As mentioned before, you can always use another interpolation type by selecting it manually from the parameter’s interpolation field. On the other hand, when working with a Shader where you want most of your parameter adjustments to affect the image globally, you might set the Default Interpolation menu to Constant. For example, when you create an animated transition between two shapes, you might want to set the Default Interpolation menu to Ease In/Out to create natural movement between keyframes. Since interpolation determines how Title Studio creates intermediate values between two keyframes, you can use this option to set the initial interpolation type.
Manual changes to interpolation type are still available for the individual parameters. The Default Interpolation menu sets the default interpolation type assigned when you adjust any parameter at a keyframe. Part of the Options Palette, the Keyframe Palette is used to set the default behavior of keyframes in a project.