Transformation Tools - Page 7
August 6, 2001
The move, rotation, and scale tools, the topmost three tools in
the right column of the toolbar, are collectively referred to as
transformation tools in any 3D package. They perform
similarly to their 2D counterparts, but, as with everything in
3D, the extra dimension compounds the complexity of the
operations.
If you already tried the move tool, you may have discovered the
key to its operation, or you may have been bewildered by the
apparently inconsistent results of grabbing objects with this
tool. The key to using this tool is taking note of the little
handles Strata gives you to move an object in each direction.
When you select an object with the move tool, little red dots
show up on the plane of each side of the bounding box, as seen
here:
These are the handles by which you can move the object along a
path constrained to a particular axis. For instance, if you want
to move an object only vertically, grab it by the handle
for the z-axis. If you grab an object at any point other than one
of these handles, you can move it in two directions on the
active grid.
The active grid is shown by the blue grid in each viewport. This
is the plane that serves as your conceptual workspace. The y-
plane is active by default, to reflect the real-world conception
of the ground as the base to which matter "sticks," with
structures extending upward from it. To change planes, go to Edit
| Active Grid and choose the plane you want. The hot keys to
change planes are X for the x-plane, Y for the y-plane, and Z for
the z-plane. Once your mind has assimilated to the 3D world (this
takes a while— at least it did for me), you will find it very
helpful to be able to switch between active grids quickly in
order to be able to constrain 2D translations (translation
just means moving something) to the plane you choose.
Tip: You can toggle between the last
transformation tool used and your current other tool (anything
that is not a transformation tool) with theSPACEBAR . This is
especially handy when you are trying to place something with the
move tool and you need to keep adjusting your perspective view to
see if you are getting the desired result.
Scale and rotate work the same way, with the same handles serving
as constraints in their respective directions. The last remaining
trick to master with the transformation tools is the keyboard
modifiers. Don't worry— the concepts behind each modifier are the
same as in 2D graphics tools you already know. The following list
shows the most commonly used options.
- ALT: As you would expect, holding down ALT while you
move or rotate an object creates a copy of the original. ALT
combined with the scale tool causes the object to be modified
from the center instead of the opposite corner.
- SHIFT: This modifier generally constrains the
transformation tools. When you rotate along one axis using SHIFT,
the rotation is constrained to multiples of 45 degrees. SHIFT
used with the scale tool constrains the dimensions of the object
to their original proportions (that is, scales each direction
equally).
- ALT-SHIFT: This modifier works the same as SHIFT with
the scale tool, except that the object scales from its center.
With the move tool, ALT-SHIFT moves the object along the axis
that intersects the origin of the active grid (that is, moves the
object up and down relative to the active grid, or moves the
object closer to or farther away from the active grid).
At this point, you may well be thinking that all these
permutations of the same tools aren't necessary, or that this
kind of stuff is the domain of "advanced features" —
whatever that is. As someone with a fair amount of experience in
3D as a hobby, I can assure you that you will cherish every
option you have to view and transform parts of 3D models and
scenes when they become complex.
Selection - Page 6
Macromedia Flash 5 Developer's Guide
Project—Build a Spaceship - Page 8
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