Essential Blender- P21 pps

Bottom light is the light we're least accustomed to seeing. It has an intense impact when used,
making objects look completely different and often sinister.

Figure 5.3. 06: The bust lit from beneath.

Shadows
Shadow control is half of good lighting.
No shadows
If none of your lamps have shadows turned on, it will look like your objects are floating, as in the
illustration below. To achieve any kind of believability, you need some kind of shadowing.
However, you don't necessarily want every lamp in your scene to cast shadows, for both technical
and artistic reasons.

Figure 5.4. 01: A render with no shadows at all.

Hard vs. Soft Shadows
Turn on Ray Shadows for a standard Blender lamp, and you'll get hard edged shadows. Very
seldom are true, sharp shadows seen in reality. In the physical world, the smaller the light source,
the harder the shadow, and vice versa. Of course, that means that the 100% hard shadows
generated by Ray Shadow don't really exist in the real world, simply because they would require
an infinitely small light source.
There are countless examples of images that have been ruined by hard shadows from several light
sources, crossing each other and confusing the eye. If the artists had paid as much attention to
shadowing as they had to the rest of their scene, this would not have happened.
A guideline to remember: every shadow is soft, even the ones that you remember as hard. We are
not really used to seeing completely sharp shadows, so our eye finds it distracting in rendered
scenes. It is especially noticeable in close-ups, where shadows are always soft to some degree.
To illustrate the difference between hard and soft shadows in real life, look at these two almost
identical photos:

Figure 5.4. 02

The shading defines the object more clearly, but the hard shadow actually becomes part of the
composition of the photograph.

Figure 5.4. 03

The object is less defined, as the light has been spread out by the more diffuse source. There are,
however, no hard shadows to distract the eye, and it makes the photo softer and the subject more
dominant.
In photography, you generally try to avoid hard shadows. In some cases, hard edged shadows can
serve to make the right mood: one of tension or roughness. Hard shadows also bring out a
surface's texturing and bumps, which is why they are not used when attempting to give a sense of
beauty or diffusion to a scene.
As already mentioned, hard shadows can be a tremendous distraction when they litter a scene,
crossing each other in inopportune places. Let's look at an example.

Figure 5.4. 04: Spots with hard edged ray traced shadows.


Figure 5.4. 05: Spots with soft buffer shadows.

Notice the difference between the images above. With soft shadows, the scene becomes much
clearer, as we don't have the hard shadow edges competing with the composition of the rest of the
scene.
There are a couple of ways to create soft shadows in Blender. The first option is the more
physically correct, using time consuming area lamps. They give you a fairly realistic simulation
of shadows as they spread and wash out. This is often preferable for close-ups where details like
these can make a significant difference.
The second option is to use Spot Lamps with soft buffer shadows. You don't get quite the same
crisp and realistic effect as with area lights, but this is not always enough of a drawback to

matter. Combining soft Spots and Area Lamps is often a preferable solution.

Figure 5.4. 06: Hard sunlight.


Figure 5.4. 07: Soft diffuse light.

Lighting Examples
No two images require the same lighting setup, but knowing where to start can sure help. Below
are some of the most common types of lighting situations you'll encounter. These are also
included on the CD for you to explore in detail.
Please don't stick to these examples as though they are law. They are only places to begin, not
out-of-the-box lighting solutions. Remember, no two scenes will work out optimally with the
same light setup.
Outside
Exterior settings require you to stick as closely to reality as possible to be credible to the viewer.
Experimentation with alternative lighting in these settings shouldn't come at the cost of
believability.
Clear day

Figure 6.1 01: Clear day render.

Imagine a clear blue sky with a glaring sun. To obtain lighting like this, you must first understand
what illuminates objects in a real world situation, then try to mimic that in Blender. First, you
have slightly yellowish sunlight. In Blender, this can be done with, you guessed it, the Sun Lamp.
Place it above your scene, pointing downwards at the desired angle (consider whether you want a
morning, midday or afternoon feel).

Figure 6.1. 02: Sunlight alone.

Apart from the sun, you have the blue sky surrounding the scene, illuminating everything with a
soft blue cast and turning every bit of shadow blue. This is called sky illumination.

Figure 6.1. 03: Sky illumination alone.

To properly obtain that effect in Blender, you need to apply some AO to the scene, and add a sky
blue hemi light for the correct color in the shadows. There are alternatives to AO, like setting up
a couple of blue lights around the object, but they struggle to give the nice all-round soft shadows
that AO delivers. The circle light method described earlier can perhaps give a good enough
effect, and is worth a try.

