Add a simple example to display Open Photogrammetry Format datasets

[abey79]

What

Add a simple example to display Open Photogrammetry Format datasets

This example is currently minimalist in that there is lots more in the OPF that could be displayed, such as uncalibrated vs. calibrated cameras, matches between points and cameras, etc. Also, I opted to display each calibrated camera as individual frames in the timeline, as displaying them currently spams the viewer with image views.

Closes #2246

Would greatly benefit from #1136
Blocked by #2244

Checklist

• I have read and agree to Contributor Guide and the Code of Conduct
• I've included a screenshot or gif (if applicable)

PR Build Summary: https://build.rerun.io/pr/2512

Docs preview: https://rerun.io/preview/c1fd3e3/docs
Examples preview: https://rerun.io/preview/c1fd3e3/examples

[abey79]

Here are the issues I encountered while working on this:

• As noted, all the image space views are annoying when trying to display many cameras on a single frame.
• Getting the camera orientation right was a struggle. I ended up adding a correction term in the transform's matrix. I expected rr.log_view_coordinates to work but couldn't get them to work.
• I experienced inconsistencies in how the 3D camera frustum widget display is scaled. Running this example with olympic in a new viewer yields this:
  
  Then, running rainwater and immediately after olympic again, in the same viewer, yields this:
  
• Maybe related: double-clicking on the camera frustum yields the wrong orientation.

[emilk]

Having an option to show all the camera poses at once would be great, because that is something I want to demo a lot, but have no demo for

[emilk]

Requires Python 3.10:

❯ pip install -r examples/python/open_photogrammetry_format/requirements.txt
Requirement already satisfied: numpy in ./venv/lib/python3.8/site-packages (from -r examples/python/open_photogrammetry_format/requirements.txt (line 1)) (1.23.0)
ERROR: Ignored the following versions that require a different python version: 1.0.0 Requires-Python >=3.10; 1.1.0 Requires-Python >=3.10
ERROR: Could not find a version that satisfies the requirement pyopf (from versions: none)
ERROR: No matching distribution found for pyopf

[abey79]

Having an option to show all the camera poses at once would be great, because that is something I want to demo a lot, but have no demo for

I can add an option 👍🏻

[abey79]

Requires Python 3.10:

Oh indeed, pyopf wants Python 3.10. No way around using that lib for this example. Just a mention in the README?

Also, how was this not caught by the CI?

[emilk]

Requires Python 3.10:

Just a mention in the README?

Yes!

Also, how was this not caught by the CI?

I don't think we run pip install -r examples/python/requirements.txt on CI.

Related:

• Make sure all developers are on Python 3.8 #2254

[emilk]

Really nice to have a multi-view example and an example with a bigger point cloud (1.5 M)

[abey79]

Really nice to have a multi-view example and an example with a bigger point cloud (1.5 M)

--dataset rivaz gets you 35M ;)

[abey79]

Having an option to show all the camera poses at once would be great, because that is something I want to demo a lot, but have no demo for

Just added support for that:

python examples/python/open_photogrammetry_format/main.py --no-frames

The UX is abysmal though.

[emilk]

How do I easily try this?

I can run python3.10 examples/python/open_photogrammetry_format/main.py but that starts my globally installed rerun, despite me being in our venv:

❯ python -m rerun --version    
DEV ENVIRONMENT DETECTED! Re-importing rerun from: /Users/emilk/code/rerun/rerun/rerun_py/rerun_sdk
rerun_py 0.8.0-alpha.0

❯ python3.10 -m rerun --version
rerun_py 0.7.0

(my total knowledge of how venv works can be summarized in an empty tweet)

[abey79]

@emilk TL;DR: it's likely that using python3.10 calls into your global Python install rather than your currently activated venv.

Long version:

AFAIK, and unless you recreated it, your venv is based on Python 3.8. When activated, your venv "provides" (by manipulating the $PATH) a python command that is a symlink to the interpreter used to create that venv. You can verify this as follows:

 $ which python
/Users/emilk/src/rerun/venv/bin/python
$ python --version
Python 3.8.x
$ readlink -f `which python`
/opt/homebrew/Library/Frameworks/Python.framework/Versions/3.8/bin/python3.8

(I'm making up that output based on lots of assumptions—yours will likely differ.)

In this case, you are using python3.10. If your venv was indeed created with 3.8, then it quite logically doesn't provide python3.10, which you can verify this way:

$ which python3.8
/Users/emilk/src/rerun/venv/bin/python3.8
$ which python3.10
/opt/homebrew/Library/Frameworks/Python.framework/Versions/3.10/bin/python3.10

As an aside: jumping between python versions is obviously a useful capability for python package devs, but manually creating venv for each version is annoying. A tool like Poetry (which would have to be alongside maturin in our case) helps with that, as it helps managing multiple dev environments (+ lock files, etc.). I'm using it for most of my projects. (Note that tools like nox (or tox, etc.) actually don't help on this front, as they focus on one-shot, clean venvs for test automation, etc.)

[emilk]

God dammit, I merged in main and something went really wrong.
I'm gonna rebase and force-push. Sorry.

[emilk]

examples/python/open_photogrammetry_format/main.py --no-frames is slightly less horrible now (at least after manually resetting the space views)