Tutorial: Using UberPoint Lights

adamr001adamr001 Posts: 22
edited February 2013 in Daz Studio Discussion

This is a revival of a tutorial from the old forums.

What are Point Lights?
Unlike Spot Lights and Distant Lights which are unidirectional (they shine line in one direction), Point Lights are omnidirectional (they shine light in a 360 degree globe). Think of a flashlight. You think of a beam of light, right? Now think of a bare light bulb... it's a sphere of light shining in almost every direction. In DAZ Studio, that's the difference between a Spot Light and a Point Light.

Why should I use them?
Well, how many times have you tried to light a fireplace or a lamp or anything that casts light in several directions at once? Sure, you could bundle up spot lights and adjust the beam width and try all sorts of things -or- you could just add a point light! Point Lights are easy to use and create accurate results!

Why Uber Points and not the built-in Point Lights?
Well, Uber Point Lights offer several advantages over the built-in point lights.
1)^^ Uber Point Lights offer Falloff Control - This allows you to control how far the light reaches without adjusting intensity.
2) Uber Point Lights offer support for image mapping. Allowing you to broadcast an image in 360 for environment effect (gel lighting).
3) The built-in Point Lights use an accurate decay model, but that decay begins instant and has no end (infinity) so they are "weak" (don't shine light very far) as well as being computationally expensive (the light has to be calculated to "infinity").

^^ Linear Point lights have since been added to DAZ Studio and they give you falloff control, but lack shadow color and gelmap capabilities.

Okay, so how do you use an Uber Point Light?
It's easy! Load it up, move it where you want it to be, setup your falloff and click render!

Wait, you want more than that? Laughing Okay... here goes!

Positioning:
I typically position an Uber Point Light (very) slightly offset from the object I want to be perceived as casting the light. So if you're talking about a light bulb hanging from the ceiling, I'd put the Uber Point about 1-5 cm below the geometry of the bulb. If it is for a lightbulb in a lamp, then between 1 and 5 cm above the bulb geometry, etc. Here's a tip, it doesn't always work, but it does often enough to warrant trying it first.... Open up the Align Tab (view > tabs > align). Select the Object in the Scene has the geometry for your lightbulb in it. Then, while holding the control key down, select the Uber Point you want to use. Now change the Align tab's X,Y,Z values to "Align Centers". Click Apply. Blamo! Now all you have to do it move the point light a short distance to get it position correctly above, below, to the side, etc. as appropriate. This can be a pretty big time saver when positioning point lights, but sometimes it'll only get you "close" and you'll still have a bit of work to do.

We'll go through the rest of the parameters in the order they appear.

Shadows Section:
Uber Points work almost exactly like every other type of light in DAZ Studio. The main difference is you cannot use Deep Shadow Maps with an Uber Point. You must either have no shadow or use Raytraced Shadows. This is true of any light with falloff.
* Shadow Type: Must be None or Raytraced.
* Shadow Softness: Allows for light bleed making the shadows edges soft/fuzzy.
* Shadow Bias: The distance, in centimeters, to shift shadows TOWARD the light source to prevent self shadowing. For larger scenes the default value is fine. For closeups, a smaller value will be required.
* Shadow Samples: Like all Uber lights, UberPoints override the default Shadow Samples value on the Render tab. The default of 4 is OK if you have a lot of OTHER lighting in your scene, but UberPoints are your primary light source, a higher value is recommended. 8 is generally the minimum I recommend for final quality renders, and 16 is what I generally use when UberPoints are the primary light source. I've gone as high as 32, but I don't recommend it.
* Shadow Color: Most often used in a greyscale fashion, it lets you control the color of the shadows produced by the light. You can add color for interesting sci-fi / fantasy effects though!
* Shadow Intensity: How "strong" or opaque the shadows are. At 100% the shadows produced will be 100% opaque obscuring the detail of what's behind them. Barring any other light source. That last bit is key and is why 3 point lighting with spotlights work as it does. You can lower the shadow intensity to "fake" this type of effect. Most often I leave it at 100% but I've been known to use it at 85 or 90% too. Rarely lower, but that's personal taste.


