This is a step by step introduction to using all the features of your InterOscitortm.
Installing the Software and Connecting the Camera and MIDI Synthesizer
See the QuickStart section for instructions on installing the software and connecting a camera and MIDI synthesizer. Once you are getting sounds from your InterOscitortm return to this section to learn how to better play it and control it.
Setting up the Background
The InterOscitortm
works by detecting the difference between you and what is behind you.
Therefore it is important that the area behind you be smooth and even,
with no patterns or edges. Hanging a black cloth on a wall and wearing
white clothes or gloves or standing against a white wall and wearing black
clothes and gloves would be an ideal situation for optimal detection.
However, the InterOscitortm
will still work under less than optimal conditions. The contrast
between your skin color and any solid colored wall or surface behind you
is usually sufficient to obtain good control. Improvements can often
be made by adjusting the camera controls or the video settings in the Options
menu.
Good lighting is also important for the best
control. A single light behind or near the camera, pointed directly
at you is best. A halogen worklight or incandescent worklight with
a reflector both work well for this purpose. A desklamp tilted up
to point at you works well also.
Adjust your background and lighting so that
the screen is blank when you are not standing in front of the camera, and
a clear outline of you shows up when you step in front of the camera.
If there are any other edges in the image (such as of a painting on the
wall behind you) the InterOscitortm
will detect it also and can be fooled into thinking the object is part
of you. (You can use this to play with the InterOscitortm
in reverse by moving the camera instead of your body, and controlling the
sound with the objects that are detected wherever you point the camera.)
The distance between you and the camera will
determine what regions in space control the InterOscitortm.
If you are closer to the camera, the regions will be smaller and closer
together. Further away from the camera the regions will be larger
and farther apart. In this way you can use your whole body to control
the InterOscitortm (from
far away in a large room) or you can control it with the edge of one finger
(from up close on a table top) or anywhere inbetween. Knowing where
these invisible control regions are in the space in front of the camera
will help in gaining precise control over the InterOscitortm.
The picture below may help you visualize how the control regions exist
in space:
The vertical green bars in the diagram above represent the areas where
your hand motion will control the pitch and volume of the sound when the
camera is pointed directly at you.
Orient your computer monitor or laptop display so you can see it as
you stand in front of the camera. This will help you tell what effect
your movements are having.
Setting up for a large distance:
Begin by locating the region that controls
volume; you can do this by standing still in front of the camera, about
6 feet away, and moving your left hand around until you hear a sound changing
volume in response to your hand movements. Then move your hand up
and down until you find the top of the region, where the sound is loudest,
and the bottom of the region, where the sound is softest.
Next, locate the region that controls pitch
by moving your right hand around until you hear a change in pitch in response
to your hand movements. Then move your hand up and down until you
find the top of the region, where the pitch reaches its highest level,
and the bottom of the region, where the pitch reaches its lowest level.
Once you know where the regions are, placing an item such as a small lamp
or other object underneath each hand will help you keep track of where
the regions are. You can also place objects in the air to mark the
high and low points (for example, hang ping pong balls on threads from
the ceiling.)
Setting up for a small distance:
Since the distance between the camera and the
background is shorter, you won't be able to fit your whole body into the
image, but instead can use just your hands, or even one hand to control
the InterOscitortm.
Begin by locating the region that controls
volume, moving your hand around in front of the camera until you hear a
sound changing volume in response to your hand movements. Then move
your hand up and down until you find the top of the region, where the sound
is loudest, and the bottom of the region, where the sound is softest.
Next, locate the region that controls pitch
by moving your other hand around until you hear a change in pitch in response
to your hand movements. Then move your hand up and down until you
find the top of the region, where the pitch reaches its highest level,
and the bottom of the region, where the pitch reaches its lowest level.
Once you know where the regions are, placing a marker such as a piece of
tape or a small object underneath each hand will help you keep track of
where the regions are.
Playing the InterOscitorTM
Now you should be able to play your InterOscitortm by moving your hands up and down. The left hand controls volume and the right hand controls pitch. In general, you play a note by first selecting a pitch with your right hand and then bringing the volume up and then down with the left hand. Much like a violin you will have to get a feel for where the pitch you want is in the space through which you move your hand. However, there are several styles you can use to play your InterOscitortm, some of them easier and some more difficult to master. See the Performance section for suggestions on various playing styles.
Changing the sound
Use the General MIDI menu to change the way your InterOscitortm sounds. The menu items let you choose from a wide variety of instrument sounds that are built into the MIDI synthesizer on your sound card.
