Single Head Warping Tutorial

This Tutorial provides an example of the use of NTHUSIM to align Single Projector onto a curved screen.

To start, double click on the NTHUSIM icon or run the application from the Windows Start bar. Upon running the application, the main NTHUSIM screen will be shown.

Main NTHUSIM screen

Once an alignment has been performed and saved, NTHUSIM will automatically minimise on start-up. To restore NTHUSIM after being minimized, check in your System Tray next to the time in your bottom Left corner, and click on the NTHUSIM application icon.

Minimising and Restoring

To close the application, simply click on the Close (X) button at the top right hand corner. To hide the application, click the Minimize button at the top right hand corner.

Now we can start the fun part ..... aligning the projected image to the screen! To begin, the main NTHUSIM window will show a number of projector options. Simply select the number of projectors you are using and press "Configure". This will bring up the main configuration screen.

The first thing you will see is a grey screen with a white grid. We refer to as a map - the term will be used further below.

In each corner, a grey control points shown. The control point closest to the mouse cursor will be hightlighted in red indicating which point can be moved. If the map is too far off the screen on initial start-up, you can make the map smaller by pressing the minus key (-) on your keyboard.

To start alignment, simply select the points one at a time and drag them to the corners of your screen. Large movement can be achieved with the mouse and smaller fine movement can be performed with the arrow keys.


Initial map on start-up

Step 1: Moving the control points to the corners

In step 1, each corner control point will be moved to the corner points of the screen.

Once the corners are correct, you will need to adjust for the curvature of the screen. Pressing F2 on your keyboard will add horizontal points. 

F1 - Removes horizontal control points

F2 - Adds horizontal control points

F3 - Removes vertical control points

F4 - Adds vertical control points

Once horizontal control points have been added in step 2, they can be moved and aligned correctly to the screen.

Step 2: Adding horizontal control points

Step 3: Adjusting vertical control points to fit the screen

Depending on your screen and projector setup you may find a number of horizontal and vertical control points will need to be added in order to correctly project onto the curved screen. Additional control points can be added with the F2 (horizontal) and F4 (vertical) keys. These can be moved until a uniform image is achieved (Step 4).

Step 4: Additional points for a more accurate result

Once you are happy with the results, simply press the "s" key to save the configuration.Now you can start your 3d application!

If you are running in demo mode, once you have set up your distortion, close NTHUSIM, and restart to reset your demo time.

Remember: NTHUSIM will need to be started before you run your application. If you close NTHUSIM while your application is running, the distortion will stop.

Running a flight simulation application with NTHUSIM

Running a driving simulation application with NTHUSIM

For those running Double or Triple projector setups, Select the correct option in the main NTHUSIM window and hit Configure. The alignment is identical to the setup previously described for the single projector, just with an additional maps for each projector. When using keyboard shortcuts for zoom, you will be controling the map currently selected, not all maps at once.

With the shared edges of your multiple images, you will need to match up the control points from each map edge together, while using the arrow keys for fine tweaking. This is called Edge Butting. Using various markers on your screen such as tape, or a laser level can greatly assist in getting a really straight edge on your distortion.



Home /\/ Wiki /\/ Top

Customize This