indigo/blendigo 104 noob lighting tutorial?

[pxl666]

hi
this is my 1st attempt to do such a thing so pleez excuse me my mistakes.
for i had many problems understanding indigo's lighting system i want make something like a introduction for newbies. what i want to do is a set of simple scenes that wuld help understand lighting basics...its also for me to store things i could forget...

so heres my testscene setup - room with windows and glass and sun above and background plane to simulate real world. to add volume for meshes i use solidify selection script . there is a simple clouds texture UV mapped on the background plane. render settings are as follow - i have takem them from CoolColJ's thread about perfect render settigs.
in this render sun is almost straight above

heres 13min render


now u see sun is much lower - in blender sun position is irrelevant - the ray direction is important!

10 min render


and finally sun is lower than sea level

10 min render


now we have "midnight sun" requested by kram
setup


and render



now we'll play with emiters - these lights are made of flat surface - 8 faces round, and eff scale power

render


and same surfaces but with photometrics IES15

render

and some different ies prefs - from 1 - 5


now we have scene lit by meshlight - lampshade simulation - efficacy scale 20/20

render


and here u have scene where big background mesh stands for a lightsource - its UV textured mesh emitter





now weird things start to happen

this scene is lit by sun and emitters - but the emitters remained unchanged since last scene - and as u see they are simply too "weak" compared to sunlight


so...to get things right - ceiling lights are 200p/200eff and meshlight is 600/600...looks right now? i dont know why sun complicates things like that but...well...indigo is free!


next test is still about emitters and sun but now every emitter has different power settings:
ceiling light from left : 50/50 , 75/75 , 100/100 , 200/200 , 400/400
meshlights: left 200/200 right 600/600
understood??




and now i removed emitters and we'll play with sky turbidity -this is 5- hazy

and this is 2 - clear

not a big difference i must admit - we'll check exteriors later on...
thats all 4 today..hope i can edit this post tomorrow...cheers

okay im back on

exterior render - turbidity 2 - clear

and 5 - hazy


coming back to emitters - a little blackbody tests - different light temps



and PEAK emitters - these are a mystery to me...


then i tried some different colours


then UV textured my lampshades


and now im trying to get a grip about blending...im waiting for any of more experienced colleagues to explain me this phenomenon - shouldn't blended light be GREEN???


and finally - textured and blended emitter test


cya tomorrow - good night!!

now we have bumpmapped glass test with bacground colour lighting set to white


and same glass scene but instead of bumpmap i used displace - no tex/bump but hipoly meshes created of dispmap
setup

and render


now...here's interior with background lighting set to white

and exterior

with UV mapped skyplane

and with emitters - and again strange things started to happen - i didnt solve it yet (more gain??)

and here it is - same scene - lamps 20/17eff and background has 100gain


heres my quick&dirty test of "howto make a fire"


its UV mapped emitter - it still lacks alpha channel, but after post it could look pretty good

here we have 3 different camera settings - tonemapping is set to "camera"




a couple of DOF tests - note that i turned BIDIR off as it produced noiser images within a given rendertime (499s to get things quickly)





-----------------------------------------------------
this test i've done tryin to figure out best lampshade material
this my scene setup

emitter setup (bulb inside a lampshade)

and render


here u have material settings from left to right 1 to 5






hope u'll find this useful!!
-------------------------------------------------------------------------------

[ReinaDelSur]

I've just duplicated your little experiment and I must admit this is pretty awesome. Being a noob myself, it's actually really pleasant to have things explained step by step.

About the sun and its position... If I understand you correctly, the position of the sun is irrelevant when it comes to sky color (it being noon or sunset, that kind of stuff) but is it still important for the way shadows will be cast (or does Indigo somehow decide of everything)?

Another question I had was about the sun's energy and distance. Are they relevant or just disregarded once exported to Indigo?

Final question, if I place the sun right in the camera view, does it get rendered? Do I get some lens flares (or do I have to add this in post, which would only sound logical)?

Thanks for the tut, 'twas really good.

Ari ;o)

[ReinaDelSur]

Just after I'd posted my reply it seems you actually added some more stuff... So I guess I have more questions, the main being what's an IES file? (is it something like NKDATA for shaders only it defines accurate light properties?) Where do you get those files? Are they all compatible with Indigo? (I read somewhere around that not all nk files worked well with Indigo, that's why I'm asking)

Thx,

Ari ;o)

[pxl666]

as far as i know only the sunray is taken into consideration by blendigo.
ies files are found in indigo directory , possible only after update with new blendigo (i'm blender user).

looking forward to see ppls tests upon many various indigo issues
cheers!!

[Pinko5]

WOWWWWW Tnx!!!!!!!
Luca.

[Kram1032]

You have a mesh in the background, where the sun would be... How could the turbidity play any role? It only colours the sky - You'll see *real* differences, if you set unrealistic (not recommended) values: 1.5 will look darkblue or black, 20 will look kinda green

Then, you should add, that a "midnight sun" would give a violet sky, which is very unrealistic, but it happens due to the sky model. It's supposed to work correctly, between 0-12h

The sun position *never* is important, as Indigo assumes the sun, we see, and not any alien sun, out there, in the universe... Or our Sun, as seen on the Venus (if you ever see a sun, there xD) or what ever
The three angles (XYZ axis rotation) will define the direction of sunlight and everything.

