Tutorial Uber Area Lighting: The Basics

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  • tl155180tl155180 Posts: 994
    edited December 1969

    Thanks for the help. I don't have Photoshop (or know how to use it for that matter) but I'm starting to learn GIMP, so maybe I'll be able to do something similar.

  • SzarkSzark Posts: 10,634
    edited December 1969

    I have GIMP and you can do exactly same process as I described.

  • tl155180tl155180 Posts: 994
    edited December 1969

    Cool, I'll give it a try. Thanks Szark!

  • SzarkSzark Posts: 10,634
    edited December 1969

    no worries if you get stuck just shout.

  • tl155180tl155180 Posts: 994
    edited December 1969

    Hey Szark. You know the parameters involved in "falloff" with the uber area lights - do you know if theres a way to tell what the figures in 'Falloff End' represent in terms of distance?

    I usually just end up guessing and using trial and error to work out how far the light is reaching, but it'd be good if it was possible to be more accurate about it.

  • SzarkSzark Posts: 10,634
    edited December 1969

    DS use CM as a unit so 100 CM = 1 MTR. But to get a realistic fall off in relation to the intensity is still guess work I am afraid.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,412
    edited March 2015

    Yea, what Szark said. I look at the scene, and say; The light is at +X 250, and that back wall is at -X 250. So that is 500 Daz Studio Units. add a zero (5,000) and plug it into the Uber Light "max Distance". It's about as accurate as the Windows98 way of making a Swap file, Twice the RAM, regardless how much RAM was in the computer, lol.

    Post edited by ZarconDeeGrissom on
  • tl155180tl155180 Posts: 994
    edited March 2015

    Szark said:
    DS use CM as a unit so 100 CM = 1 MTR. But to get a realistic fall off in relation to the intensity is still guess work I am afraid.

    This may be a very stupid follow-up question, but how do I know how far 100cm is in the viewport? Cos obviously we're not talking real life cm and metres here (otherwise that'd be off my screen and across then room). I know there are those gridlines on the floor... are they 100cm square each?

    Post edited by tl155180 on
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,412
    edited March 2015

    I don't know what those lines are at. It's another reason I use my Test chamber to start setting up a scene (I mostly work in British Imperial). I make a primitive plane the size I need (say forty feet), and set the tile X and Y to 40. Each tile on the floor is one foot in size.

    example.
    http://www.daz3d.com/forums/discussion/47738/

    Here is some metric based maps, (FREE)
    http://www.daz3d.com/forums/viewreply/666497/
    (EDIT)
    And a color scale cube can always be usefully to play with.
    http://www.daz3d.com/forums/viewreply/697733/

    Post edited by ZarconDeeGrissom on
  • tl155180tl155180 Posts: 994
    edited December 1969

    Thanks for the advice guys.

    I just did some testing moving a couple of cameras around the scene and it looks like the gridlines on the floor of the viewport are 100cm x 100cm each. This'll give me a much better idea of how far I'm sending the lights when using fall-off - thanks!

  • SzarkSzark Posts: 10,634
    edited December 1969

    Yeah 1 mtr squares and FYI you can create Cubes at any size you want and use as a measure. ;)

  • Mustakettu85Mustakettu85 Posts: 2,933
    edited December 1969

    Hi folks,

    I don't remember if this has been mentioned here, so I'll post.

    I was re-reading Omnifreaker's documentation and I found out that if you activate falloff but set both distances to the same value (say, 0), UberAreaLight will decay like any other light shader, over infinity.

    So using a falloff of 2 (square) and two zeros for distances will give you a "physically-based" area light.

  • SzarkSzark Posts: 10,634
    edited December 1969

    oh man I missed that info. Another thing to test. Oh cool you got me in the zone with that ray trace conversation and now this....thanks.

  • mjc1016mjc1016 Posts: 15,001
    edited December 1969

    Szark said:
    oh man I missed that info. Another thing to test. Oh cool you got me in the zone with that ray trace conversation and now this....thanks.

    I've been trying to cram 9 months worth of missed info into the past couple of weeks...I don't know if my 'too test' pile will ever shrink.

  • SzarkSzark Posts: 10,634
    edited December 1969

    Tell me about it.

  • tl155180tl155180 Posts: 994
    edited December 1969

    Hi folks,

    I don't remember if this has been mentioned here, so I'll post.

    I was re-reading Omnifreaker's documentation and I found out that if you activate falloff but set both distances to the same value (say, 0), UberAreaLight will decay like any other light shader, over infinity.

