Tutorial Uber Area Lighting: The Basics

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  • Joe CotterJoe Cotter Posts: 3,234
    edited December 2016

    Actually, candlelight would be a point light as would a light bulb. It appears you are confusing light temperature with light distribution. The type of light describes light distribution not it's temperature or intensity, which are set separately.

    Basic light types in 3D graphics (any software) are point lights; which distribute in a 360 degree fashion from a single point, spot lights; which distribute light in a cone from the light source where the cone angle and sharpness of fallof are controllable settings, distant lights such as a sun light which is at an infinate (for our purposes) distance which therefore have all light rays running in a single parallel direction but infinately wide (as sunlight/moonlight would) and a hemi light, which also has parallel rays but from a nearby point similar to point and spot lights. The hemi light was the closes thing we had to a softbox so they were often used in more advanced lighting in the past.

    Then came the mesh light. The mesh light can eminate light from the surface of any mesh, but is most often a plane or disk and is used like a softbox in photography. Just like how a photographer will often defer to a softbox or reflector (like a softer softbox) over a point light or spot light for lighting, mesh lights will often also give superior results in most lighting conditions, other then the ambient light of course which was previously often represented by a dome light but is now most often represented by an HDRi image.

    Note, all lights other then distant lights have a falloff paramater that can be adjusted. Also, most real world lights don't distribute light evenly whereas these compter generated lights do. If one wants to emulate the uneven distrubution pattern of a real world light we can using IES lighting profiles. However, this is really most usefull if doing advanced architectural type rendering. For most of us, the effort to set up IES lights won't make a significant enough difference to warrant the time. As IES lights become more 1 button type of lighting this might change, depending on the type of renders we do.

    All of this is an extension on what mage and totte said, which by the nature of the question seemed might be useful.

    At studios like Pixar or ILM, there are people who's whole career is just lighting, so understanding the intricacies of how all of these different types of light plays out to create a scene and atmosphere gets into some pretty deep waters, and a full course on lighting would be just a starting point, but these concepts are at the heart of it.

    Post edited by Joe Cotter on
  • Joe CotterJoe Cotter Posts: 3,234

    Forgot to mention, Uber lights are some of the best lights one could use in 3DLight (a version of Disney's Renderman render engine.) They don't work in IRay. IRay has their own lights. If you are rendering in 3DLight, not only are these good lights, but there are many light setups in the store which are based on Uber lights which save much of the hassle of trying to figure out how to set up the lights for good results. Just like a photographer will have different lighting setups for different photography situations, we can purchase pre setup lighting rigs which work towards a given lighting situation. If we render studio lighting in one situation and outdoor in another, these will often be different products.

    In summary, if you are looking for pre setup lighting for 3DLight renders, you might want to search the store for lighting solutions based on Uber lights.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,380
    edited December 2016
    Gedd said:

    Forgot to mention, Uber lights are some of the best lights one could use in 3DLight (a version of Disney's Renderman render engine.) They don't work in IRay. IRay has their own lights. If you are rendering in 3DLight, not only are these good lights, but there are many light setups in the store which are based on Uber lights which save much of the hassle of trying to figure out how to set up the lights for good results. Just like a photographer will have different lighting setups for different photography situations, we can purchase pre setup lighting rigs which work towards a given lighting situation. If we render studio lighting in one situation and outdoor in another, these will often be different products.

    In summary, if you are looking for pre setup lighting for 3DLight renders, you might want to search the store for lighting solutions based on Uber lights.

    Or give a particular test chamber a try (It's free, lightweight, and a good starting point).

    http://zarcondeegrissom.deviantart.com/art/ZdgTestChamber-v2-2-UE2-for-Daz-Studio-543097364

    or

    http://www.sharecg.com/v/81375/browse/21/DAZ-Studio/ZdgTestChamber-v2.2-UE2-for-Daz-Studio

    And don't be afraid to move the lights around. Just because I often start there, dose not imply I also end up there.

    TestChamber_Parts_UberAreaLights_Lbl1.png
    299 x 440 - 14K
    Post edited by ZarconDeeGrissom on
  • Light presets in DAZ Studio, more often than not, require a lot of work to get the effects I want. For that reason I use them in less than 1% of my renders. I prefer to create my own lighting, because I already know what I wish to achieve with them, and I have a lot of success with that way of doing things. You can say the work is comparable to that of working with presets, but in my case that is not true. When I setup a scene, I already know how I want it to look most of the time, and I know how to use my own light creations to achieve that aspect of it.

    One type of lighting that has not been mentioned is IBL, which can be used in DAZ Studio. It is similar to HDRI lighting, but the difference is the way it works. An image is used as a filter through which a single light source's light passes. The effect is to give that uneven lighting look to a scene. A good example would be what is known as caustic lighting, similar to what one would see at the bottom of a real world swimming pool. In DAZ Studio an image that has a caustic like pattern is used for stills and an animated image filter is used for animations. Caustic lighting is great for underwater scenes.

