Tutorial Uber Area Lighting: The Basics

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  • SzarkSzark Posts: 10,633
    edited December 1969

    Good point Totte I will do that this arvo, thanks for the reminder.

  • SzarkSzark Posts: 10,633
    edited July 2013

    Update: I just added this to Post number 4 on page one.

    3: Totte asked me about how to avoid the Area light/s showing up in Reflections even though "Fathom" was turned on. I found it strange but we found the cure. Turn Opacity down to 0% for the Area Light. It will still emit light with Fathom on and Opacity at 0%.
    Post edited by Szark on
  • SertorialSertorial Posts: 960
    edited December 1969

    what if you put an area light tube inside a cloth lampshade? How do you get the lampshade to transmit the light in a realistic way? I tried reducing the opacity, but the lampshade gradually looks like it's disappearing (rather than being illuminated from within)

  • SzarkSzark Posts: 10,633
    edited July 2013

    You could make a mid grey trans map http://www.daz3d.com/forums/discussion/25377/ for the light shade so it is semi transparent when Opacity is to 100%. Also you could add Index Of Refraction for the fabric you want to simulate. http://forums.cgsociety.org/archive/index.php/t-513458.html at 100%. But if you use refraction it will drive the render time up and also make sure you have the Max Ray Trace Depth at the correct value. If the shade is singe skinned mesh then a Max Ray Trace Depth of 2 should do nicely which is the default. But you could get a way with 1 and reduce render times a little more. But if the shade is double skiined then 2 it will have to be.

    Or you could use the new SSS shader Base's translucency function. Don't ask me how to set it up because I can't use it without crashing so i haven't been able to keep current.

    Post edited by Szark on
  • SertorialSertorial Posts: 960
    edited December 1969

    Szark said:
    You could make a mid grey trans map http://www.daz3d.com/forums/discussion/25377/ for the light shade so it is semi transparent when Opacity is to 100%. Also you could add Index Of Refraction for the fabric you want to simulate. http://forums.cgsociety.org/archive/index.php/t-513458.html at 100%. But if you use refraction it will drive the render time up and also make sure you have the Max Ray Trace Depth at the correct value. If the shade is singe skinned mesh then a Max Ray Trace Depth of 2 should do nicely which is the default. But you could get a way with 1 and reduce render times a little more. But if the shade is double skiined then 2 it will have to be.

    Or you could use the new SSS shader Base's translucency function. Don't ask me how to set it up because I can't use it without crashing so i haven't been able to keep current.

    Thanks. I suddenly realised I could apply the ubersurface shader and dial up translucency. Worked a treat!

    :)

  • SzarkSzark Posts: 10,633
    edited December 1969

    I didn't suggest that because as far as I knew Uber Surface Transluceny is a cheat and not a pure translucent settings. I am a little surprised it worked to be honest. But hey I am here to learn to. Thanks.

  • VaskaniaVaskania Posts: 6,010
    edited July 2013

    I'm getting a bit of a headache trying to work this out myself. My image alone will probably tell you what's going on. lol
    This is Bridge of Cheirocrates loaded via the !Pre_Bridge file in the Les Romantiques Expansion. I changed all of the bulbs in the lights to uberarea surface lights (I selected the area and ctrl clicked uberarea base > ignore), and all of the surrounding glass is set with the 100% refraction with like 1.7 ior. I seem to be getting some strange issue where the lights aren't emitting the same amount, same direction, something. The glass also doesn't look as colorful on all of them. I can't get them to really "pop". I can turn up the intensity to like 1000% on the bulbs, and it's the same issue. 1-2 of the lights are extremely bright, and the other 2 not so much. This was rendered via Perspective, so there's no DOF or anything.

    The light emitting issue is really noticeable on the columns; the rear 2 are much brighter than the front 2. The glass... well.. just look at them. They're not at the same brightness. The shadowing on the bridge floor seems to be correct.

    There are no other lights in the scene, and the blocker is down @ the floor under the bridge.

    AreaLightsIssue.jpg
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    Post edited by Vaskania on
  • VaskaniaVaskania Posts: 6,010
    edited July 2013

    -removed as I didn't fix anything, it was a difference in my monitors, issue still persists-

    AreaLightsIssue_removed_shadows.jpg
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    Post edited by Vaskania on
  • SzarkSzark Posts: 10,633
    edited December 1969

    Ok I am here, been a tad busy.


    Ok so you applied Area Base to all lamps and no light is being emiitted, well not enough.

