I’ve been under the weather for several days, which hasn’t made it easy to be creative. But I was able to set up some scenes in DAZ Studio 4.7 Pro and let them render. I’ve been curious about the effects of different lighting in digital art, not only with regards to how lighting affects appearance but also rendering speed. I spent my down time running some experiments and will share them with you, complete with visuals, in the post that follows.
I set up a scene with a bunch of different lights. I used lights from a couple of professionally-created packages I licensed from the DAZ store: Set the Mood and Advanced D.I.Y Portrait Lights for DS4.
The mood lights consist of spot lights and distant lights, and come with a camera and something referred to as the “mood cube.”
The portrait lights are meant, as the name suggests, for close-up portraits. Amongst other lights, they include an ambient light and a specular light. These terms describing lights are all self-explanatory at a fundamental level except perhaps “specular” light, which is basically a light for bringing out shiny highlights, as you’ll see.
The images resulting from my experimentation are displayed and discussed below. Click one to see a larger version, and use your browser’s Back button to return to this post.
Legalese: All images in this post are copyrighted ©2014 by Eposic. All Rights Reserved. All these images were rendered using DAZ Studio 4.7 Pro, with no postwork (i.e., no touch up in a 2D graphics editing program) except as noted for Image #9.
As you might guess because I’m experimenting, I’m not an expert on lighting. I don’t understand all the different settings for all the different lights in DAZ Studio. So I use products such as the ones mentioned above, combining them or tweaking their settings to see what happens. It can produce more interesting results quicker than fiddling with settings on the basic lights provided in the DAZ software. Reading and viewing training material helps, but there’s a LOT to know about the subject. Having a good starting point helps tremendously.
When I started this particular scene, I had the idea for a hazy effect in the background, so that was the impetus for using the Set the Mood product. The hazy effect is brought about not by the lights as much as the mood cube, which I didn’t realize when I first started this experiment. I only knew what the product description said and how the promotional images looked. So I loaded in a hallway prop, a spooky girl figure and a light/camera set from Set the Mood. The hallway prop came with unlit candles on the walls and I thought it would be nice for them to be lit in my scene, so I added flames and point lights to the tops of the candles. Then, thought I, why not see how the portrait lights might help highlight the girl figure, so I loaded an ambient light and a specular light from the portrait light set. At this point, I had everything loaded in the scene. I situated everything where I wanted it. I reduced the intensity of some of the lights, since I was going for a darker look as opposed to a normal portrait. It was time to render.
With all those lights loaded and turned on, the render took 2 hours. Here’s the result:
Image #1, All Lights On – Rendering Time: 2 Hours
A two-hour rendering time might seem long, but I’ve set up other renders that took five hours or more to complete. I usually let those renders run overnight. Still, I think anyone would agree the shorter the rendering time, the better, especially if it still results in a good quality image. Since lights are often a big factor when it comes to rendering time, I decided to turn off the ambient light, which I’d set to a fairly low intensity anyway. I made no other change to the scene. I was shocked by the resulting rendering time. The image was darker, since it had less light. I preferred the first image, but for the difference in rendering time, I could almost live with the second one.
Image #2, Ambient Light Off – Rendering Time: Just Over 1 Minute
I’ve used ambient lights in other renders that didn’t take hours. Something in the scene was combining with the ambient light in a way that slowed down the render. Was it maybe the mood lights? I turned off the mood lights and turned the ambient light back on. This is what happened:
Image #3, Mood Lights Off – Rendering Time: 1 Hour 30 Minutes
The render still took over an hour. I wanted a dark image, but not that dark. Maybe the problem was the point lights I’d added at the tops of the wall candles. I turned on the mood lights, turned off the point lights and started rendering. I could see after about fifteen minutes that this setup was going to take close to an hour and a half like the previous one. No longer in a patient mood, I canceled the render, so I don’t have an image to show you. Since I had the candle point lights off, I turned the ambient light off and the mood lights on and started that render. As I expected, it didn’t take long to finish.
Image #4, Ambient Light Off, Candle Point Lights Off – Rendering Time: Just Over 1 Minute
There are still these little flames atop the candles, you notice, but they aren’t shedding light. Compared to Image #2, which also has the ambient light off but the point lights on, the rendering time is about the same. The visual difference might be subtle, but I suspect some people will prefer the candle point lights on while others will prefer them off. I prefer them on. So I prefer Image #2 over Image #4. Which of those two do you prefer?
At this point, it was obvious that something in the scene other than lights was interacting with the ambient light to slow down the rendering. I was pretty sure it wasn’t the girl figure or the hallway, which meant I was overlooking something I’d loaded when I loaded the lights. It was then I took notice of the mood cube. I turned off the mood cube and turned on all the lights. The result:
Image #5, All Lights On, Mood Cube Off – Rendering Time: 5 Minutes
Ah ha. I’d found the culprit. The mood cube didn’t want to play well with the ambient light. Digital artists who have used 3D rendering software more than I have might have known better. It was one of those eureka moments for me. Now I know that if I’m going to use a volume effect like haze, I’m probably in for a longer render time if I also use an ambient light. I don’t completely understand why, but understanding the why is not as important to me at this time as knowing the what.