    One thing Bryce does that I have not seen in DAZ Studio is volumetric materials. So to get realistic looking haze effects, one must use multiple 2D planes that have the haze image pasted onto them. Why is this relevant to lighting? Because light must be able to pass through all of the planes to get the illusion of distance. In Bryce the haze and fog as well as 3D cloud materials are volumetric materials, meaning the material fills the object it is applied to. Now I don't know if the Iray render engine can do volumetrics, but 3Delight to my knowledge does not. For a 32 bit application that has not seen an upgrade in more than 5 years, Bryce is still a relevant art program, and it is one of my top programs in my collection. I think it would be awesome if DAZ Studio could actually incorporate Bryce 7.1 into its toolbox, including the render system it employs.

  • Gedd said:

     3DLight (a version of Disney's Renderman render engine.)

    I'm afraid 3Delight is not a "version" of Renderman, it's what they call a "Renderman-compliant" renderer. It means it can do all the things described in the RiSpec (and then some). The developers of 3Delight are a company called DNA Research, and they are a completely different entity, not affiliated with Disney/Pixar at all.

     

  • Now I don't know if the Iray render engine can do volumetrics, but 3Delight to my knowledge does not.

    They both can. Iray Uber material comes with a built-in option for it. To activate volumetrics in 3Delight, you need to use a shader like AoA's atmospheric cameras.

  • Joe CotterJoe Cotter Posts: 3,234
    Gedd said:

     3DLight (a version of Disney's Renderman render engine.)

    I'm afraid 3Delight is not a "version" of Renderman, it's what they call a "Renderman-compliant" renderer. It means it can do all the things described in the RiSpec (and then some). The developers of 3Delight are a company called DNA Research, and they are a completely different entity, not affiliated with Disney/Pixar at all.

     

    While that is true, I was trying to stay relatively close to the level of the question asked while at the same time filling in some fundamental concepts. The difference wasn't important enough I felt to delve into. Rather, it would by going into unnecessary detail for the level of the question, only confuse the matter.

  • Now I don't know if the Iray render engine can do volumetrics, but 3Delight to my knowledge does not.

    They both can. Iray Uber material comes with a built-in option for it. To activate volumetrics in 3Delight, you need to use a shader like AoA's atmospheric cameras.

    Not even sure if I have that. I'll look it up!

  • Gedd said:
    Gedd said:

     3DLight (a version of Disney's Renderman render engine.)

    I'm afraid 3Delight is not a "version" of Renderman, it's what they call a "Renderman-compliant" renderer. It means it can do all the things described in the RiSpec (and then some). The developers of 3Delight are a company called DNA Research, and they are a completely different entity, not affiliated with Disney/Pixar at all.

     

    While that is true, I was trying to stay relatively close to the level of the question asked while at the same time filling in some fundamental concepts. The difference wasn't important enough I felt to delve into. Rather, it would by going into unnecessary detail for the level of the question, only confuse the matter.

    Not looking to get confused here, that's for sure. These threads do tend to get like that!

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,380
    edited December 2016

    Agreed, lets not confuse things, as even I was not sure. Many posts and articles had me not sure if 3delight was renderman, renderman was a part of 3delight, they shared code or just not sure what was what at times. Nobody wrights in a way that confuses ILM's Sabre as something else, lol. I think I got a general idea of what 3delight vs renderman is now,  mostly.   3delight can comprehend renderman shader script language  but they are not the same program, or something like that.

    Post edited by ZarconDeeGrissom on
  • Joe CotterJoe Cotter Posts: 3,234

    Well Mustakettu85 is correct. It's just that for most of the people here the difference is of little concern.

  • Gedd said:

    Well Mustakettu85 is correct. It's just that for most of the people here the difference is of little concern.

    Still, misleading them regarding _facts_ doesn't seem to be a particularly enlightening option.

    // signed: Kettu, forum's resident killjoy, nitpicker and factchecker //

  • mjc1016mjc1016 Posts: 15,001
    Gedd said:

    Well Mustakettu85 is correct. It's just that for most of the people here the difference is of little concern.

    Still, misleading them regarding _facts_ doesn't seem to be a particularly enlightening option.

    // signed: Kettu, forum's resident killjoy, nitpicker and factchecker //

    And crazy RSL code-monkey...

  • Hey guys, let's not get into a dispute here. Let's leave our egos out of this and discuss the subject at hand please.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,380
    edited December 2016

    Yea, I'm confused enough with some things, especially before coffee in the morning.  I don't 'Think' there is a how-to floating around on the environment HDRI sphere-thing (Sky-dome light) for 3delight, I'll look around as I have my first cup of coffee.

    3delight as implemented in daz studio, dose not inherently do ambient light without a 'shader' to do that, or other trickery.

    There is a thing in the full version of 3delight that supposedly (I've never seen it) can do ambient light, there is just no interface in Daz Studio to use that feature.

