  Real-time rendering has been embracing ever-demanding effects, such as ray
tracing. However, rendering such effects in high resolution and high frame rate
remains challenging. Frame extrapolation methods, which don't introduce
additional latency as opposed to frame interpolation methods such as DLSS 3 and
FSR 3, boost the frame rate by generating future frames based on previous
frames. However, it is a more challenging task because of the lack of
information in the disocclusion regions, and recent methods also have a high
engine integration cost due to requiring G-buffers as input. We propose a
\emph{G-buffer free} frame extrapolation, GFFE, with a novel heuristic
framework and an efficient neural network, to plausibly generate new frames in
real-time without introducing additional latency. We analyze the motion of
dynamic fragments and different types of disocclusions, and design the
corresponding modules of the extrapolation block to handle them. After filling
disocclusions, a light-weight shading correction network is used to correct
shading and improve overall quality. GFFE achieves comparable or better results
compared to previous interpolation as well as G-buffer-dependent extrapolation
methods, with more efficient performance and easier game integration.
