The goal behind this problem is to output motion vector data into a separate image sequence.
So far having it as part of multi-layer EXR seems to be the only way it works properly, but I’d like it separated into it’s own image sequence and ideally normalized to 0-1 color range.
Here’s what I’ve tried:
- Rendering into simple EXR never includes an alpha channel (the forth “w” channel), even with “RGBA” mode turned on. Is this a bug?
- Rendering into a RGBA TIF or PNG by splitting vector into channels, remapping them, and combining the results in corrupted values, R and B channels get stuck to 1 for some reason.
- As debug, omitting A channel from the above setup results into more expected behavior, although it does not mach up with EXR values which acts as ground truth.
(to test I remap float values of EXR with the same -75/75 range in After effects)
(“75” is arbitrarily chosen as a practical “limit” of motion vectors based on my current scene.)
Here’s a view of the nodes. The “remap 4D” is just a stack of 4 remap nodes because compositor lacks nodes that operate on 4D vectors:
I’m overriding color management in file output nodes to what I understand to be neutral/none alteration suitable for non color data like this
Would anybody have any insights into inconsistencies I experience, or whether or not alpha-less EXR is a bug, and how could I achieve my end goal?