You can see the tradeoffs in the images. Images #1-#4 all have the hazy effect in the background while image #5 doesn’t. Images #1 and #5 are set up exactly the same except for the presence of the mood cube in #1. To me it makes for a drastic difference that gives the girl more light, even though the haze is behind her. Moreover, one of my initial desires for the image was to have the hazy background. If I don’t lose the haze, I’m stuck with either a rendering time of over an hour or leaving out the ambient light. Another alternative might exist that would allow me to keep both the ambient light and the mood cube but still have a relatively low rendering time, if only I understood all of the settings in DAZ Studio. Maybe eventually some day.
Some people might prefer the image without the haze. If they also preferred the point lights turned off for the wall candles, the rendering time isn’t any different than when the point lights are on. The image for them would look like this:
Image #6, Candle Point Lights Off, Mood Cube Off – Rendering Time: 5 Minutes
Compare Image #5 to #6. Again, I prefer the point lights on, as in #5. Which do you prefer?
Turning the point lights back on, I decided to run the scene with the mood cube and ambient light both off, but everything else turned on. I wouldn’t get any haze, but I wanted to compare this result with Image #5, to better see the effects of the ambient light. It wouldn’t take long to render.
Image #7, Ambient Light and Mood Cube Off – Rendering Time: 30 Seconds
Yeah, it renders fast. But it’s so dark.
Compare Image #7 to #2. They’re both the same image, except with the mood cube turned on in #2 and off in #7. As I mentioned about Images #1 and #5, the haze behind the girl figure gives the girl more light somehow. Perhaps it’s an illusion, but the light of the hazy background definitely gives contrast to the girl figure.
I mentioned near the beginning of this post about a specular light. Through all of the experiments above, I had the specular light on. Go back real quick and look at Image #2 again. For Image #8, I used the same setup as for Image #2, but with the specular light turned off. Now you can see what a specular light does for an image.
Image #8, Ambient and Specular Lights Off – Rendering Time: Just Over 1 Minute
Earlier I mentioned that specular lights bring out shiny highlights. As you can see here, the sheen is gone from the girl figure’s lips, eyes and skin. But you’ll also notice the haze isn’t so bright either. The specular light gives the haze a real glow. For this particular project, I like the glow. In other projects, haze without a glow might be more suitable.
You can see how difficult it can be to get the lighting just right in a scene. There are all these different lights that have all these different effects. Then there are a multitude of settings for each type of light. Start throwing in volume effects like the haze, and you’re playing with so many variables, you can’t try them all.
I have been reading and viewing some training material. When it comes to lighting, some of the best training I’ve found is from Dreamlight 3D’s Basic 3D Training site. Val Cameron is the mastermind behind Dreamlight 3D. He occasionally posts some neat tricks on his blog. One of the tricks he mentions is that of using a layered 2D photo editing program (e.g., Photoshop or the Gimp) to combine different images that render relatively fast to create something that would otherwise render slow, if you could even set up a scene to achieve it. I’ll demonstrate this trick for you here.
Go back and look at Image #2, which has the mood cube turned on and all the lights on except the ambient light. That render ran in just over 1 minute. Pretty fast. Then take another look at Image #6, which has the mood cube turned off, the candle point lights off, and all other lights, including the ambient light, turned on. That one took five minutes to render. Still not bad. I felt I didn’t need the candle point lights turned on in both images, which is why I went with Image #6 instead of Image #5. Okay. I brought up my 2D photo editing program and loaded those two images in as layers, with Image #6 on the bottom and #2 on top. Then I set Image #2 to have a Screen effect. The resulting image combines the effects of the mood cube and all the lights, including the ambient light, but the total rendering time for the two images used in the combined image is just over six minutes. Combining the two images takes scarcely a minute itself, but there again, you can play with the settings, especially the opacity of the layers.
Image #9, Combination of Images #2 and #6, for Total Rendering Time of Just Over 6 Minutes
To me, Image #9 is the best one of the lot. I’ve got the haze effect in the background that I wanted. The girl figure stands out well. And I still have a gloomy cast to the overall picture.
For the sake of completeness, I’m including one more image. In DAZ Studio, if you don’t load any lights into your scene, your rendered image will be based on the textures you’ve chosen for your scene objects. Adding just one little light anywhere in the scene makes DAZ jump out of this default rendering mode and use your lights as you have them set up. For some images it might be preferable to skip the lighting all together and just use the default rendering scheme. Here’s my scene rendered without any lights, and with the mood cube removed, since it’s related to the use of lights:
Image #10, Mood Cube Off and No Lights in Scene, Rendering Time: 10 Seconds
This doesn’t have as gloomy a feel as I wanted. You can see everything, but too well. There’s no mystery. You use lighting not only to show things, but also to hide things, by directing different amounts of light to different places.
Thanks for reading! Since you’ve read to the end, feel free to save the above images to your computer to better compare them. It can be instructive to put all the images in one folder on your computer and switch back and forth between them in preview mode so that one image replaces the other as you click. I don’t mind. It’s for an educational purpose. Just please respect my rights to the images and don’t distribute them outside the bounds of Fair Use.
So, what do you think of all this? If you’re a digital artist, what are your tricks for getting lighting right? If you’re not a digital artist, does this shed any light for you on the intricacies involved in creating digital art? 😉
OK, you scared me. Seriously, it’s amazing how such small changes in light, literally manipulates our emotions. As Dustin Hoffman would say, Good Form!
Thanks, Grandpa! Light or the absence of it really does affect our emotions, and that’s what the artist is always striving to do. The hard part for me as an artist is to realize how well I’ve done my job in that regard. Feedback always helps tremendously.