Distortion in depth maps???

[Anonymous]

Hi Guys,

I'm working on some computer vision stuff, and I thought making some simple synthetic data in maya would be really convenient especially because I need a normal pass and depth pass. Anyways, Ive rendered out my beauty pass with mental ray and also a depth pass. I then used the camera characteristics to create 3D points at each pixel and then applying the depth to turn it into a point cloud. The results are pretty nifty but i noticed that my ground plane is not flat!

The included image are my results. I know this might be a bit out of scope for a Maya users board but I was wondering if maya/mentalray adds distortion to output images/depth maps by default. (I'm confident I didn't do it!)

I've attached the relevant passes.

[kollig]

May be some gamma issue. Have you checked (or taken into account) that the passes are not linear data anymore but written out with gamma correction?

[mspeer]

Hi!

How is your depth pass rendered, has it a min and max setting?

[kollig]

One further possibility: Mismatch between depth (distance to plane perpendicular to optical axis) and distance (to eye point)?