Daz Help with three point lighting and other techniques

[Oppai Auteur]

I've been working on my own game Old Friends and Public Transport for close to a year now, but even after all this time my grasp of lighting can't even be called amateur. Hell it would be a stretch to call myself an amateur dev in general

Pretty much every scene I've ever made is just light with a single light source, mostly just whatever HDRI I happen to have installed. On the very rare occasion I will make use of ghostlights if I need to add extra light, but my implementation of these isn't great either. In fact the only time I do use them is when the asset can't be changed to allow an HDRI to light it. At which point I just have to go with the final result, regardless of the quality

When ever I look up lighting or see it discussed on here on this forum, three point lighting is something that comes up quite a lot, along with many other techniques. I was wondering if any devs, or just anyone who uses Daz3d on here, with any amount of skill could maybe lay out for me how to actually implement this. Any time I've attempted to add lights to my scenes it never seems to make any difference to the renders. No matter how much I fiddled with settings nothing seems to change in the final result

So anyone willing to help this idiot out? lol

Cheers guys

 

[mickydoo]

I never use three point lights unless Im doing a glamour shot or something, they are not the best imo for indoor scenes for games, its too unnatural. I use an emission plane. This is rough and ready set up I just did, she is just inside a cube as it works best in an enclosed area.

Its just an ordinary plane, dunno how big it is but its about the feet distance apart on gen 8 models. In the surfaces tab you gotta change a few things.

Emission color to white
The luminance units I change to kcd/m^2
luminance to 1500 (more is brighter, less is darker)
cutout opacity just lest you make the plane invisible if its in the scene 1 is visible, 0 makes it invisible but it wont work so 0.001 makes it invisible but still works.

The plane is just here, moving it around and/or angling it creates a different lighting affect.

If you use ghost lights as well the light will be not so dark on her lower body.

 

[Xavster]

I have found that main aspect of lighting is to have a primary light source that is at higher intensity than any others. To prevent total blacks, it is preferable to have a secondary light source from an angle at least 90 degrees from the primary light, such that it provides some lighting of the shadows. The only other thing that I believe is necessary is that the lights make sense. Hence they come from somewhere and don't magically appear from nowhere.

There are a multitude of methods of achieving suitable lighting and dependent upon what you are trying to achieve, you should use different techniques. Hence for outdoor scene I don't really consider using anything other than a HDRI. Indoor scenes I used to use emissive light sources, however have been trending towards spotlights now. However I still use emissive surfaces on the props should they be appropriate.

At the end of the day, you are only really going to get better through trial and error. Hence spend time trying to perfect the lighting on the current image rather than moving onto the next. Sometimes it is better to move the props / characters in a scene than to change the lighting. Also often changing surfaces to increase or reduce roughness / reflectiveness / glossiness is sometimes required.

 

[Rich]

Let's face it - lighting is challenging. This is true for photographers and movie makers just as much for those of us using 3D software that tries to mimic real world light behavior.

Emissive planes and ghost lights can be useful, but frequently they don't nice shadows, and it's actually the shadows that make lighting look realistic. Not necessarily deep black ones - it's the subtle ones that our eyes are used to seeing.

In many cases, you can get reasonably good lighting by combining a spotlight and an HDRI. Have the spotlight hit the figure from somewhat above, and from an angle other than where the camera is aimed (frequently, above and to the left of the camera). Also, set the spotlight to be rectangular with an area maybe 20x20 or 30x30. The default spotlight uses a point source, which casts very harsh, unrealistic shadows. The HDRI then fills in the background and the parts of the figure that the spotlight doesn't illuminate. If this leaves parts of the figure on the other side of the spotlight too dark, you can add a second one on the other side.

These are two of the three lights in "three point lighting." The third light (traditionally) is from behind, and gives a slight "halo effect" on the figure. While useful in shots that are supposed to look like portraits, we don't see this effect in the real world that much, so you can usually omit that light.

Indoor shots are a lot harder to light. When I can, I frequently open up the ceiling to allow an external HDRI to come in - that can create some good effects when a spotlight or two is added. Or go the emissive plane/ghost light approach from above - you can always make one that's almost the size of the ceiling. This gives the "background light" we're used to seeing, which is actually the result of light sources bouncing all over the place.

