Displaced geometry shifting in animations

[wizzackr]

Hi, a strange problem occured in a scene we are trying to render a sequence of:
All displaced geometry shifts slightly in random directions as the camera moves. At first I thought this was due to the massive scene scale (as in units), but scaling the geo down by a factor of a hundred and freezing all transforms did not help at all. Any idea what could be causing this? We are on Maya 2018.6 and Vray Next build 40404
Cheers, J

[Zdravko.Keremidchiev]

Could you share some screenshots or a simple scene that reproduce the issue?

[wizzackr]

Hi Zdravko, thanks for getting back to me.

The reason turned out to be that the position of the geometry in question was too far away from the zero point in maya - most likely, then, a rounding error in that case? Which:
1. is strange, as numbers were not that crazy (20k in x and z, about 2k in y IIRC) and
2. poses a problem when using vray's DOF: As in camera DOF requires me to work in cm (at least in 3.6 that was the case, so correct me if I am wrong) to work correctly, I cannot scale down the scene, which in our case is a large chunk of landscape. So now that we had to scale the scene to meters in order to get the jitter out of the diplacements, we seem to have to fake outworldly camera parameters to make the DOF 'look correct' (f numbers of 80+) as we are basically in macro wonderland for vray. Or am I missing anything here?

In any case: Again, thanks for the fast support - much appreciated to know that you guys are always ready to help!!
J

[Zdravko.Keremidchiev]

Thank you for the update. Did you try disabling View dependent option in the Subdivision and Displacement Quality? Can you send us an example scene that we could investigate?