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Couple questions about accurate Iray sun

SnowSultanSnowSultan Posts: 3,776
in The Commons

I was just experimenting with the Iray Sun/Sky settings and found that if you lower the Environment Intensity to 0.30, you get a nice visible sun and retain a fairly well-lit scene. There are a few things about it that are proving to be a little confusing though.

 

- Should the SS Latitude and Longitude be set to the scene's real-world coordinates if trying to create physically accurate lighting? (for example, 36.114, -115.17 for Las Vegas). Same for the UTC Offset, that should also be set according to where you are imagining your scene (using this list for example: https://en.wikipedia.org/wiki/List_of_UTC_time_offsets)? 

- If I change the SS Time, the sun proceeds to rise in the west (assuming the west is left when viewing a scene from the Front) and sets in the east. Well that's not right.   :)   Can anything be done to make the sun rise from the right side and set on the left?

 

Thanks in advance.

Comments

  • mjc1016mjc1016 Posts: 15,001

    I believe it was mentioned in the Iray intro threads, that you are looking south (or more accurately...the character is facing north) when in Front view...that would east on the left and west on the right.

  • SnowSultanSnowSultan Posts: 3,776

    Thanks, that explains that part at least.  :)

  • Collective3dCollective3d Posts: 446

    Also, "dome rotation" will affect the way the sun/sky behaves, with or without the sundial prop.

    For instance, if I have my sundial prop in the scene, and have the azimuth set so i am looking into the sun, but the dome rotation is set to 180, the sun will actually be behind me.  Not exactly sure it works that way without the sundial prop.

     

  • Oso3DOso3D Posts: 15,085

    Yeah, I just mess with 'time of day' and dome rotation and ignore the rest. Makes life a lot easier.

     

  • SnowSultanSnowSultan Posts: 3,776

    Right, I was just wondering about those settings if one needed to create physically correct and time-accurate lighting. I will use whatever is necessary to make a render look good regardless of realism, but these things are still good to know.  :)

  • vwranglervwrangler Posts: 4,972

    I have to admit, not wanting to figure all that stuff out is one of the reasons I picked up the Longitude/Lattitude for Iray product back during the PA sale. Trying to figure all that out is really vexing.

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