okay, tested for the double-bend-error as flagged by BB. Result: confirmed.

This is how it looks. Red cube, looked at through a bar with all material settings zeroed/blacked out, only the Refract node, IOR 1.5.

Top-right: bar at 0 degrees angle, to locate the cube (cross-hair).
Bottom-right, bar rotated 30 degrees. The cube appears shifted to the right and rotated as we can see the side of it as well.

Theory, scheme at the left.
Red lines: what the camera sees when the bar is transparant only and no refraction takes place.
Light blue lines: due to refraction, the path to the camera gets shifted. First bend to the left into the bar, then bend to the right leaving the bar to the camera.
Dark blue lines: as a result, the camera sees the cube displaced to the right, and that's it. Not rotated or so.

As you can see, the theoretical shift is quite minor compared to what Poser is showing us in the renders.

Green arrows: this is the path light has to follow to make the side of the cube visible to the camera. The light has to bend the same way twice. When it had bend forth and back instead, light from the side would never have reached the camera in any way.

Both effects demonstrate that Poser refraction is bending light the wrong way when it leaves the glass/fluid into the air again. Its bending forth and forth instead of forth and back. It should take the surface normals into account to determine inside and outside. Seems easy to fix to me.

Next issue: can we fix the non-transparency issue as BB suggests? New day tomorrow.

- - - - - 

Usually I'm wrong. But to be effective and efficient, I don't need to be correct or accurate.

visit www.aRtBeeWeb.nl (works) or Missing Manuals (tutorials & reviews) - both need an update though