Past that, practice, practice, practice...

 

[79flavors]

Someone posted this tutorial for creating a character portrait a while ago...

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It's very tailored to creating that specific portrait... but I'm guessing some of the lighting solution is transferable to other scenes.

There's also this tutorial video for lighting a night scene in Daz3D. I watched it a while ago and some of the lighting advice seemed very similar to the portrait tutorial.



I should probably mention that I've barely ever rendered anything - so my "expertise" is suspect at best. However, maybe one or both of these videos can at least nudge you in the right direction.

Edit: Or just YouTube search for "key, fill and rim lighting" or "3 point lighting" (not that I knew those names before watching the night scene video. Based on that, it seems like the world of photography and the world of Daz rendering are close enough for noobs like us.

 

[Oppai Auteur]

I appreciate you guys trying to help me out, but I don't think the first post really emphasizes how little of this I understand and the issues I have been having

@mickydoo - The problem I have with emission plane technique you laid out is I don't have the slightest clue what an emission plane is, or how to even set one up. I went through my Daz3d assets and the closest I had was a light plane I got at some point, but it didn't have the kind of settings you gave a screenshot of so I was unable to use it.

@Xavster - I usually only need the HDRI when doing outdoor scenes as well. It's mostly the indoor stuff I have a problem with, especially when I cant remove walls to let the HDRI in. I understand the concept of trial and error, but the whole reason I made this thread was that wasn't working for me because it was all error no learning, nothing I do seems to work. The built in Daz3D tutorials weren't much help either

@Rich - I've tried several times to add spotlights to scenes but it never seems to have any visible effect on my renders. I don't know if there is just something I'm not getting, but unlike for a lot of others I see on the forum, spotlights don't seem to work

@79flavors - Thanks, I'll check these out

 

[Xavster]

Since you are comfortable with HDRI's and struggling with indoor lighting, I would suggest you employ Iray Interior Camera V1.3 as linked below. It brings the lighting from an external HDRI through the walls of an indoor scene to light everything up.

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One of my previous series used this lighting tool as you can see in the links below:

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Note: Despite what it says on the interior camera download page, you can change frame widths and depth of field.

 

[mickydoo]

The emission plane is just a normal plane, up the top just click on create, new primitive, plane, and change its surface properties in surfaces tab like in my pic. The interior camera @Xavster mentioned I have used and is pretty good in some situations, but I personally try not to use it. i have found with it though, if you go to

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and look for something that say is a room in roughly the same hue as your scene you can get some good results, but like I say it's not my first choice. As @Rich mentioned you can make the plane the size of the ceiling, just lower the temperature of the light if need be, or an easier way, as long as the room is iray (you can convert it anyway) you can just make the the ceiling itself an emission plane. the only reason I do it my way is I am trying to make the character stand out as much as possible without making them too realistic for the room.

Edit - just read up more, you can use the geometry tool to remove walls and ceilings that are attached to everything else. If you need more info on that just ask, it's pretty easy but takes a little explaining.

 

[Rich]

I've tried several times to add spotlights to scenes but it never seems to have any visible effect on my renders. I don't know if there is just something I'm not getting, but unlike for a lot of others I see on the forum, spotlights don't seem to work

The default luminance value that Daz uses for the spotlights it creates is 1500, which is really, really stupidly low. You may need to crank that up a LOT to see anything. I can't think of the last spotlight of mine that was less than 10,000. I've commonly had ones up to 50,000-100,000, and, on a few occasions, up into the millions.

 

[Xavster]

For a simple room setup, these days I typically use a single spotlight on the roof in the center of the room with the following settings.
- Sphere source
- 20cm diameter (adjust to get different shadow edge sharpness)
- 180 degree lighting angle
- light intensity somewhere in the 100,000 to 1,000,000 range
- Render Emitter = off

You need to be somewhat careful when placing characters, however if you have characters on one side of the room and the camera on the the lighting should be acceptable.

I used to use emissive panes in the ceiling as @mickydoo mentions above, however it almost complete eliminates all shadows and make the image look quite artificial.