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Shadows in Iray

geoff6geoff6 Posts: 250
in Technical Help (nuts n bolts)

Hi all,

Slowly getting my head around Iray and have a question (have millions but this will do for now) concerning interior lighting.

I'm using an enclosed set, environment set to scene only and it is lit with 2 photometric spotlights. It looks great but both spotlights are creating shadows which I would prefer not to have. I have set the shadow settings on the spots to none and all the shadow adjustments to zero and yet I still get shadows cast by the spots.

So my question is... What haven't I done, what have I done and how do I make it stop? Okay, that's three questions.

Also, I believe it's possible to make a primitive emit light. Howdoyoudothatthen?

Thanks in advance,

G

Comments

  • larsmidnattlarsmidnatt Posts: 4,511
    edited September 2015

    you can't turn off shadows for Iray, that was for 3DL.

    What you can do is soften your lighting. Either dont use spotlights and/or add an ambiant light source.

    Using a mesh light of the appropriate size could also work to soften shadows.

    Post edited by larsmidnatt on
  • geoff6geoff6 Posts: 250

    Aha! Okay, thank you for that larsmidnatt.. Can I trouble you with the question of ambient light? What might I use for that? Is this a primitive as an emitter and if so, how do I set that up?

     

    Thanks in advance,

    G

  • larsmidnattlarsmidnatt Posts: 4,511
    edited September 2015

     BTW be sure to use a very simple geometry for the light source, the more geometry the more points of light. Also if you only need the light to go in one direction a plane or curved plane may be better than a  sphere.

     

    Stolen from SY

    http://sickleyield.deviantart.com/journal/Tutorial-Getting-Started-With-Iray-519725115

    2. Mesh lights.  A mesh light is any object in your scene that has the Iray shader and has its emission set to a color other than black in the Emission channel in the Surfaces tab.  The Emission color only really affects light color if the temperature (in K, or Kelvin) is around 5000-6000.  Temperatures below 4500 will be more orange or red; temperatures above 6500 will trend increasingly toward blue.  There is good documentation of color temperatures for light online. 

    I mostly use Octane so I don't know the best settings in Iray to get lights working, but hopefully that can get you lookin in the right direction. Might take some tinkering.

    Post edited by larsmidnatt on
  • geoff6geoff6 Posts: 250

    Yep, got it now just watched the video a for the third time and finally it's making sense! Thanks for that.

    G

  • ronmolinaronmolina Posts: 118

    You can also change the geometry of the spot light in the spotlight settings which will soften the shadows. No need to use a mesh light as the Iray spotlight already has that built in.

  • Oso3DOso3D Posts: 15,011

    It's highly recommended that anything that doesn't absolutely have to glow in frame be handled as spot or point with geometry (which basically turns them into an optimized primitive). This is a big way to soften light.

     

    Another possibility, though more 'costly' in render time, is using translucent screens between light source and scene, or relying on scattering light off of walls and such. (Slower, but very natural looking)

     

  • ToborTobor Posts: 2,300
    geoff6 said:

    I have set the shadow settings on the spots to none and all the shadow adjustments to zero and yet I still get shadows cast by the spots.

    Something's not quite right. When you have Iray selected as the renderer, and you add a new spotlight, there are no options for shadows, UNLESS you also have Interactive selected for the Render Mode, instead of the usual Photoreal.

    So the first thing to do is double-check your Iray settings. Go to the Render panel, click on Render Mode, and see what that says.

    1. If it says Photoreal, your newly added lights will not have a shadow control option. It simply will not be shown. Shadows are a given in Iray Photoreal.

    2. If it says Interactive, your lights will have a shadow control option, and it should function. In Interactive move you can control various aspects of shadows.

    It's important to be using spotlights created in vfersion 4.8. These are "universal" and allow you to use the same light for both Iray and 3Delight rendering. Other specialy light types may not support the automatic switching. If you have light sets from older products, avoid using them for now.

  • jestmartjestmart Posts: 4,449

    The options will still be visible if you have Show Hidden checked, they will just be greyed out to indicate that are meant to be hidden and not used.

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