    Try this
    Glass Diffuse 50%
    Opacity 15 - 20%
    Multiply Through Opacity OFF
    Refraction 100% at 1.54

    Max Ray Trace Depth 2

    What are your Fall OFF settings too please.

    I don't have this set or I would test it myself.

  • VaskaniaVaskania Posts: 6,010
    edited December 1969

    The bulb and surrounding glass are two separate surfaces (as they would be realistically in a street lamp), which one(s) do I make which changes to?

    My fall off on the bulb is off atm. Even when turned on with start/end at 2000 there isn't much difference.

    The render settings already have RT depth to 2 (I have no separate RT depth in the surfaces pane, if I'm supposed to).

  • SzarkSzark Posts: 10,633
    edited July 2013

    Sorry the glass of the lamp shade not the light bulb. Jack 9 times out of ten makes the bulb and glass a separate surface which makes this sort of thing a lot easier to do. The trick is getting a good balance of glass detail and the intensity of the area light. Oh if you use Ambient on the Bulb you will make it glow as I showed at the end of the tutotail.

    Fall Off start and end at 2000? Try Start 0 and End 2000 which is 20 mtrs. But I would try 1000 and see how that goes too.

    Max Ray Trace Depth in the render settings yes. Good 2 should work perfectly.

    Oh use the main camera not Perspective to render through.

    Post edited by Szark on
  • VaskaniaVaskania Posts: 6,010
    edited July 2013

    Welp, bulbs are glowing, but lighting is still wonky. Rear columns are still brighter, and I seem to be having an issue where the lamp posts are less illuminated on the left side. This has falloff 0-2000, not sure it's much brighter than 1000 was.

    I'm not sure if angle has anything to do with it, but they're all @ the default 35 if that makes any difference.

    I know, crappy render, I'm using proof settings atm.

    UberArea_Falloff1000glowing.jpg
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    Post edited by Vaskania on
  • SzarkSzark Posts: 10,633
    edited December 1969

    Ok good now increase the intensity of the light.

    As for why light is hiting parts and not others as I don't have this set to look myself. But knowing how Jack models his stuff I would say they shouldn't be anything getting in the way.

  • VaskaniaVaskania Posts: 6,010
    edited July 2013

    Ok, we're cooking with crisco now.. sort of. I cranked up the intensity to a probably over exaggerated 500% just so I could really see the difference. This really shows the lighting/shadow issue. Also rendered at a better quality.

    I took a look the surfaces and display settings for all 4 lamp posts and everything is the same. Also, the things I hid are set to not-visible and cast shadows is off. I'm really stumped.

    The first image is from the left side of the bridge, the second is from the right. The same lights are brighter/darker no matter the angle.

    UberArea_500IntensityRight.jpg
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    UberArea_500Intensity.jpg
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    Post edited by Vaskania on
  • SzarkSzark Posts: 10,633
    edited July 2013

    I see it like I pointed out below??. Did you check that all of them have the same fall off and shadow settings?

    Also it there another rlight source in the scene

    IF they are all the same then try this. Select one of the light bulb surface on the opposite of the Dark Side and Copy the Surface (Options Box in the Surfaces Pane or Right Click on the surface in the Surfaces Pane) and Paste the material to all the opposite side bulbs. Or if you want the light to get over to the other side then reverse the above.

    Also make sure all the Glass surfaces are the same. Again use the copy and paste to make sure.

    UberArea_500Intensity_copy.jpg
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    Post edited by Szark on
  • VaskaniaVaskania Posts: 6,010
    edited July 2013

    There are no other lights in the scene, and yes all of the mats of each type are the same. I've been ctrl-clicking and editing them all at once (all bulbs, or all glass). I'll try the copy/paste and see what happens.

    Post edited by Vaskania on
  • SzarkSzark Posts: 10,633
    edited December 1969

    Yeah be carful when using Ctrl click to select a group to group adjust as I have found that sometimes applying Uber Surface and Area presets can give some wired results in DS4.5 + so I back it up with copy and paste which you can do with Ctrl click and group paste.

  • VaskaniaVaskania Posts: 6,010
    edited December 1969

    Welp, the copy/paste didn't change anything. It still looks the same as the last render.

  • SzarkSzark Posts: 10,633
    edited July 2013

    Are the lamps the same as in where the glass and dividers reside. Are they true mirrors of each other. I can't tell from the images.

    Has the lamp posts got a reflection map in the reflection channel, unlikey though, in the Surface Pane.

    You are using a proper cam and not prespective to render?

