Tutorial Uber Area Lighting: The Basics

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  • SpottedKittySpottedKitty Posts: 7,232
    edited December 1969

    is that the "Angle" in the surface tab, The thing everyone seams to set to 180 or zero, when it should be kept at 89.90... or something somewhere else?

    Incidentally, that's not the proper alternate values for the Angles parameter. It's for helping to smooth curved surfaces — sometimes the mesh is built to do this properly, sometimes it needs a bit of help from this value. The default (and that's all it is, a starting default value, it doesn't have to be fixed at that) of 89.90 degrees is usually OK for smoothly curved organic shapes, but sharply angled edges can produce unwanted bulging effects when you render. If the usual starting value of 25 doesn't work to improve the render, try moving it up or down a few degrees at a time.
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,412
    edited November 2014

    Even for shaders going on flat geometry, hmmm. I did do some testing a while back with a shader set made for a desk lamp set, using it on floors and walls. The best value for true reflections and gloss, was the default.

    As far as I'm concerned, this is not a value to alter to make up for pathetic geometry choices when making surfaces.

    Agreed one or two degrees off of 89.90 for curved surfaces, not the extremes. It sends the render engine off into an endless ray-bounce loop, making renders take forever.
    http://www.daz3d.com/forums/viewreply/718855/
    I'm assuming you meant 45 not 25, lol.

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    Post edited by ZarconDeeGrissom on
  • SpottedKittySpottedKitty Posts: 7,232
    edited December 1969

    Agreed one or two degrees off of 89.90 for curved surfaces, not the extremes. It sends the render engine off into an endless ray-bounce loop, making renders take forever.
    http://www.daz3d.com/forums/viewreply/718855/
    I'm assuming you meant 45 not 25, lol.

    No, I did mean 25. The two pics you posted are actually exactly the sort of thing I use the reduced Angles value on — many spaceship models I have show the "bulging" problem in consistent places, which is almost always fixed with an altered Angles value; and I have that conservatory model, ditto. If I do try a value of 45, it usually only partly fixes the bulging.

    And FWIW, I don't think I've ever seen render time noticeably affected by the Angles value. Lighting type, yes, shaders, yes, but if a render bucket takes ages to process with an Angles value of 25, it also takes ages at the default value if nothing else is changed.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,412
    edited December 1969

    "O", well my sympathies that you have to resort to that, because a programer could not make a mesh without polygons twisting inside-out, and the modeler didn't know how to fix it. The reason I've decided I'm making my own ships from now on.

    For making a simple hexagonal cylinder appear more round, yes. For fixing a polygon pretzel mess, no.

    Here is that ship at 25 and zero. The mess is still there. The polygon mesh needs to be fixed, not turning the laws of light interactions inside out. I was going to make it a gold-plated model/prop, however forget that idea, lol.

    B.O.T.
    I will assume then that this is the 'Normal', that "tl155180" was referring to.

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  • Tramp GraphicsTramp Graphics Posts: 2,406
    edited December 1969

    a "normal" is the face of a polygon. Normals either face inwards or outwards, and they're all "supposed" to face the same way on a model. In order for an Uber Area light to work, the Normals need to be facing in the direction you want to light to project. In most cases, this means the normals must face out, but in the case of sky domes, for instance, the Normals must face inwards.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,412
    edited November 2014

    I thought that "Angle" was referring to this 'Normal', and thus the question? So what way is it facing when at 89.90, out or in?
    Pic from;
    http://en.wikipedia.org/wiki/Reflection_(physics)#Reflection_of_light
    ugh, the link is showing only partly, hmm.

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    Post edited by ZarconDeeGrissom on
  • Tramp GraphicsTramp Graphics Posts: 2,406
    edited November 2014

    I thought that "Angle" was referring to this 'Normal', and thus the question? So what way is it facing when at 89.90, out or in?
    Pic from;
    http://en.wikipedia.org/wiki/Reflection_(physics)#Reflection_of_light
    ugh, the link is showing only partly, hmm.
    Nope. That "angle" has nothing to do with it. The "normal" is the actual face of any given polygon. The full term is "Face Normal" or "Surface Normal".
    Post edited by Tramp Graphics on
  • prixatprixat Posts: 1,585
    edited November 2014

    The term 'normal' is a bit of archaic maths that just means 'at 90 degrees'

    If you think of coordinates X, Y and Z.
    X and Y make a plane and Z is normal to the plane.

