Iray lighting for INDOOR use? Still confused.

RenderPretender

Hello -

After reading endlessly here and elsewhere about Iray lighting, I'm still searching for recommendations on lighting for areas that are ENCLOSED. I have tried various photometric solutions, and they're okay, but the issue seems to be the lack of an "ambient" light source that will provide even, non-directional "fill" for the other directional lights. HDR/Dome apparently can't penetrate enclusures, logically. Anyone have any reliable favorite solutions?

Thanks!

Daikatana

Have a few suggestions for you:

https://www.daz3d.com/iray-light-probe-kit

https://www.daz3d.com/architectural-lighting-rig-for-iray

https://www.daz3d.com/iray-ghost-light-kit

https://www.daz3d.com/iray-ghost-light-kit-2

 

 

Fishtales

Make the ceiling an Emissive and plug the diffuse map into the Emissive Channel. Set the temperature to 2750 for incandescent light up to 7500 for daylight fluorescent. Set the Lumen value up/down until you get the ambient light you want.

The other way is to set all the light bulbs to be Emissive and set each one to suit.

RenderPretender

Thanks for the suggestions indeed!

Griffin Avid

I like the probe kit option. Very easy to control the lighting and I think it's easier to set up than the Ghost Lights.

@Fishtales

What would the ceiling look like if it was included in the render? Would it glow? I have some sets where the windows are emissives and NOT made of any glass material. It would appear your suggestion is using that same system to make a "fake" light source inside the normally darkened room. BUT! There's no beams of light, like a godray. And the shadows are not too strong.

So, are you saying I make the ENTIRE ceiling a fake light source or am I picking a tile or make a 3Delight light/lamp an iray/shader/emissive?

Is that emissive native to Daz- regardless of the rendering engine used?

Fishtales

In Iray you can make any surface Emissive by making the colour white in the Emissive Channel. To get a light to be Emissive use the Iray Uber Shader on all the surfaces and then find the light bulb, if there is one, select it in the surface tab and set it to be Emissive then set the parameters for the required light. You can do the same with a candle if it has a flame and add the candle flame .jpg to the Colour Map for the Emissive channel.

The ceiling will glow in a render if it is bright enough but as it is only for ambient light the lumens can be balanced so that it isn't glowing bright but is still adding bounce light to the scene.

If the windows have a glass surface then select it in the surface tab and change the surface to Glass Thin using the glass thin shader. then put a distant light shining into the window set at say 10000 lumen at 4500 temperature then add a volume cube inside the room in front of the window then set the SSS to get the god rays.

There are a few examples in my render thread, see my signature for the link.

FirstBastion

Flat emmisive plane at ceiling or behind camera can provide ambient light.

Serene Night

I usually remove or hide the ceiling and use outdoor hdri or daylight indoors if I can.

I find emisssive lighting adds too much time to the render.

KindredArts

What's your actual issue here? Are you looking for more options because render speed is a serious issue, or are you looking and how to achieve hyper realistic indoor lighting? There are products to help in both areas, but you're not going to achieve quality and speed any time soon. As mentioned a couple of times in this thread, i do have a series of diffuse/ambient lighting products if speed is your issue. If hyper realism is your issue then you have to try and recreate real life lighting scenarios and bite the bullet on render time. I'd stay away from photometrics if realism is your goal too.

RenderPretender

Serene Night said:

I usually remove or hide the ceiling and use outdoor hdri or daylight indoors if I can.

I find emisssive lighting adds too much time to the render.

That's what I would do normally, but this particular environment prop only allows me to remove one wall, so if I want to get a camera angle that includes that wall, I'm pretty much screwed.

Serene Night

You can use a Iray section plane and remove part of the wall or roof There is also a free camera with section planes attached.

RenderPretender

Slightly unrelated question...

I have noticed that DAZ 4.10 is painfully slow going between tabs. Is there a way to adjust the workspace settings to speed things up?

Daikatana

I did this with the ghost light kit and it worked very nicely.  Just gotta put it basically touching the ceiling.  Then I got the light probe kit which works exactly as advertised.  The architectural light rig product also works wonderfully.  Neither of the three is “best”.  They all work differently and give different results in different set ups.  

FirstBastion said:

Flat emmisive plane at ceiling or behind camera can provide ambient light.

 

Twisty

I've been having the same trouble, some fantstic tips and recommendations here. Thanks everyone!! 

I've been using the Ghost lighting kit, but found it awkward at times. I'll give the probes a go too!

akmerlow

Sorry, don't know if i can ask in this thread, but i'd like to receive some advice on lighting indoors...

