openspace command convention

Quick note to self - when we want to use the built-in fadeIn or fadeOut commands, we can't use the name of the object as seen in the info tab - like Scene.Moon here,

We will get errors like
Error when calling script 'openspace.fadeIn': Could not find property 'Scene.Moon.Enabled'

Checking the script log, we need to append .Renderable to that name, like

openspace.fadeOut("Scene.Moon.Renderable", 5)

Edit - Note: All of the above were with respect to the 0.21.x version. In version 0.22, things may change - for eg this commit.

tumblerd prevents disk from being ejected on Linux

When trying to eject a USB external disk, a message along the lines of "process tumblerd is currently using the disk, eject anyway?"

https://duckduckgo.com/?q=what+is+tumblerd+which+is+keeping+disk+from+being+ejected+on+linux&ia=web

Since I had a very large number of images on that drive, and I had just saved an mp4 file onto the drive, tumblerd was probably creating thumbnails for all of the multimedia files. So, did 

killall -HUP tumblerd

and then the disk could be ejected.

OpenSpace session recording "save frames" crash

On my Lenovo ThinkCentre M93 machine with an NVidia GTX1050 graphics card, OpenSpace session recording playback with "save frames" was crashing after a few hundred frames being saved. Each frame was taking around 1000 to 1500 ms for 4096x4096 frames.

According to Claude.ai, the crashes might be due to CEF "being starved" between updates - and I submitted this fix as an issue on the OpenSpace repo.

Claude suggested workaround was in SGCT.

// sgct/src/image.cpp

png_set_compression_level(png, -1);  // changed to:

png_set_compression_level(png, 1);

As the comment just above that line says, -1 sets the compression level to default, which seems to be 6. Setting this to 1 made the frame export only 300 ms per frame (3x faster) and also fixed the crashes - so CEF was not "being starved" of updates.

The increase in file size was not much, 4 MB increased to 5.1 MB for a typical frame.

Another change I made before exporting again, was to close all other windows and apps like the Edge Browser, which I had used earlier for triggering the exports - now OpenSpace has some checkboxes in the export settings which allows us to hide the UI while exporting, so we don't need to trigger the export via a web browser.

Edit: No, the problem is not solved. No crash when saving frames for this recording, ts_003_moon_to_Earth.osrectxt

but crashes after a few hundred frames when saving frames for this recording, ts_002_india_rotate_zoom.osrectxt

So my current workaround was to split the recording into multiple smaller recordings.

Edit - another workaround to get around the crashes, which seem to be caused by CEF, seems to be to disable the module CEFui inside OpenSpace > Settings - issue thread is at https://github.com/OpenSpace/OpenSpace/issues/3954 

downloading from a server via http (no SSL) with auth

Downloading some planetarium files from a server in Sweden, which had password protected directories but no SSL (no https) - 

1. Directly downloading via the browser - slow, prompts us to "Keep" or delete the file every time due to being downloaded unsecurely
   
   
2. Using aria2 - 
   
    aria2c -x16 -s16 --http-user=USERNAME --http-passwd=PASSWORD url
   
   Need ProtonVPN, since without it, http downloads are severely throttled to less than 100 kbps.
   
   
3. Better option, running 
   
   aria2c -x16 -s16 --http-user=USERNAME --http-passwd=PASSWORD -i urls.txt
   
   on one of our AWS servers - all the URLs get downloaded in a jiffy, then we can use Filezilla and download to our local machine over sftp without throttling issues.

github 14 day traffic stats

Since github has a page which shows 14-day stats, like https://github.com/hn-88/OpenSpace-AppImage/graphs/traffic but which is behind the login of the user, I asked Claude to create a stats page for the traffic to all my public repos. The prompt is here, 

https://github.com/hn-88/hn-88.github.io/blob/master/stats/prompt.md

and the github traffic stats page is here

https://hn-88.github.io/stats/

The "clones" number is so high for the https://github.com/hn-88/OpenSpace-AppImage/ repo because of the multiple daily build workflows.

adjusting sound volume on Mac

Since I don't have an Apple keyboard, adjusting the volume on the Mac mini was not very straightforward. An LLM's advice seemed to be a bit sarcastic when taken in the context of how easy it should be versus the method suggested - 

Adjusting the volume using the menu bar is a simple and straightforward method. Here are the steps to follow:

1. Click on the Apple logo in the top-left corner of your screen.
2. Select "System Preferences" from the drop-down menu.
3. In the System Preferences window, click on "Sound."
4. Go to the "Output" tab.
5. Drag the volume slider to adjust the volume level.

On my machine, it was "System Settings" and not Preferences. And, there seemed to be a slightly faster way, which is clicking on the "Control Centre" in the menu bar - screenshot below - the "edit controls" button allows us to drag the icon into the menu bar, too.

interesting - No-AI chatbot

Interesting to see how chatbots can be programmed manually, without any AI - https://p5js.org/tutorials/criticalai4-no-ai-chatbot/

Via https://p5js.org/

Via https://github.com/hedbergj/sims-dev/blob/gh-pages/expanding-universe-2/index.html

using Blender to mask bright scenes

Using the same technique as in this previous post, but running on Blender 5 on Mac Mini, 3840x2160 video for Unseen Earth was being rendered at around 15 fps using the ProRES LT codec. Apparently Blender still doesn't have GPU accelerated output codec support, and this is one of the fastest codecs as suggested by ChatGPT. The ProRES LT can then be re-encoded as HEVC using the py-ffmpeg-warp presets. 

Some more tweaks used were:

• Multiple masks one atop another to darken extremely bright areas,
• Using Shift-D to duplicate and then K to cut the mask
• Using an adjustment layer to increase contrast for the base layer. 

close all Finder windows on Mac

It looks like Option+Cmd+w is the keyboard shortcut to close all windows of an app. Also, Finder has this method of Option+click on the File menu, which then shows a "Close all" menu item. 

A bit clunky in my opinion. And apparently many people moving from Linux/Windows to Mac have this problem, due to selecting a large number of files and hitting "Get Info..." like I did - MacOS then proceeds to open that many info boxes instead of showing a single window with cumulative info as on Linux/Windows.