    Yep...and as someone who has done stage/set lighting, it can be a right pain in the posterior...

  • HorusRaHorusRa Posts: 1,662
    edited October 2016

    It would be great if it actually looked like any of those things but it doesn't. It looks just like an artifact that should not be there. It is a semi-hard shadow of a ball that does not look like it's attached to an enclosure or anything, it doesn't look like a reflection/shadow of a light bulb. If it could even be remotely aligned with any stage lighting the closest would be a mirror ball. This is a ball in the middle of nowhere on the plain side of a church wall (outdoors at that), that I'll have to deal with accordingly.

    Post edited by HorusRa on
  • mjc1016mjc1016 Posts: 15,001

    The problem is more noticeable because you are using a distant light.  With an HDRI dome light it would be much less noticeble, if there at all.  It would probably be somewhat noticeable with the Sun/Sky lighting, too.  Distant lights are not really something that should be used in Iray.

  • HorusRaHorusRa Posts: 1,662
    mjc1016 said:

      Distant lights are not really something that should be used in Iray.

    Note aknowledged. Where do you guys get all this wonderful info quaoted just above? smiley I have never heard that before.

  • Richard HaseltineRichard Haseltine Posts: 96,888
    HorusRa said:

    It would be great if it actually looked like any of those things but it doesn't. It looks just like an artifact that should not be there. It is a semi-hard shadow of a ball that does not look like it's attached to an enclosure or anything, it doesn't look like a reflection/shadow of a light bulb. If it could even be remotely aligned with any stage lighting the closest would be a mirror ball. This is a ball in the middle of nowhere on the plain side of a church wall (outdoors at that), that I'll have to deal with accordingly.

    You could always build a support for it from primitives - the problem is that at the moment it is a free-floating object.

  • HorusRaHorusRa Posts: 1,662
    Richard Haseltine said:
    HorusRa said:

     

    You could always build a support for it from primitives - the problem is that at the moment it is a free-floating object.

    True. I may just be able to get rid of this particular spotlight, I was only using it for a backfill anyway, it's not really ​doing a whole lot. I don't think theres much difference when I test-deleted it.

  • fastbike1fastbike1 Posts: 4,074

    @HorusRa

    If your spotlight has the default geometry (point), that's the shadow that you are seeing, not the "spot ball" in your attachment.

    Iray casts shadows of all objects in a light path. The distant light mimics a sun, which will cast hard shadows.

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