    On a surface we use U, V and W.
    You're familiar with UV maps etc. they live on the surface.
    The W direction is normal to the UV surface and would be the depth or height in a bump map for example.

    By convention you can say the positive direction of W is the front and negative W is the back of a surface or individual polygon.
    The area lights are set up to emit in one direction only so 'normals have to face the right way'.

    That smoothing angle is something else... :-)

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

    Thanks folks I don't need to add anything more to what has been said already.

  • Richard HaseltineRichard Haseltine Posts: 97,381
    edited December 1969

    The smoothing angle isn't a "fix for bad geometry". With smoothing on the render will shade surfaces to disguise their sharp edges, which you generally want - the polygon will be darkened as it approaches an edge joining it to a polygon tilted further from the light, or lightened as it approaches a polygon titled more towards the light. The smoothing angle determines the point(edness) at which no such shading is applied. Most Poser and DS content will have bevelled edges to tame the smoothing, but not all and not all content made for other applications will.

  • KGKG Posts: 0
    edited December 1969

    Hi guys, sorry, I'm kind of lost, I can't find the "Default Base" / omUberAreaLight Shader mentioned
    in the beginning of this post, it is not in the Light Presets / omniFreaker

    Where can I find it ?, is this part of the free content or do I need to purchase something?

    Thank you

    J

  • fixmypcmikefixmypcmike Posts: 19,565
    edited December 1969

    JorgeMR said:
    Hi guys, sorry, I'm kind of lost, I can't find the "Default Base" / omUberAreaLight Shader mentioned
    in the beginning of this post, it is not in the Light Presets / omniFreaker

    Where can I find it ?, is this part of the free content or do I need to purchase something?

    Thank you

    J

    It's part of "Default Lights and Shaders for DAZ Studio", which is a separate download that's included with DAZ Studio.

  • KGKG Posts: 0
    edited December 2014

    Thanks for the quick reply fixmypcmike

    I just downloaded that bundle and there are many shaders, but Default Base / omUberAreaLight is not there

    I see in the pictures posted that in the Surface editor, the name of the shader is displayed as omUberAreaLight

    There is no shader named like that in my installation

    Thanks

    J

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

    It is under Daz Studio formats > My Daz3D Library > Light Presets > omniFreaker in the Content Library Pane (Not smart content). Once the base is applied to a surface then when that surface is selected it will then show up as omUberAreaLight in the Surfaces Pane. I just checked all this and it is still current for DS4.7.

  • KGKG Posts: 0
    edited December 1969

    I see! The UberAreaLightBase icon is the one,
    The thing is that it is marked as light, not as shader

    Thanks!

    J

  • SzarkSzark Posts: 10,634
    edited December 1969

    LOL Whilst a shader it is still technically a light and technically all lights in 3Delight are shaders

  • tl155180tl155180 Posts: 994
    edited December 1969

    Hey Szark,

    Sorry if this has already been covered somewhere in all this - can you please tell me if theres a way to remove the uber area light base from a surface once you've applied it and saved the scene (so can't use undo)? I applied it to a bunch of lights surfaces, then found that it slows the renders down horribly without really adding much to the scene, so I'd like to get rid of it... preferably without having to spend another few days setting up the scene from scratch again.

    Any ideas?

  • SzarkSzark Posts: 10,634
    edited December 1969

    A; if you have material presets in your library for those products then use those, or b; use the Daz Studio default surface preset under Shader Presets

  • tl155180tl155180 Posts: 994
    edited December 1969

    Wow - fast reply! Thanks Szark.

    Hmm, well I don't appear to have any presets Daz default shaders (or even a shader presets folder), so I guess its back to the drawing board with the default room materials then. Oh well. I'll have to be more careful using the UA base in future.

    Thanks for the suggestions.

  • fixmypcmikefixmypcmike Posts: 19,565
    edited December 1969

    Where are your UberSurface presets? Those are normally under Shader Presets.

  • tl155180tl155180 Posts: 994
    edited December 1969

    Where are your UberSurface presets? Those are normally under Shader Presets.

    Ah yes - found them. Thanks Mike.

    I didn't realise there was a folder for shader presets thats separate from the 'presets' and 'shader' folders. That seems a bit illogical to me, but there you go. Perhaps thats why I can never find anything in Content Manager lol.

