Question on combining HDRI light source with other lights...

RenderPretender

Hello -

I sometimes like to use an HDRI as an ambient light source, while augmenting it with two or three point mesh lighting. However, when using a mesh key and fill, I'm always in a quandry as to where to focus the light source from the HDRI. Is there a best practice for what the directional relationship of the HDRI light and the mesh key light should be, since they're both really key lights by definition and can potentially wash out the subject?

Thanks!

MelissaGT

It really depends on the HDRI. There is no set formula. But I do use this lighting method for almost all of my work. HDRI is the primary light source with spots as needed for fill and hair lights. 

RenderPretender

MelissaGT said:

It really depends on the HDRI. There is no set formula. But I do use this lighting method for almost all of my work. HDRI is the primary light source with spots as needed for fill and hair lights. 

I agree. Sometimes I find that a high quality HDRI will suffice as a key, then I use a mesh fill and rim. That can eliminate any competition between the HDRI as a key, and a supplemtal key, which can be overkill.

RenderPretender

Attached is a raw five minute render of an uncomplicated piece I'm calling "Maven of the Mount" in concept. A high quality 8K HDRI is the only light source. I'm generally happy with it as all the assets are quality as well, and I think the lighting works, but supplemental lighting tends to blow out the whites in the scene. So in this case, the question is whether the environment light is all the piece needs. I'm leaning that way.

MelissaGT

RenderPretender said:

Attached is a raw five minute render of an uncomplicated piece I'm calling "Maven of the Mount" in concept. A high quality 8K HDRI is the only light source. I'm generally happy with it as all the assets are quality as well, and I think the lighting works, but supplemental lighting tends to blow out the whites in the scene. So in this case, the question is whether the environment light is all the piece needs. I'm leaning that way.

In my opinion I'd say you need to have a catch light in the eye as well as some sort of hairlight to bring the character out from the background. In addition, I would recommend turning on the in-render bloom filter to add some bloom to the scene (unless you plan to do that in post). I would also recommend turning down the strength of that HDRI as it looks overblown compared to the character. 

Here is an example of a white background that can easily get blown out and there is a spot off to the right (if I remember right) to help add a bit of catch to the eye and fill in shadows. Also bloom. Bloom adds so much to outdoor scenes, in my opinion. Without it, renders tend to look flat. Not a person, but you get the idea.  

Here is another exampe. This HDRI can easily get blown out but even here there is a spot off to one side as well as a hair light - 

Same HDRI as above only with a closeup portrait. Spot off to one side as well as a hair light - 

RenderPretender

MelissaGT said:

RenderPretender said:

Attached is a raw five minute render of an uncomplicated piece I'm calling "Maven of the Mount" in concept. A high quality 8K HDRI is the only light source. I'm generally happy with it as all the assets are quality as well, and I think the lighting works, but supplemental lighting tends to blow out the whites in the scene. So in this case, the question is whether the environment light is all the piece needs. I'm leaning that way.

In my opinion I'd say you need to have a catch light in the eye as well as some sort of hairlight to bring the character out from the background. In addition, I would recommend turning on the in-render bloom filter to add some bloom to the scene (unless you plan to do that in post). I would also recommend turning down the strength of that HDRI as it looks overblown compared to the character. 

Here is an example of a white background that can easily get blown out and there is a spot off to the right (if I remember right) to help add a bit of catch to the eye and fill in shadows. Also bloom. Bloom adds so much to outdoor scenes, in my opinion. Without it, renders tend to look flat. Not a person, but you get the idea.  

Here is another exampe. This HDRI can easily get blown out but even here there is a spot off to one side as well as a hair light - 

Same HDRI as above only with a closeup portrait. Spot off to one side as well as a hair light - 

 Thank you for the tips! I'll try them and see what I can come up with... maybe a rim light for her hair and a spot or mesh light for the catch. Lovely work, by the way.

RenderPretender

Btw, should I be turning down the dome HDRI Intensity, or fooling with Exposure? Seems that if I get ground prop snow detail, I lose the bright sunlight feel. Still need to add those other lights though.

MelissaGT

RenderPretender said:

Btw, should I be turning down the dome HDRI Intensity, or fooling with Exposure? Seems that if I get ground prop snow detail, I lose the bright sunlight feel. Still need to add those other lights though.

You can try lowering the dome intensity.  

Artini

MelissaGT said:

RenderPretender said:

Btw, should I be turning down the dome HDRI Intensity, or fooling with Exposure? Seems that if I get ground prop snow detail, I lose the bright sunlight feel. Still need to add those other lights though.

You can try lowering the dome intensity.  

Amazing images, as usual.

I have tried to make HDRIs myself, by importing to Daz Studio 360 degree panoramas rendered in Unity.

Unfortunately, I could only get 4K resolution (limitation of my Nvidia graphics card)

and these does not look great in Daz Studio.

 

RenderPretender

MelissaGT said:

RenderPretender said:

Btw, should I be turning down the dome HDRI Intensity, or fooling with Exposure? Seems that if I get ground prop snow detail, I ose the bright sunlight feel. Still need to add those other lights though.

You can try lowering the dome intensity.  

 I turned down the Dome/HDRI Intensity to 0.75 and added a rim light to illuminate her hair on the right, but it'll kill her ground shadow if it's much brighter than this. No bloom yet, and I can't sortout how to execute a catch light in a distance shot. Now I feel as if I neet a fill to compensate for the loss of light from lowering the HDRI Intensity.

RenderPretender

Next, I added a portrait mesh light to the left (Freja's right) to illuminate her eyes a bit. No fill or bloom yet as I'm trying to isolate the lighting effects for illustrative reasons.

RenderPretender

Hmmm... unfortumately, I now find myself spinning in the fabled maelstrom of "composing around the lights", trying to avoid geometry shadows being cast by them, and I find myself compromising on my original intent to accommodate all the lights supporting the environment light. Very frustrating. I'm using point lights, and the emitters are off, but there doesn't appear to be a way to regulate the geometry opacity (.0001) as with spots.