Enable the debug view

To inspect intermediate buffers during frame generation, enter this command in the console of the running Windows non-editor executable:

    

        
        
r.NFRU.ShowDebugView 1

    

The debug view activates a grid that shows you depth, disocclusion, and warped color buffers. If the grid appears and updates during gameplay, it also verifies that the NFRU path is active. The command does not verify NFRU in Development Editor, DebugGame Editor, or Debug Editor because NFRU does not run in those builds.

Image Alt Text:Nine-tile debug view grid showing depth, disocclusion, and warped color buffers for tm1 and tp1Debug view grid for frame generation debugging

Understand the debug grid

The frame generation system displays a 3 × 3 grid of intermediate data. You can use this grid to validate motion estimation, identify disocclusion regions, and verify warping results.

Two time references appear in the grid:

  • tm1 – previous frame
  • tp1 – next frame

Grid layout

The layout of the 3 × 3 grid is as follows:

RowColumn 1Column 2Column 3
1depth tm1depth tp1disocclusion mask tm1
2disocclusion mask tp1motion warped tm1 colormotion warped tp1 color
3optical flow warped tm1 coloroptical flow warped tp1 color

What each tile shows

Depth tiles show the depth buffers for the previous and next frames. Use these tiles to identify geometry and disocclusion regions.

Disocclusion mask tiles highlight pixels that become visible as the camera moves. These areas often require special handling during frame generation.

Motion-warped color tiles display frames reprojected using engine motion vectors. Check these tiles to verify motion-vector accuracy.

Optical flow warped color tiles show frames warped with optical flow estimation. Compare these with the motion-warped tiles to assess optical flow quality.

Use the debug view to troubleshoot

You can use the debug view to identify the following issues during development:

  • Spot incorrect motion vectors
  • Detect disocclusion artifacts
  • Compare motion-vector and optical-flow warping results
  • Diagnose frame interpolation problems

Run stat FrameGen at the same time when you need to correlate a visual issue with generated-frame or frame-pacing statistics.

What you’ve accomplished and what’s next

You’ve now activated the NFRU debug view grid in Unreal Engine and learned how to read it. You can inspect intermediate buffers to validate frame generation and identify common issues.

Next, you’ll use RenderDoc to capture and analyze frame data in greater detail.

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