Different Ways to Light a Bedroom

Ending this series on lighting is interior lighting. Compared to a character and an exterior set, I found interior set the most difficult to light. Here is why.

Interiors are enclosed space usually lit naturally by sunlight. This means the only light sources are openings such as the windows on the images above. The big question is how do we bounce light from the windows to all other parts of the room? (This bounce light question can be answered easily in the two other cases. For characters, we simply add more fill lights. For exterior set, the need for bounce light is minimized by lighting from the sky.) There are two answers that I know of.

The first is using Final Gather to bounce the light. This is, after all, what Final Gather was designed to achieve. The first image was rendered using this method.
The main disadvantage of this method is render time. The Final Gathering step took 2+ hours (I needed 3 diffuse bounces to reach the floor area under the bed); the rendering time took 5 hours. The reason for 5-hour render time is noise elimination. This method uses no fill light at all, requiring high sampling quality to eliminate shadow noise.
Another disadvantage is artistic control. Controlling image contrast with lighting alone is impossible; post-render color correction is needed.

The other alternative is using an ambient light. You can read about this method as explained by Zap Anderson on his blog. The ambient light is an omni light with Ambient Occlusion projection map.
This method renders much faster. The ambient light helps to (1) eliminate the need for Final Gather diffuse bounce (I used Final Gather with 0 diffuse bounce) as well as (2) minimize the visibility of shadow noise from the key lights (the window lights).
Finally, this method allows more artistic control. By setting different intensity for key light and ambient light, I could control image contrast even at rendering stage.

Different Ways to Light a Town Center

After character lighting, I continued with exterior set lighting. Getting a basic lighting for a set is not difficult. The difficulties mainly come from working with a large file and fixing mistakes in the model; not from lighting itself.

Creating a good-looking mood lighting, though, takes more effort. The first difficulty is designing interesting lighting schemes. I researched for ideas at Pinterest. There are many boards there to get lighting schemes from, such as 2D3D_env board and Digital Environments board.

Next step is implementing the lighting schemes I picked, which are 2D paintings, in a 3D scene. Using 3ds Max Daylight System with mental ray Sun & mental ray Sky helps a lot. I spent most of my time placing the Sun. After that, I only needed to make minor adjustments. One interesting step is perhaps about getting cloud shadow. I experimented placing a floating box near the Sun and was pleasantly surprised that mental ray Sun creates a soft shadow as expected. I used this trick for the "Morning" image. If you know another trick, please share it in the comments.

I did color corrections in Photoshop. Color Balance adjustment layers are effective to get colors close to those in the lighting schemes. I also cheated lighting quite a bit. For example, in the "Morning" image, I used an extra rim lighting on the foreground tree to get more details. In the "Sunrise" image, I brightened the bright line along the road, which made the lit wall on the left extremely bright. I hand-painted a layer mask so that only the road was brightened.

As always, feel free to tell me what you think in the comments.

Different Ways to Light a Character

Different ways to light Bruce Willis

Recently I have been practicing lighting, specifically character lighting. First big question: How many ways should I light the character?

After a little research, I decided to cover 7 ways that I thought were large enough a variety. In addition, 7 cases should be enough opportunity to develop an understanding of what is important in lighting.

The more I researched for reference, though, the more interesting lighting schemes I came across. This gave me the one extra case to make a total of 8 schemes above.

Next big questions:

• Should I vary the camera angle to maximize impact?
• Should I employ compositing, again, to maximize impact?

Well, I am hoping to use these as material for a short course on lighting. The course goal is to give students chance to experience lighting as much as possible. This means the class is simply lighting, lighting, and lighting.

With this in mind, I decided to keep one camera angle so that comparisons between lighting schemes will be more objective. I also decided to forego compositing to keep the focus on lighting.

This does not mean that I am not planning to polish these :)

3ds Max 2014 Visual Diagnostics Work Around

Currently I am trying out 3ds Max 2014. I have been using 3ds Max 2011 since 2010, so I thought it was time for me to make the switch. As expected, there are changes to get used to.

One such change is the Mental Ray visual diagnostics. (You can find this in Render Setup dialog > Processing tab.) I use it often to make sure that I have enough Final Gather points. To my surprise, the "Enable" check box is greyed out, unclickable.

Figure 1. "Enable" checkbox is unclickable

A quick search revealed that this is because the new default Sampling Mode "Unified/Raytraced" does not work with the diagnostics feature. (You can find this in Render Setup dialog > Renderer tab.) The work-around is by setting the Sampling Mode to "Classic/Raytraced". The visual diagnostics will work as previously.

Figure 2. Changing the Sampling Mode from "Unified/Raytraced" to "Classic/Raytraced"

Here is an article at Autodesk's AREA blog that explains this work-around: http://area.autodesk.com/blogs/maxstation/b001-mental-ray-diagnosis.

Edited on 5 March 2015.