'\"macro stdmacro
.TH revo 1
.SH NAME
revo \- creates revolved 3d surfaces
.SH SYNOPSIS
.B revo
.SH DESCRIPTION
.I revo
is an interactive Inventor program for creating 3d objects by drawing 
a curve and then revolving it around an axis.
.PP
The program has two main viewing windows: the curve view and the
3d rendered view.  To create a object, click the left mouse button
in the curve view near the default blue line.
Hold the button down and continue to move the mouse, 
the point will be dragged.  You can drag existing
points on the curve by clicking and dragging.  To delete a point
from the curve, simply click the point to select it, and then
press the BACKSPACE key to remove it.
.PP
As you draw the curve in the curve view, the 3d object is automatically
draw in 3d in the other view.  The 3d rendered view allows you 
to view your masterpiece by clicking and dragging in the view.
Experiment with the various mouse buttons to gain control over the viewing.
Press the right mouse button in the 3d rendered view, and
select the `Functions/Help' entry for more help on 3d viewing.
.PP
.I Revo
allows you to sketch out a line which is then rotated around an 
axis to form a surface of revolution.  
The left-hand window allows you to edit the line, 
and the right-hand window lets you view the resulting surface.
.PP
Initially, a very simple surface of revolution is shown; 
a single line segment is rotated about the vertical axis to form a cylinder.
To add points onto the end (bottom) of this cylinder, 
just click the left mouse button where you want the new point to appear.
To move an existing point, just position the mouse near the point 
(a small cross will appear), then press the left mouse button 
and drag the point to its new position.  When you are satisfied with 
its location, release the left mouse button. You can also insert 
points in the middle of a line segment by placing the mouse near the segment, 
pressing the left mouse and dragging the new point to the desired location.
.PP
The 
.I Clear
button below the main windows is an easy way of deleting 
all the points.  You can also use the Backspace or Delete keys on the 
keyboard to delete points. The 
.I Copy
button will copy the shape you have 
created to the Xt clipboard.  You can then paste the shape into an 
Open Inventor application that supports paste, like the SceneViewer 
(revo does not support paste). You can change the number of sides 
used in the surface of revolution by typing into the 
.I #sides
Motif text widget.
.PP
Normals are calculated automatically whenever the line changes.  
If the angle between two segments is small enough, a "smooth" normal 
will be generated.  If the angle is too great, a "crease" will be 
automatically generated.  Putting two consecutive profile points at 
the same location is another way of generating sharp creases.
To save your objects you must first copy them to an application 
(such as the SceneViewer) that supports save.  
The 3d view is a standard Open Inventor Examiner Viewer.  
Press the right mouse button for a menu that will allow you to 
turn on the Examiner Viewer decorations, change drawing styles, and get help.
This program is a lot like the 
.I revolve
demo program, which was 
written using only the Iris GL.  This program is approximately half the 
number of lines of code as the GL version, and has more features 
(e.g. changing the number of sides of the surface, copy to the Xt 
clipboard, the different drawstyles supported by the Examiner Viewer).  
No GL calls are made in the source code to this program, 
only Inventor calls (which uses Open GL).
.TP
.I Number of sides
This number sets the number of sides the object will have around
the revolution.  
.TP
.I Copy
Will copy your object onto the X clipboard, where it can be pasted
into another Inventor program (e.g., showcase, SceneViewer).
.TP
.I Clear
Removes your masterpiece and starts over again.
.TP
.I About
Displays a short description about revo.
.TP
.I Quit
Exits revo.  Note that the data copied to the X clipboard with
the copy button will disappear when revo exits, so be sure to
paste your creations before exiting.
.SH SOURCE CODE
Note that the source code to 
.I revo 
comes with the
.I Open Inventor 3d Toolkit.
.SH FILES
/usr/share/src/Inventor/demos/revo/* - Source to revo
.SH SEE ALSO
SceneViewer, drop, gview, inventor, ivview, maze,
noodle, qmorf, showcase, textomatic