Figure 6.1. 04: Sun light on one side of a tower, with the blue cast from sky illumination on the
other side.

Cloudy day

Figure 6.1. 05: Cloudy day render.

A day with clouds drifting around, blocking the sun every so often. The setup for this is much
like the clear day setup. The only differences are that the sunlight is lower in intensity, depending
on how much cloud cover there is at the time of the render, and the sky illumination color is
toned more toward gray. The energy of the Sun Lamp can be slowly animated to produce the
feeling of the sun moving into areas of greater and lesser cloud coverage.
Overcast day

Figure 6.1. 06: Overcast day render.

We've all experienced one of those days with completely dull, overcast weather. In those cases,
there isn't any direct sun light at all, and the only natural light source left is the gray glow coming
from clouds. Ambient Occlusion with little to no key light source, or circle lighting, will achieve

this effect.

Figure 6.1. 07: On overcast days, shadows are diffuse.

Sunset/Sunrise

Figure 6.1. 08 Sunset/sunrise render.

Staging a scene at sunset or sunrise can add a lot of mood. Set a sun lamp at a very low angle and
give it an orange/red color. Make the sky illumination color (from Hemi Lamps and AO using
Sky Color) a mix between blue and red.
A wide range of colors can actually be applied to a situation like this. From yellows to oranges,
onto reds and sometimes even pinks. Shadow colors from the Hemi Lamps can be dark blues and
purples. It's a very beautiful time of the day that seems to be completely new and different each
time you see it, so there is more than enough variation to play around with.
Clear night

Figure 6.1. 09: Clear night render.

This render represents a night with no clouds, and the moon shining brightly. Moon light can be
cast by a Sun Lamp with a white or slightly blue color. Apart from that, low energy blue/gray sky
illumination is needed as well. When lighting a night scene, though, focus on keeping everything
visible. Instead of turning down lamp energy so low that you cannot see your subjects, tint the
light blue and use detailed rim lighting to show forms.
Overcast night

Figure 6.1. 10: Overcast night render.

Like a clear night, except you remove the moon and make the sky illumination even grayer. This
setup is the hardest to get to work, as it doesn't look very natural if it's bright enough to be able to

see anything clearly. In reality, these lighting conditions (overcast night) mean that there is
almost no discernible light to begin with, so no matter what you do, it won't look natural.
Interiors
In interior settings you encounter a new type of light: artificial. Light bulbs can be divided into
two types: incandescent and fluorescent. Although the difference in the light they cast has
become increasingly small in the last few years due to new technologies, most people can still tell
them apart at a glance.
Incandescent lights

Figure 6.2. 01: A render with incandescent lights hints.

Incandescent light is the kind generated by typical filament bulbs or halogen lamps. Depending
on the bulb, it can have anywhere from a warm yellow/orange to white (typically for newer
types). This form of light is widely used in homes.
In 3D you set up lights where you would place them in real life: on walls and ceilings. A little
AO with an orange cast to it (maybe done with Hemi Lamps), can be used to fake the way that
light bounces around in the room.

Figure 6.2. 02: Light sources in homes are mostly incandescent.

Fluorescent lights

Figure 6.2. 03: A render with fluorescent lights hints.

Fluorescent lights are common in public places, like offices, and sometimes in private
households. Older fluorescent lights have a strong green cast to them (especially on photos where
the photographer used the wrong filter), but newer ones can appear completely white as well.
Some fluorescent lights are even warm in color like incandescent lights, so there's a pretty broad
range of colors to choose from.

Figure 6.2. 04: Fluorescent tubes are often used in industrial and utility settings.

Windows
A window is another light source to keep in mind when working with interior settings. It lights
differently depending on the weather and time of the day.

Figure 6.2. 05: A render of light from windows, on a clear day.

On a clear day, you would have a Sun Lamp shining through the windows, with some blue sky
illumination, very much like the exterior setup explained earlier. In some cases, though, sky
illumination isn't needed and can be excluded from the light setup without much loss of
believability. One can use pretty much the same method described for outside settings to obtain a
cloudy day, overcast day, night, etc.

Figure 6.2. 06: Area lamps outside the windows give a different effect.

For the more overcast weather, or to suggest the windows on the shady side of a house, an
alternative, and more realistic, method is to use Area Lamps. Placing an Area Lamp just outside
each window gives wonderfully diffuse lighting.

Figure 6.2. 07: Sunlight through windows.