World of Video/World of Video.iso/gfxprograms/animtools/videotracker/vtutil1.lha/Rot_Doc

Text File | 1993-12-28 | 9KB | 276 lines

 --------- Welcome to ROT! ----------

 To convert the arc filenames back into the proper ones EXECUTE the script
 file called LONGNAMES.  If you ever need to shrink them down again, just
 EXECUTE SHORTNAMES.

 There are more detailed instructions on how to use ROT in the ROThints file,
 but for a quick look at what ROT can do, try the following:

 1) Double-click on ROT to start it up, select 'Load Object' from the
    OBJECT menu, click on 'DemoObject' and then the 'Do it!' button to
    load it. (You may have to use the arrow buttons to scroll through
    the list of files and drawers)

 2) With the ACTION menu, 'Switch to Action Editor'.

 3) Use the ACTION menu again to select 'Load Action'. Click on 'DemoAction'
    and then 'Do it!' to load the action and redraw its 24 frames.

 4) Now hit the 'PLAY' button to enjoy!

 This program is copyrighted by the author, but non-commercial copying is
 encouraged! If you pass it on, please be sure to also copy the files listed
 in the script files 'ShortNames' & 'LongNames', the icon for ROT, and this
 'readme' file.  Have fun!

     ....207


            ROT ver.0.5
 ----------------------------------
 Copyright (c)  04/04/87  C. French
 Non-commercial copying encouraged!
     All other rights reserved
 ----------------------------------

  ROT is a program to generate and
display 3D objects. It is made up of
two sections: the OBJECT editor and
the ACTION editor. The first is used
to create the database of your 3D
object- each point's coords, and the
points used as verticies for each
polygon. The second section defines
an action of 24 steps. At each step
the position or orientation of the
object may be changed. When these
steps or frames are replayed quickly
the object performs your action.
      ---The Object Editor---

  Choose a point to edit with the
slider in the upper-right. Click on
the arrows to move one point at a
time, or anywhere with in the slider
to skip to that point. The current
point is highlighted in the three
views of your object on the left of
the screen. To see how these views
fit together, imagine folding the
Top and Front views away from you
until their edges touch. You end up
with a half-cube that surrounds your
object. When rotated, the object is
moved about the center of this cube.

To change the current point's coords
click in a view. Two of its coords
will be changed so it ends up at the
cursor's location. Which coords are
changed depends on the view in which
you click. For example, the Front
view changes the X and Y coords. By
clicking in at least 2 views you can
position the point where you want it
in all three dimensions. Any point
with all zero coords is considered
nonexistent and is not displayed.

Sometimes two points will appear to
be right on top of one another in a
particular view. Carefully check all
three views to make sure the point
selected is really the one you want
to modify. To zero out a point's
coords, click on the 'ZERO COORDS'
button below the point selection
slider.

There's another slider which is used
to choose the polygon to be edited.
A point can be used as a vertex of
the current polygon by selecting the
proper point with the point slider,
then clicking on 'ADD ABOVE POINT'.
A polygon must have at least three
verticies, but no more than six. The
edges of the currently selected
polygon are highlighted in orange.

The order in which you select the
verticies is important. Go in one
direction around the outside of the
polygon. If you see the orange edges
crossing you'll know the points are
out of order. Hit 'UNDO LAST POINT'
to back up through the vertex list
until the problem disappears.

To get rid of all verticies, you
can click on the 'DELETE POLYGON'
button. Down at the bottom of the
screen is a color palette. The color
which is highlighted is the one that
will be used to fill the currently
selected polygon. To change colors,
just click on the one you want. The
bottom 8 colors are shades of one of
the top eight colors. Cycle through
the available shades by clicking on
'CHANGE SHADES'.

By using the shades for most of your
object's polygons you can produce a
nice 3D effect. This also makes it
easy to change the object's color,
just switch shades. Use the other
colors for details or accents that
you don't want to change.
The three views of your object have
their X, Y, and Z axes labelled. The
arrows by each letter point in the
positive direction along each axis.
Click on an arrow to shift the whole
object in that direction. Three of
the arrows have minus signs next to
them; they'll move the object back.

