PNG Background not transparent on nVidia/Windows x64

I’ve installed Avogadro 1.2.0n on two Windows x64 boxes.

On one PC Export → PNG gives a transparent background as expected (PNG has alpha layer).
On the other PC, the same CML file exports a PNG with the same coloured background as the Avogadro view (PNG has no alpha layer).

The transparent PNG is from “Intel® HD Graphics 630” (as provided by the i5-7500 CPU) and the standard Windows Update drivers.

The coloured background is from a nVidia GTX 980 video card and the latest 451.67 drivers.

Is there a setting somewhere in Avogadro or nVidia control panel that might affect this?

The test image in question was just File → Import → Fetch by chemical name → Ammonia.


Unfortunately, the transparent background effect is a question of driver support via OpenGL.

You can ask through Nvidia - but there’s nothing we can do on our end, sorry.