    So using a falloff of 2 (square) and two zeros for distances will give you a "physically-based" area light.

    Does this actually work? I just tried it and all it did was give no light at all. Unless I'm doing it wrong somehow....

  • SzarkSzark Posts: 10,634
    edited December 1969

    Yes I get light with that so what are you using as a light source is the first question?

  • tl155180tl155180 Posts: 994
    edited December 1969

    Szark said:
    Yes I get light with that so what are you using as a light source is the first question?

    I just did a test scene - I put a figure in the viewport and stuck an UberAreaLight disc in the sky pointing downward at a 45 degree angle. Then just switched Falloff to 'on' and left everything else untouched. It emitted no light.

  • SzarkSzark Posts: 10,634
    edited December 1969

    A make sure it is pointing the right way but first crank up the light intensity to something high like 5000% and test first. If nothing then make the disc -45%

  • tl155180tl155180 Posts: 994
    edited March 2015

    Szark said:
    A make sure it is pointing the right way but first crank up the light intensity to something high like 5000% and test first. If nothing then make the disc -45%

    Nope, doesn't work for me. Just so I'm ultra clear that I'm doing it the right way - I've basically pointed a simple UberAreaLight disc at Genesis2Female. I switched on Falloff and changed the settings so that start was 0 and end was 1000 - no problem; I got plenty of light on the figure.

    Then I changed the falloff parameters to start 0 and end 0 - nothing, no light. Thats all I did.

    Then I tried start 10 and end 10 - still no light. The disc is definitely pointing the right way.

    Post edited by tl155180 on
  • SzarkSzark Posts: 10,634
    edited December 1969

    Ok then it is about the intensity and distance the disc is away from the figure. So try a really high light intensity value of 20000%

  • tl155180tl155180 Posts: 994
    edited December 1969

    Szark said:
    Ok then it is about the intensity and distance the disc is away from the figure. So try a really high light intensity value of 20000%

    Ah-ha! Bingo! You're right. The intensity had to be much higher than normal for the light to register.

    Cool - thanks Szark! :D

  • SzarkSzark Posts: 10,634
    edited December 1969

    my pleasure tl155180 glad I could help

  • tl155180tl155180 Posts: 994
    edited March 2015

    I used your advice the other day to work out a way to create a nice effect for sunlight pouring into a room through a window. I setup the distant light coming in from outside and added the UE2 as usual. Then I applied UberAreaLight bases to the window glass, facing inwards to simulate the spread of the sunlight and set those light bases to opacity 0%. This is only a rough example, it needs cleaning up a bit, but I think it worked pretty well.

    You've been a big help Szark, thanks.

    CD_Distant_Light_150%_AreaSurface_Light_on_Windows_150%_UE2_100%.jpg
    1356 x 1084 - 818K
    Post edited by tl155180 on
  • SzarkSzark Posts: 10,634
    edited December 1969

    for a test that is coming along nicely.

  • tl155180tl155180 Posts: 994
    edited December 1969

    Are you bummed that UberAreaLight might become a thing of the past now that Iray is here with its own lights?

  • SzarkSzark Posts: 10,634
    edited December 1969

    ROFLOL nope

  • HorusRaHorusRa Posts: 1,660
    edited April 2015

    Thanks for writing such a wonderful tutorial. A few questions though:
    a) Where are u finding the 'Refraction' and 'Index of Refraction' properties? I'm Not finding them under the surface properties for the glass. I did however find them under the properties for the entire sconce.
    b) How or where did you find the fire texture in the fire place. I'm not finding that, I don't believe. I did find the entire fire place textures all on one sheet, so to speak. Later I did find what seemed to be a fire texture but it was black and white. Might this be what u put in Gimp?

    Post edited by HorusRa on
  • SzarkSzark Posts: 10,634
    edited December 1969

    My pleasure

    a) This shader replaces the default shader and removes Refraction etc which is a little limiting IMHO. But you could use a Geometry Shell (Create > New Geometry Shell) as the light source which will keep your existing shader intact on the original mesh.
    b) the fire texture is part of http://www.daz3d.com/yuletide-dreams which is a texture addon for http://www.daz3d.com/holiday-nook

    Yuletide.jpg
    1680 x 1050 - 1M
  • SzarkSzark Posts: 10,634
    edited December 1969

    PS the black and white fire texture is for Transparency (Opacity Daz Studio calls it)

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