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PRO Feature - Video export requires a PRO subscription. Upgrade to PRO for access.

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Video Export

Export your trajectory animations as high-quality MP4 videos for presentations, publications, or supplementary materials.

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Getting Started

  1. Load a supported in-memory multi-frame GRO or native GROMACS session.
  2. Open the RENDER tab.
  3. In Export Center, choose Standard movie or Path-traced movie.
  4. Configure the frame range, step, FPS, quality, resolution, and loop count.
  5. Start the export and keep the app tab open until encoding finishes.

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Export Settings

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Quality Levels

CRF (Constant Rate Factor) controls H.264 compression. Lower values = higher quality but larger files.

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Export Process

The export runs in two phases:

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Phase 1: Frame Rendering

Each frame is rendered and captured as a PNG image. A progress bar shows the current frame and estimated time remaining.

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Phase 2: Video Encoding

All frames are encoded into an MP4 video using H.264 codec via FFmpeg (running in the browser via WebAssembly). A second progress bar tracks the encoding progress.

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Path Tracer Mode

When using Path Tracer render mode, each frame is rendered with the specified number of path tracing samples. This produces photorealistic output but is significantly slower. The CPU still-image fallback is still-image only. It does not apply to MP4 generation, so path-traced video remains GPU/WebGL path-tracer mode. When TRACE cages or H-bonds are active, WebGL and path-traced video export prepare the overlay for each frame through the same frame-aware path before capture. If a frame cannot refresh its analysis overlay, Clavis reports the frame-stage failure instead of silently exporting stale frame-0 cages across the whole video. HTR ring and occupied-guest overlays cannot currently be refreshed safely for each movie frame. Hide those overlays before export when Clavis reports that requirement. Native binary GROMACS sessions (.gro + .xtc/.trr and .tpr + .xtc/.trr) expose MP4 movie export controls when the indexed trajectory has multiple frames. During export, Clavis loads each selected native frame slice before preparing TRACE cage and H-bond overlays so videos do not reuse stale frame-0 analysis geometry. Large streamed GRO and mapped LAMMPS sessions support browser-local playback and analysis, but the current Export Center marks movie export unavailable for those streamed trajectory formats.
Path-traced video export can take several minutes to hours depending on frame count and sample settings. Use standard WebGL mode for quick previews.

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Output

The exported MP4 file is automatically downloaded with a descriptive filename:
The naming format is: clavis_frames_{start}-{end}_{fps}fps_{quality}.mp4 After success, cancellation, or failure, Clavis returns to the frame that was active before export and restores the previous cage, ring, H-bond, and occupied-guest visibility state.

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Tips

  • Preview first: Use Low quality with a small frame range to check the result before a full export
  • Even dimensions: The exporter automatically ensures even width and height (required for H.264)
  • Cancel anytime: Click Cancel during either phase to abort the export
  • Loop for GIF-like effect: Set loop count > 1 to create seamless repeating animations