The brightness of the sun also equals the correct brightness.
Lights of usual brightness react a bit unrealistic, as Indigo blacks (or greys) them out...

IES data is a special type of light data: It's very uncommon, that lights, especially when they're covered by bulbs or other shaped forms of glass, uniformly spread light in all directions.
These IES files have the amount of light saved in them, that glows in a certain direction. More realistic and in most cases also more interesting light sources are the result

Missing:

HDR lighting

Background lighting (in most cases not the best choice, but especially, if you combine it in an effective way with coloured meshlights, it could get interesting)

The improved but slow sun system (you'll need to tweak a bit in the IGS... And you for sure wont have reasonable results, after those 10-20 min renders...

Difference Efficiency/simple gain

Difference RGB/Blackbody/Peak

and maybe, a bit less related, stuff like bloom+glare/3 types of tonemapping/caustics/indirect caustics/participating media.
(You can also copy and paste and give credit to CoolColJ's awesome tests, they already have included most, what you could say, about the last three points + are an excellent guide to correctly set up the Indigo camera... )

One thing to add: CoolColJ first tested with MNCR of 10000 as his preferred value, but he later (dunno, when, but I think, it was the Indigo release, that showed caustics from underwater, when you look down on it, for the first time) switched back to Indigo's default value of 1000

Great Sum-up, so far, well done

[pxl666]

"The improved but slow sun system (you'll need to tweak a bit in the IGS... And you for sure wont have reasonable results, after those 10-20 min renders... "

hey kram - any more details???

[dougal2]

peak spectra:

there are 4 settings.

1. peak_min: this defines the center wavelength of the peak in the light spectrum, in units of nm
2. peak_width: this defines the width of the peak in the spectrum, in nm
3. peak_value: this defines the brightness/gain of the top of the peak
4. base_value: this defines the brightness/gain of wavelengths surrounding the peak

setting peak_value = base_value produces a flat spectrum = white light.

setting peak_value much greater than base_value produces coloured light, defined by where peak_min is in the spectrum.

[pxl666]

tut got updated - tell me what u think!

[Kram1032]

Ok, mom, I'll send you some threads about that sky model.
I hope, I find some

About blending: As Emitters aren't real Materials for Indigo, you can't blend them.
It's somewhat like that:
The piece of Wolfram is the Material.
The orangeish light, that gets emitted, is the Emitter.
The Wolfram itself could be mixed with, say, copper, but it certainly wouldn't be that good anymore, for emitting light.
The light itself can't be blended. Two different lightsources of different lightcolour could mix their colour, but not one and the same light with itself

Btw: Very nice update, but you didn't add the "midnight sun", yet...

Edit:
Ono didn't yet make the clouds freely accessible, but here, you can see the nice new sky system:
http://www.indigorenderer.com/joomla/fo ... ght=clouds

Here, you can see, what you'll need to handedit:
http://www.indigorenderer.com/joomla/fo ... &start=255
There's a button in blendigo, reading "extra atmospheric". It'll export a big sphere, an other big sphere-shell-sphere and a third big shell-sphere-shell-sphere.
The first is the earth, the second is the "close atmosphere" and the third the "far atmosphere".
It'll also export the "extra atmospheric" tag as "true".
You'll need to set it to false, in order to see the sky (DrBouvierLeduc was first, who found the actual difference, and Ono also explained it in that thread)

Here, you can see, what happens, if the extra atmospheric = true is used as it should be:
http://www.indigorenderer.com/joomla/in ... emId=20229
The earth sphere is textured, the moon sphere, added with correct size and distance and also textured.
The only things, added in post process, are the stars.

Besides Clouds, these things are missing:
Stars, according to your position
A correct moon (as you can see, this can be added by yourself)
In extremely far future, things like additional planets and other universe objects, or even a fully tweakable sun system, with multiple sun support (as most sun systems actually have twin suns, instead of singe suns, as we have) with including auto-planet-and-moon-creator and simulation of effects like gravitation lensing and stuff.......
Well, in very very far future, at least^^

[Vanessa07]

Very nice fire, I tried a few month ago... too hot for me

Are you going to test different camera "iso" and "shutter"?

[pxl666]

Very nice fire, I tried a few month ago... too hot for me

Are you going to test different camera "iso" and "shutter"?

very good idea - ill think bout it later!!

[impar]

hello there
i use ies files with other software, and didn't understand how you change the ies preferences in this tut, inside indigo and blender!!!
how do you change the power of the lamps for exemple.
you have 5 diferent settings for the same ies file????
thanks
Paulo

[pxl666]

ies parameters are constant unless u change the worldscale - this can affect ies power (light efficacy...)

[Kram1032]

changing the world scale poorly also changes other effects, which might look different.
(Many camera settings also are size-related)

The slower way, that therefore would allow a more similar final result, would be, to simply open the IES with any text editor and multiply the values inside with a constant value:
If you want to have a light, shining ten times brighter, simply multiply the values by 10