    You can get close with spot lights (The photometric lights AKA menu lights may have replaced them, I need to check that) and Uber Area lights (this thread). I think something like UE2 (UberEnvironment 2) was mentioned as a possibility for lighting, There is a great thread overview of it here (all the links in the first post, are just links to posts in that thread. Just read and scroll, ignore the links). UE2 dose a few things, so I hesitate in saying it is 'Just' a shader for mimicking ambient light (I'm a little hazy about everything it dose).

    Trickery for lights bouncing off walls... like in this photograph.

    I'll need to find the buttons for that. It involves placing a second light to cast light the direction it would bounce off the wall (behind the wall), and set the wall to "Not cast shadows" on that second light.

    Post edited by ZarconDeeGrissom on
  • Joe CotterJoe Cotter Posts: 3,234
    edited December 2016

    Acutally, for ambient light, use a distant light for sun or moon. Since the distant light has parallel rays that extend infinitely it will generate the ambient light type of setting you are thinking of. Other light types will not, except in smaller spaces when mesh lights can basically perform the same depending on the situation. The distant light is also the more technically correct light, as outdoors it would be coming from sun/moon (and any manmade lights in the environment) and indoors, it comes from bounce light of some type, mostly sun/moon coming in from outdoors and any bounce light from other sources.

    I thought there was a sun/sky type light in DAZ for 3DLight but I'm not seeing it and haven't really used 3DLight in a while, but the infinite light will work otherwise.

    Also, I'm not sure if this is what you are trying to do but lights in 3DLight can be set to not cast shadows. This is commonly done to place point lights or other lights to fill in ambient light effects in areas of the scene.

     

    Post edited by Joe Cotter on
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,380
    edited December 2016

    I think it may be confused with another effect that sort of ruins scenes, because I've never figured out how to turn it off (the fire background here for example). It just sort of stay there regardless of what direction you look in render, that's not a good skydome to work with some stuff, lol.

    And I keep reading about a sky-dome like light, so it may possibly exist (where and for what 3delight interface is the question).

    Here I tried the First Light set for the first time, and it dose have many 'Distant lights' for the sky and other stuff. I opted to just leave the sun active from 'First light' and use the test-chamber UE2 and soft-boxes (Uber area lights) for ambient. It really looks like more is emanating from the skydome in First light then just the sun 'Distant light', so I'm not sure (Scratching head).

    Caveat with Distant lights. Many use them and turn off shadows on the lights in there products, unaware of what that dose to Subsurface Scattering and Velvet on many figures (Sometimes it produces a leopard skin look, other times it's just a strange glow everywhere, lol).

    Post edited by ZarconDeeGrissom on
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,380
    edited December 2016
    Gedd said:
    (snip)

    Also, I'm not sure if this is what you are trying to do but lights in 3DLight can be set to not cast shadows. This is commonly done to place point lights or other lights to fill in ambient light effects in areas of the scene.

    Na, in that mirror pillar test, the light should have reflected off the pillar back to the ground plane similar to what was in the photograph of a mechanics mirror illuminated by my stove hood light at an angle. It's a tad more refined then just light bouncing off a broad wall everywhere, and shows the single biggest limitation of the Daz Studio to 3delight, ah, I don't even know what to call it, something.

    Most other situations, there are 'Many' simple ways to get around that (light will not reflect off one surface to illuminate another surface, thing).

    Post edited by ZarconDeeGrissom on
  • Joe CotterJoe Cotter Posts: 3,234
    edited December 2016

    Bounce light doesn't just bounce off everywhere, it bounces at an angle incident to the incoming light beams, disrupted by the perturbations (noise) of the surface. When it does so, it will be tinted by the surface it bounces off of. So it's not more refined then bounce light, it's that bounce light is more refined then random distribution of the light bounced off of a surface. The reason that the illumination is so pronounced in a single direction in the case of the mechanics mirror you mentioned is that the surface is very uniform so that the reflected light rays mostly line up into a uniform incident angle relative to the incoming light.

    Post edited by Joe Cotter on
  • Hey guys, let's not get into a dispute here. Let's leave our egos out of this and discuss the subject at hand please.

    The subject at hand was area lights originally =)


    Gedd said:
    (snip)

    Also, I'm not sure if this is what you are trying to do but lights in 3DLight can be set to not cast shadows. This is commonly done to place point lights or other lights to fill in ambient light effects in areas of the scene.

    Na, in that mirror pillar test, the light should have reflected off the pillar back to the ground plane similar to what was in the photograph of a mechanics mirror illuminated by my stove hood light at an angle. It's a tad more refined then just light bouncing off a broad wall everywhere, and shows the single biggest limitation of the Daz Studio to 3delight, ah, I don't even know what to call it, something.

    A tad more "specialised" would probably be a better way of describing this - as Gedd says, in real world physics, this sort of thing is a subset of general light bounce.

    In CG, it's called "specular-to-diffuse light transport". I could go on about the reasons why it's considered on its own... but does anyone want to hear it?

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