  • tl155180tl155180 Posts: 994
    edited December 1969

    I seem to have another head-scratcher now with this same darn scene. For some reason uber area lights won't work in the scene anymore. I can load a brand new UA light plane, do nothing to it but move it around, and it will cast no light at all. It still renders in the scene as a white plane, but no light emits from it. All the other lights are still working as normal and if I load up a new scene and add an uber area light it works fine there as well.

    Have you ever come across this before?

  • SzarkSzark Posts: 10,634
    edited December 1969

    No I haven't had this issue before. Just out of interest are you sure the light plane is facing the right way.

  • tl155180tl155180 Posts: 994
    edited December 1969

    Szark said:
    No I haven't had this issue before. Just out of interest are you sure the light plane is facing the right way.

    Lol - yeah, I'm not gettin' caught out by that one again! :) I've also tried it in both directions, just in case I did something odd to the normals.

    Its weird. No new uber area lights I try to add to the scene will emit any light, yet the one I added to the surface of the LEDs previously (before all this happened) still emits a glow. I think I might have corrupted the save file somehow...

    I tried saving all the scene contents as a scene subset and loading them into a new scene, but I still can't add working UA lights. Tis very perplexing :/

    I think it might have happened when I loaded in a bunch of new UA lights and tried to select them all and change their surface settings as a group... It didn't seem to like that.

  • tl155180tl155180 Posts: 994
    edited December 1969

    Hmmm.. I did some experimenting with a new scene and it seems that adding an uber area base to a surface appears to render all of the free-floating uber area planes useless. For me anyway (I'm still using Daz 4.6). Is this just me then, or does it happen to others?

  • SzarkSzark Posts: 10,634
    edited February 2015

    I just got back from walking the dogs and am about to start cooking our evening meal. So after that I give this a try but I am using 4.7

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

    Think I might have figured it out actually, after much trial and error...

    I'm using the Aquatic Containment Facility by Stonemason and put uber area lights floating in the ceiling wells to represent light coming in from outside. Then I added uber area base lights to the LED_01 surfaces on the control panel to make them glow and thats when the ceiling UAs stopped working correctly. I've noticed though that the characters in the scene are still being lit by the ceiling UAs, but not the room itself.

    Kinda seems like adding uber area bases to any of the surfaces in the room causes the whole room to stop registering the free uber area planes. Very odd.

  • SzarkSzark Posts: 10,634
    edited December 1969

    If I had that structure I would ask for the duf scene file from you but I can't replicate that with the room I have tried. Also I recently redid the Area lights for Jack Tomalin's Library, for Jack, as they all had to be redone and I didn't have any issues with them either.

    What happens if you remove the Led light area light base, does the structure get lit then? As for Led's I would just use Ambient surface glow rather than actual light. Most indicator panel lights don't kick out that much light to have a big impact. Granted nice if the room is really lacking any major direct or ambient lighting.

  • tl155180tl155180 Posts: 994
    edited December 1969

    Yeah, if I undo the area light base on the LEDs, then the room starts reflecting the floating area lights again.

    I've changed it all now so that the room's light surfaces (LEDs, lights, vid screens etc) are all just ambient surface glow instead and theres no problem anymore. Sadly it means I can't add actual lighting to any of the lights in the structure to get that nice glowing effect, but at least the other free lights I'm using are working now.

    Maybe its just a quirk with that particular model.

  • SzarkSzark Posts: 10,634
    edited December 1969

    It would be nice if someone else could check it for you if they had that prop but from my experience, and I use these lights a lot, I have never had this happen. You can fake a nice glow effect in Photoshop.

    Set Ambient Strength and colour on the surfaces you want a physical glow for, (which Area lights won't give unless you are rendering through a volumetric camera)
    Turn all lights to 0% and Light to OFF.
    Render should be all black with only the glowing surfaces visible.
    Overlay this ambient light render pass over the main render.
    Set layer blend to Screen.
    Duplicate layer
    Apply Gaussian Blur which depends on the size of the glowing objects. Start with 5% - 10%
    Duplicate blurred layer apply the double the Gaussian Blur from the previous layer
    Duplicate and double the blur again
    Then adjust each layer's opacity to suit

    here is an example http://www.daz3d.com/forums/discussion/12654/#184048

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