NvAPI_GPU_SetScanoutWarping() affecting scene brightness

Hello all,

We’re using NvAPI_GPU_SetScanoutWarping() to correct for projecting onto a curved surface. We’ve been using the same software to make this API call for years, but on a recent project we found that this call is severely darkening the scene. It is roughly equivalent in appearance to halving the brightness.

We’ve verified that we’re not also calling NvAPI_GPU_SetScanoutIntensity(). This doesn’t require running a particular image generator to see the effect - even Windows desktop background is enough to show this effect.

We’re using a P6000, tested with driver versions 391.58 and 391.89 (latest), and nvAPI v1.10 (R343).

I’ll try updating to the latest API version, but in the meantime has anyone else experienced something similar? Is this a known issue?

Thanks,

Kerry

Updating to the latest API version (R396) did not help. This issue is repeatable when we connect a monitor instead of the projector that we usually use (and is easier to photograph - see images here: https://postimg.cc/gallery/2womspsa6/).

I tried this on a different machine using a K6000 card and an older driver, and was unable to reproduce the effect.

Any input is welcome.

Thanks,

Kerry

We managed to resolve the issue (at least temporarily) by uninstalling the driver and re-installing, being sure to choose “Custom” and “Clean install” options. Simply uninstalling/re-installing with “Express” did not correct the issue.

We have not determined what caused the issue originally, however.

Thanks,

Kerry