from the author:
This article was written with 3ds max 4 in mind. It should be noted that later
versions of 3ds max (version 5) contains a built in global illumination lighting
is one of the most important aspects in creating a realistic render; over saturated,
it looks too fake, undersaturated, too bland. There are several radiosity renderers
on the market today which can also cost an arm and a leg, and take an age to render.
So we have to attempt to fake it somewhat.
illumination is the key to producing a realistic outdoor render (you would modify
this to fit an indoor scene). Global illumination is similar to Ambient lighting;
something of which you should avoid like the plague as it over saturates your
render and makes it look flat. Also, it adds light to places where none may exist.
Faking radiosity can be a bit of a pain to set up, due to calculating light bouncing
and setting up directional light colours so for the meantime, we will stick with
a global illumination setup.
best, and simplest way, to create global illumination is by using a rig setup.
This is a relatively simple method, which kind of emulates Ambient lighting, but
with shadow casting lights, so any corners and dark areas will remain that way.
Imagine a low poly Geosphere, with directional lights attached to every vertex,
with all targets focused at the centre of the Geosphere; thatís the way it should
be created. Use instancing when copying to ensure that any setting you apply to
one, is applied to the others. Every light should have a relatively large falloff
to encompass the target area, overshoot on to illuminate the rest of the scene,
low intensity (as there are a lot of lights) low shadow map size and a high sample
range to feather out the shadow.
rig should also be set up in two separate stages; namely top and bottom halves.
The top half should be the light emanating from the sun and other illuminative
objects, such as the sky, walls (etc), and the bottom half for the ground. You
donít need as many ground lights as you would for the sky, just enough to provide
adequate uplighting. Create these separately though, and instance them as before,
so you can modify the top and bottom lighting individually. Generally, daylight
rendering should consist of two colours, a hot (sun) and a cold (shadow, dark
skies etc). Overall, a very light blue should suffice to break up the scene, but
if you find that it still does not look just right, play around with the lighting
setup; even resorting to making every light unique and feathering off colours
from hot to cold, across the scene.
material amendments can also make a lot of difference; one quick fix method would
be to add a subtle Raytrace or Reflect/Refract map in the reflection slot, with
falloff and a medium to high blur to act as slight illumination from other objects.
Also, play around with anti-aliasing and specular bloom settings to remove any
unwanted harsh edges. Finally, you could also take colours of objects, and place
low intensity lights with the same (or less saturated) colours around them to
illuminate other objects.
rig should consist of more lights at the top than at the bottom, but maintaining
finished render. An additional Ďhotí light has been added to represent the sun,
and a Reflect/Refract map added to reflect the Sky Dome.|
published: 3D World magazine,
Issue 10, March 2001.
Draper, March 2001. Reproduction without permission prohibited.