Using the OBJECT menu you can save
your object's database to disk, load
a previously saved object, or erase
the object entirely. The objects are
saved to disk with '.ROTOBJ' added
onto the names you give them. Don't
type this suffix when loading an
object, just the name itself. Better
yet, just scroll through the list of
objects, click on the one you want,
then click on 'DO IT!'.
       ---The Action Editor---

The 'action' or mini-movie you will
create is 24 frames or steps long.
Select the frame to work on with the
frame slider to the bottom-left of
the screen. The object will be drawn
according to the parameters you set
in the Rotations and Translations
gadgets. To change a value, click on
it and type in what you wish. The
values are checked to make sure they
fall within acceptable limits. The
object is then redrawn according to
your new parameters. By making small
changes from one frame to the next
your object will appear to move. For
example, suppose the Y-rotation is
set to 0 in frame 0, 15 in frame 1,
30 in frame 2, and so on until you
hit frame 23 when it will be 345. If
you now click on the 'PLAY' button
the object will rotate around the Y
axis. You can adjust the speed of
the action with the speed slider on
the right of the screen. By changing
other X, Y, & Z parameters you can
make the object go through all sorts
of weird and wonderful contortions.

To make the action play continuously
look in the ACTION menu and select
'Repeat at end'. A checkmark shows
when this is activated. Now hit PLAY
and the object will spin until you
click on 'STOP'. Another option in
the menu is 'Reverse at end'. With
this activated, the frames will be
shown from first to last and back to
the first again.
The last item in the ACTION menu is
'Calc between...'. With this you can
have the program calculate and draw
a group of frames. When you select
it a requester will pop up asking
for the first and last frame numbers
of the group. Click on the digits to
change them. For each frame between,
the program will calculate the X, Y,
& Z parameters to get from the first
frame to the last. For example, set
the Y-rotation of frame 0 to zero
and frame 12's to 180. Select 'Calc
between...' and set the start & end
frame numbers to 0 and 12. Click on
'DO IT!' and each frame inbetween is
given a larger & larger Y-rotation.
Now set the Y-rotation of frame 23
to 345 and 'Calc between...' frames
12 and 23. You should now have a
smooth rotation about the Y axis.
When calculating steps of rotation,
the direction ROT chooses is the one
that will move the object through
the smallest angle. If the starting
frame is set to zero degrees and the
last frame to 270, the object will
be rotated -90 degrees, not +270.
This is why the example above was
done in two parts. If you tried to
'Calc between...' frames 0 and 23,
ROT would have rotated the object
-15 degrees. (Actually, due to
rounding errors, all frames but the
last would have had a 0 Y-rotation.)

When the frames are played back each
one is drawn on top of the previous
frame, thereby erasing it. But if
you use too large an X-translation
with a large object, the frames will
not overlap very much and a 'trail'
is left on the screen. To fix this
use smaller steps of X-translation
or reduce the size of the object.
(apply a Z-translation to make the
object seem further away.)

When you switch to the Object Editor
and back to the Action Editor, ROT
assumes you must have changed the
object in some way, so the frames it
has are not accurate any more. If
you click on PLAY the program will
first recalculate each frame before
showing the action. This will also
happen if you load an action from
disk. Actions saved to disk have the
suffix '.ROTACT'. Do not type this
when loading it, just the name.
          ---ROT DEMO---

There should be a demo object and
action on this disk. The object is
called 'RobotHead' and the action is
'ShakeHead'. Try loading these to
see what ROT can do. If you pass on
a copy of this program, please be
sure to also copy the demo stuff and
this hint file/program. (ROThints &
ROThints.txt)

---Coming soon to a ROT near you---

Future enhancements:  Saving frames
to disk as DeluxePaint brushes for
use in DVideo etc, specifying the
order of transformations for greater
control over the object, and more!




         ***HAVE FUN!***