Touch pinch gesture value doesn't reset to zero

Using 4.15.3, I’m trying to implement pinch to zoom. In the same Axis Mapping as my Mouse Wheel Axis, I have added the Pinch gesture. Both Use a scale of 1.

In my player controller blueprint, off the InputAxis event, I take the axis value, multiply it by a speed, and add it to my camera’s spring arm length. I also print it to the screen.

I’m testing this on a Surface Pro 4.

One startup, the value is 0.

scrolling the mouse wheel, it works as expected: the InputAxis value changes from zero, the translation happens, and then the inputAxis returns to zero and everything is still. I’m not sure what kind of values it gets because it returns to zero pretty quickly.

On touching the screen with two fingers, and moving them either together or away from each other, the input axis value changes to around 1.0, and then goes either up or down. When i take my fingers away from the screen, the value does not reset to 0, but stays at 1.11023 or whatever it was last at. Touching the screen again with one finger does not reset the values, unless that touch interacts with the a UMG widget.

I can’t find anything to say if this is or is not the desired effect, but every other input I’ve used resets to zero.

I have just tested this on a different device with Win7 and a large touch screen television, and exported it from 4.16 and 4.17.

The behavior did not change.