    The only other thing I can suggest is try again. But to make it easy Select one Lamp Post and "Save As" a material preset and check the Bulb and Glass surfaces. You then use that new preset on a newly loaded set. Then select all the Lamp Posts and apply the preset. Test render to see if that worked.

    If you want the same Camera Angle then you can select the camera and Save As a camera preset.

    Post edited by Szark on
  • VaskaniaVaskania Posts: 6,010
    edited December 1969

    About the mirroring, for this render I took the 2 left lamps and completely rotated them 180 degress on Y- same issue.

    I am using a regular cam with DOF off. For this render, I've moved it to be completely dead center between the left/right sides of the bridge, set it to 50mm, with a 1.8 f-stop (mimicking my 50mm prime), and set the focal distance between the two front lamp posts.

    The glass, bulb, and post all have the same diffuse texture, the glass and post have the same bump, the bulb has no bump. They're set to Metallic lighting model by default.

    For whatever reason, it seems like there's an invisible hierarchy from lamp to lamp (the columns they're sitting on though seem perfectly fine). It seems to lose intensity from the back right to the back left clockwise.

    UberArea_50mmcenter.jpg
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  • SzarkSzark Posts: 10,633
    edited December 1969

    Yeah I agree something strange is happening and I have never seen this before. I am sorry to say I am stumped.

  • VaskaniaVaskania Posts: 6,010
    edited December 1969

    That makes two of us. Once I can get back in the members forum I may post it there and let Jack take a look at it.

  • SzarkSzark Posts: 10,633
    edited July 2013

    I don't think this is down to the props. I am doing a little testing right now.

    Post edited by Szark on
  • VaskaniaVaskania Posts: 6,010
    edited December 1969

    KK. Just to test, I started a new scene using the original Preload rather than the one that comes with FW texture set. I get the same issue.

    I first changed the back left bulb/glass settings. Light works, shadows are fine, and it's illumination is bounced onto the lamp across from it, lighting it up.
    Then I edited the bulb/glass for the back right, it's light does not get bounced onto the back left lamp; however, the floor shadows do change.

    I still have no idea why the rear lights would be brighter than the front either when looking at the columns.

  • VaskaniaVaskania Posts: 6,010
    edited July 2013

    Scene shown with front/rear cameras. Both 50mm, 1.8 f-stop, focal distance between the two lamps. Is there a way to 'turn' the angle of the arealight on the bulb for #1 so it will aim at the front of #2 (the bulb isn't a separate object, just a matzone on the whole lamp)?

    Lights_Frontview.jpg
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    Lights_Backview.jpg
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    Post edited by Vaskania on
  • SzarkSzark Posts: 10,633
    edited July 2013

    I am getting the same with other props like this in DS3 and DS4.6. I tried leaving the cam still and I rotated the set 180% and got different illumination to before rotating, one side darker than the other. I tested it with spheres and that worked ok. I then tested by loading in freah lamp posts and placing them in the same place as the originals, deleted the originals and got the same inconsistencies in the lighting.

    Now I need to test more on other props using the Area base to illinimate the Props themselves.

    LampNew1DS32.jpg
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    LampNew1DS31.jpg
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    Post edited by Szark on
  • VaskaniaVaskania Posts: 6,010
    edited July 2013

    Thank you for confirming that I'm not crazy, or a complete idiot! LOL

    I never thought of rotating the prop itself. Hmm /edit- meh.. same crap different angle. lol

    Post edited by Vaskania on
  • SzarkSzark Posts: 10,633
    edited December 1969

    LOL Yeah no problem. I have changed my images above so you see the difference better.

    Once I have done some more testing to confirm this I need to make a bug report.

  • VaskaniaVaskania Posts: 6,010
    edited July 2013

    I wouldn't even know how to word that bug report other than, "stuff no workie!" lmfao
    Considering I have zero clue as to what the technical reasons are behind this.

    Post edited by Vaskania on
  • SzarkSzark Posts: 10,633
    edited December 1969

    Disconsolation http://www.daz3d.com/disconsolation
    As a work around try Area Spheres and scale as shown below. You can remove the texture and bump maps from the bulb and set Opacity to 0% and use the Area spheres as your light bulbs.
    Placed 14 Primitive Spheres and applied Area Light Base, resized the spheres in to a tall oblong shape via the scaling translations which resulted in even lighting.

    Next Area Light spheres in the same places as the above Spheres.

    As you can see the light is the same and even.

    I am still testing the light bulbs themselves as it may be a geometry issue after all but strange nevertheless.

    AreaSpehers.jpg
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    Spehers.jpg
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    SphereasLamp.jpg
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