Alignment Tips
- When adjusting grids in Grid Alignment or Vertex Tweaking modes, if you find that you need to make more than one adjustment (for example, one tap of the translation control), then switch back and forth between adjacent projectors so that the grid lines will eventually “meet in the middle”
- It is recommended that the projectors are on for 15-20 minutes before starting alignment as we have found that the images sometimes move slightly as the projectors warm up
- It is recommended that you save the alignment several times throughout the alignment process so that if you adjust a projector but immediately decide that you need to revert that adjustment, you will be taken back to the most recently saved alignment that you were satisfied with
- If your projectors are significantly out of alignment, don’t just use Vertex Tweaking to try to fix it. Vertex Tweaking is meant only for fine local adjustments. If you just use Vertex Tweaking for gross alignment, you may begin to see significant image tearing and other artifacts on the sphere. Go through each of the 3 alignment steps (Red Ball, Grid, Vertex Tweaking) in order to fix the alignment
- If you are checking your alignment every few weeks, and you find that the alignment is only slightly off, often times this indicates that a projector has been slightly moved (maybe due to a projector being bumped, room vibration from large crowds, etc). Try using the Grid alignment interface and only the Translate controls to adjust it. This may be enough to bring the projector back into alignment. In addition, check to make sure the projector mount screws are tight, and that the mount itself is stable and tight
- After Grid alignment, vertical grid lines should be parallel to each other. If you find that some vertical lines at the top or bottom of the sphere are diverging or crisscrossing in the overlap regions between projectors, this may indicate that the ground to sphere center measurement was not optimally measured (see STEP 3). Re-measure the distance from the ground to the sphere center. If it is indeed accurate, consider adding or subtracting 1 inch from this measurement and then re-entering it into the SOS configuration file as described in STEP 3. Be sure to re-start the main SOS application after making this change. Then, re-run the Grid alignment interface to see if that made a difference
- If you swap out a new projector for an old projector, you may need to change your computer’s “xorg.conf” file so that the computer will know the correct configuration (screen resolution, etc.) for your projector. Please contact sos.support@noaa.gov to ask for technical assistance about how to do this
- The SOS computer automatically backs up alignment files every day. If you
want to reset your alignment files to an older backup, open a terminal and
run the following command (note that you must be logged on to the SOS
computer as the “sos” user to perform this operation):
cp /shared/sos/site-backup.your-computer-name/date/shared/sos/site-config/site-config/alignment/* /shared/sos/site-config/alignment/
where your-computer-name is the name assigned to your computer and date is the timestamp of the alignment files you are interested in restoring (for example: 2012-01-26-00:8:30). Exit the SOS Stream GUI application on the SOS computer and then restart it in order for the new alignment files to take affect