This 720p render, it finished itself at 10000 iterations (i should have set more?) after ~2 hours.. i think it was 20-25% status at that point :(

Besides question if i should have let it run much more, 'd like to ask advice about lighting this scene.. There are two lights here, one from window (i think it's emissive surface? mesh?) and another one is spotlight i put in front to light up character.

How can i make lighting more interesting? I hoped to see shadows and light from window itself too on desk and floor (like on 2nd pic of freebie https://sharecg.com/v/92797/gallery/21/DAZ-Studio/College-Dorm-House-Part-1-Requires-Part-2 ), but i don't know how to do. I tried reading threads about shadow capture (?) and it was something about adding matte setting to materials, but i didnt understand that at all. Also, about light on character itself. I want to have distinct light and shadow portions with visible borders, but i fail to do it too, as overall lighting looks very flat. Please, if you have any thoughts, i'll gladly listen! Thanks.

 

benniewoodell

What I would do is try to get that person's shadow off the wall as that looks unnatural and like you got a spotlight on them (which is what you said you do). There's a couple of ways to do it, one would be a soft light, not the spotlight but the other one that's a circle that name is eluding me right now or a ghost light, or stick the spotlight outside the window and blast it in which will give a nice edge light to the character. Then make a white plane and use it essentially as a bounce board and place it off camera facing the light but angled enough to use as a fill light on the person. It'll give a nice, soft light to them that will look great, we do this all the time on set. As for a shadow on the desk, I simply think the desk is too close to the wall, or the angle of the sun is not directly pointing towards the window. Again, try experimenting with a spotlight looking in through the window at different angles until you're casting the shadow you want, or try a wider desk. But I'm seeing now you also want the floor, that youll need to use a spotlight for or change the sun's placement.

marble

The sharp shadow from the spotlight can be softened by changing the geometry in the spotlight settings. Use a disc (not a point) and set the dimensions to 80x80 (or 100x100).

The Blurst of Times

If you want to use Spotlights rather than Emitters, another way to do the fill light is to parent your spot on top of the camera's eye.

Just parent the spot directly on the camera so that it/s 0/0/0 and 0/0/0.

This way, all the simulated photons are going the same way as the lens is looking... even though it's projecting directly forward from the point of the lens, there is no bounce-back and no shadow because the light and the lens are at the same singular point in space/time. (The light IS creating shadow, but the lens can't see it from the lens' perspective.)

FirstBastion

The key to lighting indoors is to add the same amount of light sources as in the real world. So rather than one spotlight,  you may need to add  15-20 small light sources.

A sunlight from the outside. Each of the lightbulbs on the fixtures are also small light sources,  and general daylight bouncing off the room walls creates a natural ambient light which softens the shadows.

The living room has 18-20 light

This bar has 40-50 small lights

 

outrider42

Just know that when using any mesh lights, the more complex geometry a mesh has can add make rendering take longer. Sometimes a lot longer. Using flat planes as a light source can be faster. So be mindful of what items you turn emmisive if rendering speed is a big concern. That's where the concept of ghost lights might come in handy, adding ghost lights at the windows to boost their light, or just outside the camera view can help speed up a render as well as light up a room.

The denoiser can potentially be very helpful indoors, too, depending on the situation.

akmerlow

Thank you much for advice and thoughts, will try out things.

FirstBastion said:

The key to lighting indoors is to add the same amount of light sources as in the real world. So rather than one spotlight,  you may need to add  15-20 small light sources.

But, if it's just a sunny day, so the only light is from opened window?

fastbike1

@akmerlow "But, if it's just a sunny day, so the only light is from opened window?"

You need to understand that the Studio render camera is like a real camera in that its dynamic range isn't nearly as good as a human eye. So an interior scene with just light from an outside source i.e. Sun/Sky or HDRI will not be nearly enough illumination.

Evenios

if you have any window the sunlight can pass through and light things up quite nice

just play with your rendering envirioment/tonemapping controls crank up the exposure indoors to have indirect lighting show up better you can also adjust the emessive lumincity of other lights in surface settings to comensate too if needed.

i find using indirect lighting via the sunlight through windows can be often the best and most realsitic way of lighting things!

 

 

AlmightyQUEST

You can have just the light from the outside, but you will need to adjust the exposure settings as you would with a camera (under render settings). However! This will also be really slow in iray, even with a decent graphics card, to have it render long enough to not be excessively grainy. Which is also like a camera in low lighting, just slower. This is why adding additional lights inside to simulate/boost the reflected light you would get in the room is recommended. You can then use an image editing application to adjust the image to be darker without losing details.

akmerlow

I'm slowly trying out your suggestions. I'll back up with pics (sorry for small size and huge noise, but they should give enough impression of what happens)

 

marble said:

The sharp shadow from the spotlight can be softened by changing the geometry in the spotlight settings. Use a disc (not a point) and set the dimensions to 80x80 (or 100x100).

