Once a calibration is done, you can align it using 3D data and camera position.
In order to perform 3D alignment, you will need:
- The initial calibration (completed) with blending. No VC adjustment and no warping.
- The 3D model and custom content space.
Load the calibration in VIOSO Player and Activate it, so you can see the calibration on the projectors.
Make sure the warping Virtual Canvas (VC) is untouched and it is set by default to full screen.
Open the player view. On the main menu, click the plus icon. Then choose ‘Add Model Item’ then ‘Add MRD’ – give it a name — this will create an MRD file in the playlist.
Double click on it to activate so it is playing.
On the main window, un-check the “Show test image” checkbox. If it is ON, you should be able to see all black on the projection.
Click the calibration menu on the main Core window and choose ‘Show model view control’.
- 3D model- Select your 3D model (custom content space) and click ‘Use’.
- 3D model texture- If there is a texture that you would like to apply to your model after loading it, click ‘Select’ to choose the texture from disk.
Camera based parameters
Choose what camera you are using (fish eye or perspective).
Set the resolution of the camera. Note that it should be the same resolution that was used for the calibration (for fish eye cameras it is recommended to set full resolution). Set Open Angle or Fov angle for the camera (for fish eye camera it is 180-185).
If the camera has a lens that crops some area of the sensor – fill out the field “Border px” with the value of the cropped pixels (most frequently used with fish eye lenses – around 250px).
Camera position parameter
Then the most important factor is to set the camera position. Start with the values that are measured:
- Eye point- Translation parameters (From the view of the camera to the eye point).
- Rotate- Rotation parameters.
The translation and rotation is defined in the system coordinates of the 3D model on screen.
If you have created the 3D model via the Wizard or the VIOSO software, the system is used on the right hand side:
The base points are located:
- Flat plane- Bottom center line.
- Cylinder- At the center of bottom circumference.
- Panadome/Dome- At the center of the sphere.
When the camera has all rotations as zero angles, it is posed as follows:
That means that if camera is mounted on top of the screen pointing down, it is rotated 90 degrees counterclockwise around axis X, meaning rotation x will be -90 or 270.
If it is panadome and the camera is mounted on top of the screen in the center, pointing down means that it located at some height relative to center of the sphere (base point), meaning it has Y translation.
By adding these parameters you will start to see grey texture on the projection screen. This is the real-time rendered image onto the UV texture of the 3D model you have introduced to the system.
To find the best values to position your texture and align it onto your real screen, use all the camera position parameters and border px parameter.
You can type the values in fields from the keyboard. You can use the scroll-wheel or you can use the keyboard arrows.
If you hold SHIFT and change the value in the field, it will change with bigger step (coarse). If you hold CTRL and change the value in the field it will change with smaller step (fine).
Align the testing grid as best you can by carefully tweaking all of the values mentioned above. It is natural that this procedure takes a while.
It is recommended to position the grey test picture in a way that it overshoots the screen a little bit, so that you can get rid of the ugly edge of the texture and then mask it out.
If you did your best and the alignment is still not perfect, you can use the warping tools, which is right next to it.
Note that warping will be still in camera perspective, as the calibration is not converted yet. Refer to the VIOSO Core Warping section to know more about the warping tools.
When you are done, select the camera at the bottom, and save its position (pose).
Now you have performed MRD alignment of your calibration (MRD adjustment).