Essential Blender- P21 pps

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.. With s

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

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

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

Figure 6.2 08: Sunlight through windows with blinds Notice the beautiful reflected light

Special Cases

From time to time you encounter situations that just don't fit in with the standards you're used to observing

Space

Figure 6.3 01: A render of a planet

In space, things are a bit simpler than here on Earth There is no big blue sky casting illumination from all directions A single sun lamp, in most cases, is all you need Illumination from the surrounding universe of stars is there, but it's negligible and not worth setting up in most cases Notice how most entertainment productions that include space scenes use nebulae and other large scale structures to give color and light to scenes that would lack it in reality

Studio lighting

The key word when it comes to studio lighting is control The lights can be set up to exactly suit the photographer's needs Studio lighting is an enormous subject that could have a chapter, a book, or an entire book series of its own If you're really interested in replicating studio lighting

in 3D, there are many books and resources already available What follows is just one of many ways to achieve a studio lighting effect

The studio setups most commonly encountered by the average person are product shots Big, soft lights, often with diffuser panels, are used to light subjects evenly while eliminating distracting shadows In 3D, this means that you must use Area Lamps or Spot Lamps with soft buffered

shadows This type of setup usually has lights arrayed around a subject for uniform illumination

at a high level of intensity, "burning" any details completely out of the background

Figure 6.3 02: A render simulating studio lighting for a product shot

Figure 6.3 03: The shot set up in Blender

Camera flash

Figure 6.3 04: Camera flash render

We all know the kind of amateur photos where the light from the camera's flash is way too

prominent, almost destroying the image However, if you want to make a 3D image appear like it was indeed snapped with an amateur camera, adding a bright lamp just above the camera can easily give an extra level of realism Nothing is perfect in reality, neither cameras nor

cameramen Sometimes duplicating bad real-world practices in 3D can enhance believability

Conclusion

Hopefully this chapter has given you a good start on the way to lighting your scenes effectively Don't forget that without proper lighting your weeks of hard work on that model and materials will be so much less than it could

Let there be light!