8

30 Chapter 17: Rendering
preset formats rather than Custom, the aper ture
width is determined by the format, and this control
is replaced by a text display.
Width and H eight—Letyousettheresolution
of the output image by specif ying the width
and the height of the i mage, in pixels. With
Custom format, you can set these two spinners
independently. With any other format, the two
spinners are locked to the specified aspect ratio,
so adjusting one alters the other. The maximum
w idth and height is 32,768 x 32,768 pixels.
Preset resolution buttons (320x240, 640x480, and so
on)—
Click one of these buttons to choose a preset
resolution. You can customize these buttons:
right-click a button to display the
Configure Preset
dialog (page 3–32)
, which lets you change the
resolution specified by the button.
Image Aspect—Lets you set the aspect ratio of the
image. Changing this value changes the Heig ht
value to m aintain the correct d imensions for the
active resolution. When you use a standard format
rather than Custom, you can’t change the aspect
ratio, and this control is replaced by a text display.
In 3ds Max, the Image Aspect value is always
expressed as a multiplier value. In written
descriptions of film and v ideo, often aspec t
ratio is also described as a ratio. For example,
1.33333 (the default Custom aspect ratio) is often
expressed as 4:3. T his is the standard aspect ratio
for broadcast video (both
NTSC (page 3–1074)
and PAL (page 3–1082) )whenletterboxingis
not used. (Letterboxing shows the f u l l width of a
w ide-screen film format, fr amed by black regions
above and below.)
When using a custom output size, the lock
button to the left of Image Aspect locks the aspect
ratio. When it is on, the Image Aspect spinner
is replaced by a label, and the Width and Height
spinners are locked to each other; adjusting one
alters the other to maintain the aspect-ratio value.
In addition, when the aspe ct ratio is locked,
alteringthePixelAspectvaluealterstheHeight
value to maintain the aspect-ratio value.
Note: Inviewports,thecamera’sconechangesto
reflect the image aspect ratio you set in the Render
Scene dialog. This change takes place when yo u
exit the Render Scene dialog.
Pixel A spect—Sets the aspect ratio of the pixels for
display on another device. The image might look
squashed on your display but wil l display correctly
onthedevicewithdifferentlyshapedpixels.If
you use one of the standard formats rather than
Custom, you can’t change the pixel aspect ratio
and this control is disabled.
The lock button to the left of Pixel Aspect
locks the pixel-aspect ratio. When it is on, the
Pixel Aspect spinner is replaced by a label, and you
can’t change the value. This button is available
only with the Custom format.
Images with different pixel aspects appear stretched or
squashed on a m onitor with square pixels.
Note: For standard NTSC (page 3–1074) ,the
pixel aspect ratio is 0.9. If you are creating 16:9
(0.778) anamorphic images for NTSC, the pixel
aspect ratio should be 1.184. (As in the previous
discussion of Image Aspect, this assumes the
image is not letterboxed.)