There are 2 options for dot adding in version 3.0, Auto Add Corresponding Dot () and Auto Jump to Corresponding Dot ().
Auto Add Corresponding Dot
If Auto Add Corresponding Dot is on (default), for each click on either image, a corresponding dot will appear automatically on the opposite image.
Generally, the automatically added dot is not located at the correct position, so you have to drag it to the position corresponding to the partner dot's location.
If Auto Add Corresponding Dot is off, you can add key dots on each source image separately. For each click on either image, the program won't automatically generate a corresponding dot on the opposite image.
If there is a single dot on an image, when you move the mouse cursor over the opposite image, the dot will blink to indicate which one should be matched pairs. Just move the cursor to the corresponding position and click, a pair of dots will be done without any drag & drop process. A single dot is presented as "Unpaired Dot" (by default, with red color), but a pair of dots will be presented as "Paired Dot" on the two source images (by default, with green color). Repeat this step to make all the unpaired dots paired.
Auto Jump to Corresponding Dot
If Auto Jump to Corresponding Dot is on, when you added a dot on an image, the mouse cursor will automatically jump to corresponding position on the opposite image. This saves your time to move the mouse cursor to the opposite image, but it looks a little jumpy you may don't like, if so, just make Auto Jump to Corresponding Dot off.
You can combine the two options to get your own favorite dot adding mode. For example, if Auto Add Corresponding Dot is off but Auto Jump to Corresponding Dot is on, you will get the fastest dot adding mode.