154
O
N THE PREVIOUS PAGE WE
looked at setting the vanishing point.
When you’re looking at the inside of things
– boxes, rooms, streets – there’s just a single
vanishing point: this is one point perspective.
When you’re looking at the outside corners
of objects you need to use not one, but two
vanishing points, at the far left (VPL) and far
right (VPR) of the field of view. All planes in
the image will tend to one or other of these
vanishing points.
Deciding where to place the VPL and
VPR is a tricky matter, since it affects the
perspective of the image in the same way as
when you switch between a wide angle and a
telephoto lens.
Fortunately, technology has come to our
rescue. The screen shot above is from a java
applet written by the talented programmer
Cathi Sanders, which she has kindly agreed to
let me include with this book. It shows how the
perspective process works: you can move either
the VPL or the VPR along the horizon line,
and change the dimensions and position of the
yellow box by dragging any of the red dots, to
see exactly how altering the vanishing points
affects the perspective of the scene. You’ll find
this java applet on the website, and it can be
opened in any standard browser.
COW IMAGE: HEMERA PHOTO-OBJECTS
1
Here’s our task: we’ve got a field with a clear, visible
horizon in it, and a cow gazing out at us. Fortunately, the
cow’s on a separate layer so we can hide it easily. Our job is to
put the cow in a glass tank, Damien Hirst style: and there’s a
panel of framed glass there waiting for us.
6
Move the original panel well out of the way, then take a
copy of it (hold O A and drag with the Move tool)
and enter Free Transform mode. Now hold C L as you
move each corner handle to distort the panel to fit the guide
lines: hold S as you drag to keep the verticals straight!
3
Now draw two more verticals, again with the Shapes
tool, at the left and right corners of the tank. So far, we’ve
drawn in the two sides facing us: but because this is a glass
tank, we’ll need to draw in the back panels as well, which we’ll
do next.
Two point perspective
6
Getting into perspective
SHORTCUTS
MAC WIN BOTH
155
HOT TIP
You’ll get the most
successful results
when you balance
the left and right
vanishing points
so that they’re at
equal distances
each side of the
center of your
artwork. The closer
together they are,
the more extreme
the perspective of
the scene will be,
just as if you were
using a wide angle
lens.
Oh, and for
those of you
who don’t know:
Damien Hirst is
a contemporary
British artist
renowned for
cutting animals in
half and pickling
them in clear tanks
of formaldehyde.
2
The trouble is, the image isn’t nearly wide enough to
draw our vanishing point lines. There’s a simple solution:
we’ll draw them using pen paths. First, zoom out until your
image has plenty of spare window space around it (hide the
panel and cow layers, so you can see what’s going on). Now,
using the Line tool set to Path mode, draw in
the horizon line on the visible horizon. Draw
a vertical for the nearest corner, then add perspective lines to
arbitrary left and right vanishing points. The position of these
points is largely up to you.
7
Repeat this procedure with three more copies of the
original panel to make the other front side and the two
back sides. Remember to move the back side layers behind the
cow! As long as you make the panels fit the guide lines, the
perspective should work perfectly.
8
As a final step, I’ve darkened the right-hand panel and
added a lid and base to the tank. The shadow is easily
made by desaturating a further copy of the panel (using
CSu LSu), setting its layer mode to Multiply,
and then distorting it so it lies along the ground.
4
Starting at the four back corners, draw lines from each
to the opposite vanishing points. All the lines drawn will
now be perfectly in perspective: just for good measure, we can
add a final vertical in the far corner to aid us in positioning the
back panels.
5
We now want to distort those panels to fit the space. But
you can’t use Free Transform when a path is visible, or the
path will be distorted instead; so make a new layer, turn the
path into a selection, and fill the perspective lines with a color.
Time to show that cow and panel again!
How to Cheat in Photoshop CC
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