Guide: Interpolation at DeoVR & upgrading to 60FPS / 120FPS using the Twixtor plugin

DeoVR aims to deliver the smoothest, most immersive VR experience possible. One major improvement we’ve made is automatic frame interpolation for videos with lower framerates. We'll also explain how to use the Twixtor plugin to convert your footage to 60FPS or even 120FPS. 

What is interpolation in VR?

Interpolation is a technique that generates new in-between frames to create a higher framerate from a lower one. This results in smoother motion, less judder, and an all-around better experience in VR.

Framerate and refresh rate

The best results come from interpolating video by a factor of two. For example, 60FPS footage can be interpolated to 120FPS to match the refresh rate of headsets like the Quest 3S, Quest 3 or Valve Index, or to 90FPS for devices like the Quest 2, Rift, or HTC Vive.

When 60FPS video is viewed on a 120Hz display, each frame is simply shown twice. But interpolating to 120FPS allows every frame to be unique, resulting in noticeably smoother playback.

Avoid simply duplicating frames, as this does nothing to improve visual quality and only increases file size unnecessarily.

Find out more about FPS and framerate at our dedicated blog article. 

Interpolation at DeoVR

At DeoVR, we’re always working to deliver the smoothest, most immersive VR experience possible. One major improvement we’ve made is automatic frame interpolation using ffmpeg for videos with lower framerates. The process estimates motion between existing frames and fills in the gaps, doubling the perceived frame rate. 

DeoVR's automatic interpolation ensures your viewers see it in its smoothest possible form. 30FPS footage will be upgraded to 60FPS (and 25FPS to 50FPS - framerate doubled). 

Important: Never double your FPS framerate without using interpolation techniques. 

When is interpolation required? 

Some cameras, like the ZCam K1 Pro and Vuze XR, capture their highest resolution (5400x2700px) at 30FPS. In these cases, it's recommended to interpolate the footage to 60FPS for smoother playback.

Be sure to double the frame rate rather than setting a fixed 60FPS, since these cameras typically shoot at 29.97FPS. This means the correct target is 59.94FPS for an accurate match.

For the best results, interpolate each camera’s fisheye footage before editing or stitching. While this adds time to the workflow, it can significantly improve quality and reduce distortion.

Upgrading to 60FPS and 120FPS with the Twixtor Plugin

This frame rate interpolation technique uses the Twixtor plugin, which works with various editing software. It algorithmically increases the framerate by generating intermediary frames based on motion between existing ones. Converting 30FPS footage to 60FPS results in smoother motion and a more stable visual experience.

When done correctly, the results are so precise that most viewers can't tell the difference from native 60FPS. However, it's a computationally intensive process—interpolating 60 minutes of 5K video can take several hours.

In VR, 60FPS is considered the minimum standard for comfortable viewing, a point widely agreed upon by the community.

How To Use: 

1. Import a video file. Drag and drop it into the plugin

2. Change the FPS in ‘Sequence > Sequence Settings’ to 59.94 fps

3. Unlink audio/video

4. Go to Speed / Duration and change the speed parameter to 200%

5. Copy Fast Track

6. Combine the two video files in Nest

7. Apply the RE:Vision plug-in Twixtor on the resulting Nest

8. Select the Twixtor settings for interpolation. Make sure the Main speed is set to 50%

9. Export settings. These settings are for interpolating RAW files with the Zcam K1pro 180vr camera. In the case of interpolation of an already finished project, you can set the bitrate value you need. Important! The video must be NOT VR. You DO NOT need to check the ’Video is VR’ box.