I‘m struggling to render accurate depth maps of different 3D models using Cycles and was wondering if anybody has/had similar problems and how she/he resolved them. I would greatly apprichiate help! :)
I attempted two different methods to obtain depth maps:
1) Via a camera node, exporting raw Z depth.
2) By rendering the Z pass and later convert them to paralell depths as in 1). In both cases, I store the depth as OpenEXR files. It is my understanding that this is the go-to format in such cases as it is designed to store linear data and, thus, should not distort my Z depth information.
However, in both cases I run into the same problem: I still have inaccurate depth values. I experimented with a simple scene - just a flat plane that is fronto-paralell to the camera. On top of this plane I put a ramp. When rendering this simple scene, e.g. in case of 1), these inacuraccies manifest as staircase artefacts on the ramp.
The thing is, I need accurate Z depths to test my algorithms on this data. So I can't turn on anti-aliasing, since that would also smooth the depth boundaries between fore- and background objects.
EDIT: blend-exchange.giantcowfilms.com/b/6241 & imgur.com/a/mj3JeTR