Maybe it's too soft though? Shadow becomes barely visible.

The Blurst of Times said:

If you want to use Spotlights rather than Emitters, another way to do the fill light is to parent your spot on top of the camera's eye.

Just parent the spot directly on the camera so that it/s 0/0/0 and 0/0/0.

This way, all the simulated photons are going the same way as the lens is looking... even though it's projecting directly forward from the point of the lens, there is no bounce-back and no shadow because the light and the lens are at the same singular point in space/time. (The light IS creating shadow, but the lens can't see it from the lens' perspective.)

At first, i did something wrong. I manually typed translation and rotation values in spotlight that are the same as camera, and i got nothing, as spotlight ended up being somewhere in different place despite same values.

Then i decided just to create a new spot instead, and in create menu choose "copy selected item settings" so it worked as intended after that, being in same place as camera. So it gives additional light, but no shadows.

Though anyway such setup makes it look even more flat (aside from this circle of brightness on walls)? Here is an image with such spot, and on more brighter exposure

Same exposure without spotlight

 

benniewoodell said:

...stick the spotlight outside the window and blast it in which will give a nice edge light to the character. Then make a white plane and use it essentially as a bounce board and place it off camera facing the light but angled enough to use as a fill light on the person. It'll give a nice, soft light to them that will look great, we do this all the time on set...

I started with moving spotlight to outside. This is what i got, while environment intensity is 2 (in previous pics too)

With environment 1 there is more contrast (but too dark for such scene perhaps)

So i decided to leave environment at 1.5

Then i tried to do your suggested setup with plane. At first i didn't understand why i was not getting any effect, but then i've read that i should make plane emmisive through iray shaders, so i got this very warm light feeling the whole room. Is that what fill does? (My irl photography knowledge is limited)

I toyed around color temperature and got so many reds (and now i see that it works like ambient light right?)

Couldn't get blue tones through temperature settings of plane, only through changing colour of emission

Please say, if i got your explanation right and i'm on way.. or mistakes and all wrong?

Here is how setup looks currently (length of spotlight ray was increased by me when i thought it wasn't reaching):

Haven't toyed around other suggestions yet...

JonnyRay

Most 3D lighting is a balancing act from what is "real" and what you can live with speed wise. In the real world light bounces at ... well ... the speed of light. So strong sunlight shining through a window provides plenty of light to see with and usually (with minimal adjustments) can even produce decent photographs.

Unfortunately, all rendering engines take a bit longer to calculate how light is bouncing around a scene. Iray, in particular, seems to want to have more direct light on surfaces and less bouncing if you want it to converge in a decent time. That's why tricks like placing a low intensity ghost light over the ceiling or similar "bounce" lights around your main subject will get you to a finished image faster.

Those of us who came from the non-PBR world (like 3Delight) are well acquainted with many of these tricks because we didn't have "bouncing" lights. If we wanted a spotlight hitting the floor to reflect upward, we had to create light sources to simulate that.

Warning about Mesh Lights

As a couple of people have already mentioned, making a surface emissive is both a boon (you can actually have your light bulbs emitting light) and a potential concern because of geometry complexity. Consider the diagram below, looking down on a simple sphere with 8 divisions around the sphere and only 2 horizontal bands of faces. This would be a pretty low-poly object in a scene. But you can see there are 16 faces on the top half, 32 if you double it for a full sphere. To Iray, that means there are 32 additional lights in the scene when you make that surface emissive. Those are 32 sources to be considered and calculated in the scene. If you have 6 light bulbs with that geometry, you'd have 192 light sources that Iray has to calculate for.

While you're likely to get more realistic lighting by making the bulbs emissive, you may want to also consider if an alternative (like a ghost light (which typically only has 1 or at least just a few polygons) positioned in the same location and scaled down to approximate the light source) would be "good enough" for the lighting effect you're trying to achieve.

Mattymanx

On the Render Settings Tab, go to Environment.

Under Environment, you have Environment Intensity and Environment Map.

Both have values you can adjust to increase the output of lighting and HDRI maps.

I am not sure if Environment Intensity will also affect mesh lights if you increase it but it affects more than just the HDRI.

 

 

 

akmerlow

Thanks for tip, i only noticed intensity there.

Connatic

Serene Night mentioned Section Planes.

https://www.deviantart.com/slimmckenzie/journal/Tutorial-Iray-Section-Plane-Node-beginner-661286658

This tutorial gives a good overview.