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To create natural-looking
reflections, we must understand what to look for. The best way
to learn about natural reflections is to look at some.
For openers, we need an object and a reflecting
surface. We can start with a white jug on a table. Compare these
two images of the same jug on the same table.
Notice how a change in the camera angle produces
a substantially different reflection. On the right, the jug's
handle is visible, while it doesn't show in the image on the
left. (In addition to the relationship among the object, the
surface and the camera, the lighting is slightly different.)
Also take a look at the table just below the
jug. With the lower camera angle (right), more of the underside
of the jug is showing, areas that have to be created manually to
produce a realistic reflection.
A third view of the jug and table illustrates
another feature of reflections in nature. Take a close look at
the lowest area of reflection on the table, the jug's spout.
You'll see the irregularities of the table surface, emphasized
by the low light source.
Because the light was close to the table top,
the slight irregularities in the table's surface become much
more noticeable. The light creates shadows and highlights that
would not be seen if the light was directly above the table.
The texture of the tabletop is also visible in
this next image, a reflection of a book.
Other than the texture, this reflection is
reasonably simple to replicate. One flat surface is being
reflected onto another flat surface. Compare that to the
reflection of the round jug. First, take a look at the shape of
the reflection.
Next, take a look at the line of reflection, the
axis across which the subject is reflected. While there's a nice
straight line to reflect the rectangular book, the jug's curved
base provides a larger challenge.
The curved base of the jug represents a
challenge. Rather than a nice straight line of reflection (red),
the lower edge where it is in contact with the reflecting
surface (the table), requires a curve. (You can think of it as a
series of short straight lines of reflection.)
Likewise, when you can see two sides of a
rectangular object, both in or near contact with the reflecting
surface, you have multiple lines of reflection.
The corners are points that deserve attention
when reflecting. In this example, the points where the subject
is in contact with the reflecting surface are highlighted in
red. Corners that are away from the surface are in yellow.
In addition, notice in the following figure that
even in this simple reflection there's an area that's undefined
in the original object. That part of the book's underside
(indicated by the white dashed line) would have to be created to
simulate a reflection. The area of concern is caused by corners
and edges that are not in direct contact with the reflecting
surface.
It's also important that a reflection follow the
contours of the original object. Areas visible behind the
original are not reflected, nor are surfaces away from the
reflecting surface. The outline shows the part of the subject
that should be reflected.
In addition to the upper surface of the top
book, there's a bit of the lowest book that must be excluded
from a reflection as well.
Another tricky consideration is reflections onto
the subject. For example, the clasps on the toolbox in this
image would reflect the surface upon which the toolbox is
sitting. Those reflections (or a reasonable approximation) would
have to be added to the clasps before the box as a whole is
reflected.
Also keep in mind such things as candle flames
and light bulbs. If visible in a reflection, they may need
special attention to look like realistic light sources. |