Hi Twinmotion Support Team,
I would like to report a severe bug/pipeline stall that occurs when exporting video sequences in Twinmotion.
Issue Description: Whenever I render a video in Lumen mode containing an animated video material (an MP4 file applied to an emissive surface such as a TV screen or an LED billboard), the GPU completely stops processing.
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The GPU utilization drops to nearly 0% - 1% (monitored via Task Manager).
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The export process stalls dramatically: a simple 10-second sequence takes several hours to render.
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This issue appears to persist across different versions of the software.
Expected Behavior: The GPU should maintain normal utilization to accelerate the Lumen rendering pipeline, and the video export should complete within a reasonable timeframe.
Steps to Reproduce:
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Open a scene with Lumen enabled (Global Illumination & Reflections).
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Assign an MP4 video file as an emissive/diffuse texture to a screen or display mesh.
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Set up a short video sequence (e.g., 10 seconds) and start the export.
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Check GPU load in Task Manager — the GPU remains completely idle while render time skyrockets.
Please investigate this issue, as it creates a critical bottleneck when working with animated media screens.
Thank you,
