In the context of computer animation, interpolation is inbetweening, or filling in frames between the key frames. It typically calculates the in between frames through use of (usually) piecewise polynomial interpolation to draw images semi-automatically. In the context of computer animation, interpolation is inbetweening, or filling in frames between the key frames. It typically calculates the in between frames through use of (usually) piecewise polynomial interpolation to draw images semi-automatically.