Next up is the Display Section:
All the parameters in here only affect the viewport. It's all pretty self-explanatory. The main consideration is that the sphere diameter is listed in meters instead of centimeters. I almost always ignore this section entirely.

Now to the Light section.
We've got two subsections, Basic and Falloff.

Light > Basic:
This is where the traditional meat and potatoes is. You're going to set your illumination type, intensity, intensity scale and color and color map (if any).

* Illumination Type:
* * On : Traditional mode, the light generates both Diffuse and Specular response.
* * Specular Only - The light only generates specular response on materials. This is a fun mode, if you want to control the color of the highlights uniformly in a scene. I use this mode most frequently with distant lights, but it applies here as well.
* * Diffuse Only - The light creates no specular response, but otherwise tints the scene and casts light and shadows normally.
* * Off - This is the same as hiding the light on the scene tab. It will cast no light and not be considered during rendering.
* * Intensity and Intensity scale: These two values cannot be separated. They're basically how bright your light is. You take intensity % and multiply it by intensity scale to get actual intensity. So 100% and 100% is 100%. But 50% and 50% is only 25%. Intensity scale allows you to bypass the 100% "limit" on the intensity slider, without disabling limits, so I suppose that's why it's done this way. For bonus points, disable limits on intensity anyway and set it to -100% and watch the fun (you'll need other lights in the scene).
* * Color is color. Yes, you can have black lights, it isn't the same as negative lights though. Negative lights are fun. (see intensity).
* * Color Map. You can attach a jpg issue (scale is 2w : 1h, e.g. 1024w by 512h) and those colors will be "broadcast" out from the light. Best used with color set to 255,255,255 for accurate translation of the color map. Useful for all kinds of things, but the built in "Torch" preset is a great example.

Now for the real fun, Falloff!
* * Falloff Active: Defaults to On. This attempts to replicate the way real light works. This is good. You can turn it off and see how the point light instantly "appears brighter". It's not though, it's just not being affected by decay (see below).
* * Falloff Start: The distance in Centimeters that the light should shine before beginning to decay.
* * Falloff End: The distance in Centimeters that the light should shine before it completely fails to illuminate.
* * Falloff Decay: The rate at which the light decays. There are three values
* * * * 0 : No Decay, makes the point light truly infinite.
* * * * 1 : Linear decay, predictable, but not realistic. An object twice as far from the light is half as bright.
* * * * 2 : Default - Modeled after how light actually behaves. An object twice as far from the light is 1/4 as bright.
* * Now, with THAT said, you can break the Falloff Decay rules quite handily by increasing the Falloff End. When the Falloff End is further out than the default mode would indicate, Falloff reverts to a linear mode but stretched across the entire distance from Falloff Start to Falloff End. This is my preferred method of using falloff as it is the most predictable and easiest to control even if it's not 100% accurate.


Here's a handy-dandy table of values in Centimeters converted for us poor Americans...
* * 2.54 cm = 1 inch
* * 30.48cm = 1 foot
* * 304.8cm = 10 feet
* * 914.4cm = 30 feet
* * 1,828.8cm = 60 feet
* * 2,743.2cm = 90 feet
* * 10,058.4cm = 330 feet

Setting your Falloff Start and End variables is a personal choice. It's entirely dependent upon the mood your trying to create and how bright you want your light source to appear. Yes, I said bright, which implies intensity, but it also implies how far the light will carry. You can have a dark light carry far in a dark scene... It typically start with values of 304.8cm for start and 914.4cm for end and adjust each up or down from there, but that's just me.

Anyway, I hope this helps beyond just defining again the terms used on the parameters tab.

