This experimental tool introduced in MistikaVR 8.8.7 assists in fixing the vertical parallax issues in Stereo3D workflows. While in theory it could work for many types of rigs, it is only simple to use for VR180 parallel pair rigs.
With this new tool, you can selectively drag vertically areas of one camera: Center, Left, and Right. Then, MistikaVR will modify a combination of camera parameters: Yaw, Pitch, Roll, OffsetX and OffsetY to move affect the selected area, while affecting the other two areas as minimum as reasonably possible.
First, always center the crop circles for both cameras the best you can, as these are the main source of misalignment and are base of good results.
Enter the B&W anaglyph mode to see the vertical misalignments
Preferably Choose a frame where there is no object near the exact center.
To enter or exit the Alignment Mode, toggle the “AM” button in the toolbar, next to the overlay modes.
Notice the mode will only work correctly if the output camera is unmodified. If you aligned the horizon, use “bake in output camera” first.
Select the camera to move by shift+clicking on its center. If both centers are too overlapped, select one of the cameras in the camera list on the left.
Move the camera center into alignment: In B&W anaglyph, the image should become black and white, without any color fringing. Only for the center, you will be able to align in both axis (yaw and pitch).
Follow the horizon line to one side (left or right) and drag the mouse up/down until it aligns vertically. Best, look for horizontal objects, or clearly defined objects where you can easily notice if they are at the same height. Try to align on objects nearest to the horizon line, as for objects up or down of it can be misaligned because of the “interaxial distance” phenomena. Usually some horizontal parallax will remain as colored fringing, as the sides are not necessarily at the same distance as the center.
Do the same for the other side (left or right)
You may recheck and realign the center and both sides again: while the tool tries to move the zones as separately as possible, it is not perfect.