Changing the Video
From the Options menu you can call up three
panels that allow you to change the video settings: the Video Format, Video
Source, and Video Display panels. These panels are part of the video
driver that comes with your camera or video digitizer card and hence are
unique to that driver. However, in general their functionality will
be the same for all video devices. See the Reference
page for info on how to change the video settings. Using these panels
you can usually select the horizontal and vertical resolution of the image,
the number of colors in the image, and other items related to the video.
The resolution and number of colors in the image, combined with the efficiency
of the video driver, and the speed of your CPU will have an effect on how
fast the InterOscitortm updates
the screen, and hence how fast it can react to your hand motion.
With smaller images (lower resolution) and fewer colors (less bits per
pixel) the InterOscitortm
will react faster, thus giving you more control over the music. There
is a tradeoff however, since lower resolution also means there are less
positions on the screen that the InterOscitortm
can detect and hence the steps between changes in pitch or volume get bigger.
MIDI has a volume and pitch resolution of 128 steps so a vertical video
resolution of below 128 may possibly result in coarser control (larger
step size) over the sound. Depending on the sound you have selected
this may or may not be noticable. Play with the sounds and video
settings to achieve the best balance between speed and control. A
faster CPU will allow you to use higher resolution images with less impact
on performance. Note that the drivers that come with inexpensive
video cameras often are relatively slow which will limit how fast the InterOscitortm
reacts.
In the Note On/Off mode (settable in the Options/User
Options menu item) the video update rate will determine how often a note
sounds. Thus by changing the video resolution you can change this
"beat" rate. This can be a quite interesting musical effect to play
with. See tip #4 on the Performance Tips
page for information on how the Continuous Controller and Note On/Off modes
work.
Customizing
The Options/User Options menu item brings up a dialog that lets you customize your InterOscitortm in several ways:
Reverse Black and White - When this box is checked it reverses the colors black and white on the screen. This is sometimes useful if you are projecting the video live, or to enhance the visibility of the image so you can better see it from a distance.
Turn on Edge Detection - When this box is checked edge detection is turned on and the images on the computer screen will appear as outlines of whatever the camera is pointed at. If you uncheck this box then the images on the computer screen will appear as solid filled in areas of whatever the camera is pointed at. The InterOscitortm will run faster in this mode on slower computers.
Reverse Left/Right - Checking this box will reverse the image on the screen left/right. This is useful if you are left handed or simply would rather have the controls reversed.
Use Note On/Off instead of Continuous Controller - This box is automatically checked or unchecked when you select a sound from the General MIDI menu, according to what is appropriate for that sound. Some sounds can't be heard at all in the continuous controller mode. All sounds can be heard in the note on/off mode, although they will sound like a piano key being repeatedly pressed rather than a smooth continuous sound like a violin. See the Performance section for the Options/User Options dialog for a detailed explanation of what this control does to the MIDI notes.
Pitch Center - This number sets the center note around which the InterOscitortm will vary the pitch. You can set it anywhere between 1 and 128 (which is the MIDI note number which will be used as the center pitch.) Note all synthesizers respond to the entire range (keyboards for example don't have that many keys). Note 96 is usually middle C.
Pitch Range - Top Note/Bottom Note - These two controls set the highest and lowest pitch that can be reached when you move your hand in front of the camera. Normally they are set to a wide range so that your hand movement will cause the pitch to change over several octaves. By setting the range smaller you can get more precise control over the notes you play (since more hand movement will change the pitch less.) You can also select the range of pitch being played; for example you could set it so that only low notes will be played. The numbers correspond to MIDI note numbers. You can also reverse the Top Note and Bottom Note values which has the effect of reversing which direction you have to move your hand to increase/decrease pitch. Normally pitch increases when you move your hand up; by reversing these settings pitch will increase when you move your hand down.
Volume - Loudest/Softest - These two controls set the loudest and softest volume that be reached when you move your hand in front of the camera. Normally they are set to a wide range so you change the volume from complete silence to very loud. By setting the range smaller you can get more precise control over the volume (since more hand movement will change the volume less.) You can also select the range of volumes available; for example you could set it so that only soft sounds can be played. If the Softest setting is increased then it will not be possible to get complete silence no matter how far you move your hand. You can also reverse the Loudest and Softest values which has the effect of reversing which direction you have to move your hand to increase/decrease volume. Normally volume increases when you move your hand up; by reversing these settings volume will increase when you move your hand down.
See the Performance and the Ideas
sections for more suggestions on how to get the most out of your InterOscitortm.
This entire document is Copyright © 2000, 2001 Peterson
Enterprises