Yes, you would need to use JavaScript to set the field visible value on load. Although, JavaScript will not change the default setting of the field. So each time form opens you would need the JavaScript to trigger to make the desired fields visible or not.
I would use an if statement to check if the other field condition is met, if it is then you can use the code below to set the field to visible.
var control = Xrm.Page.ui.controls.get("fieldname")setVisible(true);