I like to showoff this particular scene as an example of the Power of Uber Points. It was lit entirely with just four uber point lights. Can you see where each of them is? It should be obvious. :)

Post edited by adamr001 on

Comments

  • Joe CotterJoe Cotter Posts: 3,164
    edited February 2013

    adamr001 said:
    ...1) Uber Point Lights offer Falloff Control - This allows you to control how far the light reaches without adjusting intensity .... built-in Point Lights ... decay begins instant and has no end (infinity) so they are "weak" (don't shine light very far) as well as being computationally expensive (the light has to be calculated to "infinity")....

    Linear Point lights have falloff start and falloff end, or am I missing something? They don't have built in gels.

    Love the tutorials, ty for taking the time to do them :)

    Post edited by Joe Cotter on
  • SzarkSzark Posts: 10,208
    edited December 1969

    Gedd the Linear Point doesn't have many of the functions that the Uber Point has. It has no shadow colour, Gel and Decay setting.

    adam was there supposed to be an image posted with that above?

    Another thing I do is leave the Fall Off start value at 0 and just adjust the Fall Off end only, leaving the deacy at 2. This way the light reacts more like realistically

  • adamr001adamr001 Posts: 22
    edited December 1969

    Linear point lights were not available when the tutorial was originally written either. :)

    And yes, Szark, the copy and paste didn't bring over the URL. I'll go add it, thanks for catching that. LOL

  • SzarkSzark Posts: 10,208
    edited December 1969

    No worries I just love seeing your images and was intrigued to know which one it is.

  • adamr001adamr001 Posts: 22
    edited December 1969

    It's up there now... my "previous recorder holder" for largest scene... The new one blows it away though. Over 4M verts so far and I'm not finished. Single render, no layering. I'm crazy. :D

  • SzarkSzark Posts: 10,208
    edited February 2013

    We can be carzy together Adam. LOL I have no choice at the moment I have to do layers. I am borrowing an old P3 machine and DS3A just runs. :)

    Arr that image, very cool, I like that one.

    Look forward in seeing the new one

    Post edited by Szark on
  • adamr001adamr001 Posts: 22
    edited December 1969

    Thanks! I love pushing the limits of what DS can do. Right now it takes about 27GB of RAM to render the scene at 3840x2160. ;)

  • SzarkSzark Posts: 10,208
    edited December 1969

    Nods...yep 32 GB Ram (or more if I can afford it) I am aiming for, for my new workstation. I have never been able to do this as the boundries where limited by my machine.

  • wancowwancow Posts: 2,708
    edited December 1969

    trying to find these in the store and I canna find 'em :(

  • SzarkSzark Posts: 10,208
    edited December 1969

    Go to Shop by Vendor http://www.daz3d.com/omnifreaker and you wil find the link for Point Lights http://www.daz3d.com/uberpoint-light-shader-for-daz-studio

  • wancowwancow Posts: 2,708
    edited December 1969

    forgive me while I DROOL....
    I was confused when I saw "Shader"

  • adamr001adamr001 Posts: 22
    edited December 1969

    Yeah, sorry, I should've linked them too. Man I'm off my game today! LOL

  • SzarkSzark Posts: 10,208
    edited December 1969

    I love these lights so much, great when used with AOA's Atmosphereic Cameras, same with Spot lights too

  • wancowwancow Posts: 2,708
    edited December 1969

    must buy when I have money... no special price for PC :(

  • Joe CotterJoe Cotter Posts: 3,164
    edited December 1969

    I actually have the uberlights, but thought I'd point the decay out for anyone who can't afford them yet. The Uber are definitely more full featured, but linear offers some flexibility over a basic spot.

    Szark said:
    Gedd the Linear Point doesn't have many of the functions that the Uber Point has. It has no shadow colour, Gel and Decay setting.

    adam was there supposed to be an image posted with that above?

    Another thing I do is leave the Fall Off start value at 0 and just adjust the Fall Off end only, leaving the deacy at 2. This way the light reacts more like realistically

  • adamr001adamr001 Posts: 22
    edited December 1969

    Yup, thanks Gedd. I originally wrote the tutorial before we had the Linear Point Lights. I've added a note to the initial post that indicates that Linear Point Lights do have fall off. :)

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