The TYCHOSIUM 3D simulator


I’m currently working on the new Tychosium version and any opinions/ideas are appreciated. The first big job is to move all the existing code and functionality into the new framework/codebase and when that’s done it will be easier to build new features.

Some new things that will be implemented:

  • Planet camera - The ability to view the model from an Eartly view or from any planet.

  • Clickable objects - The ability to get information like Right Ascension and Declination for any celestial object by simply click or hover on it.

  • Nicer graphics and shadows so that Solar and Lunar eclipses can be shown.

All the best /Patrik

THE TYCHOSIUM 3D simulator:


Hi Patrik, thanks for the forum.

I went today on the online tychosium simulator and noticed the option to accelerate/decelerate a given time period was no longer available. I was wondering why, since I felt it gave much more control over planetary motions.

Hi Greg, we thought it was confusing and a bit overkill to have both the speed setting “One second equals” and the multiplier/backwards slider, so I replaced it with a reverse direction checkbox. This allows you to do about the same thing as with the slider.

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Hi Patrik, I personally thought the slider was one of the most useful tools of the simulator, and taking it out appears to diminish the user’s control.

If you were to work out the long term precession motion, you could accelerate up to 1 second = 4000 years. That’s no longer possible: eliminating the slider option has decreased the capacities of the simulator.

For each time period, you could change the speed by multiples between -4 to +4.

For example, for 1 second = 1 week, you could change the time speed to:

-4 weeks
-3,5 weeks
-3 weeks
0 (no motion)
+3 weeks
+3,5 weeks
+4 weeks

a total of: 16 different speeds for each time period, without counting the zero multiple. That’s a serious loss in terms of the simulator’s capacities.

In terms of interface use, I now have to click on run and 1 week, then click again on 1 month, etc. It feels as if overall control of the simulator motions is lost without the slider. It makes the runs more mechanical, more stop-motion instead of dynamic and interactive. The slider allowed the user to go back and forth around a point by clicking and dragging, while observing and focusing on the planetary motions on the screen. Now I have to click and focus on the tool bar every time and I feel that makes me lose focus. It interrupts the flow of experimenting.

I feel that’s a loss to the amazing quality of the simulator you designed.

edit: for clarity and further development

Dear Patrik, the other day I was actually thinking to ask you to reinstate the slider… As it is, I am also ‘missing it’ !:slightly_smiling_face:

Dear Greg, thanks for your welcome input and advice. In fact, I am probably to blame for the removal of the slider, since I often tend to ask Patrik to ‘keep the Tychosium’s controls simple and unclogged’ - but in this case removing the slider was, I agree, a bad idea.


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Dear Greg. Thank you so much for the feedback.The first thing I will do when I get working on Tychosium next week is to reinstate the fabulous slider :slight_smile:

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I’ve now reimplemented the slider, named it “Speed multiplier” and given it a range of -5 to 5

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Hello Patrik,

I was delighted to see the demonstration of the coming version of the Tychosium in the Grimerica podcast. Very nice work! Some reflections:

  • Consider using a picture-in-picture approach for the planet camera. As a user, I’d like to be able to move this floating window while keeping the outer-space perspective in the background. Perhaps even multiple such views from different planets/viewports?
  • Consider adding some camera/viewport presets for quick positioning of certain perspectives, e.g. the Earth-Polestar perspective. Maybe even allow the users to store their own perspectives.
  • During the podcast, you mentioned that you’d like to add shadows for the rendering of eclipses, but that the visual representation of planets and such makes it problematic. It may be possible to use a ”ghost core”, i.e. visually hidden object, of correct dimension just for the rendering of the shadows, while making the visible objects transparent in the rendering process. Just a thought.
  • Consider adding a calendar with important events, e.g. conjunctions, eclipses etc, that users could click on to set the time. This would facilitate any review that users as likely to conduct and it will help to demonstrate the many unfamiliar observations stated in the book, such as the supposed ‘non-periodic’ comets. As a user I’d like to be able to browse through a calendar and click on known events for a simple and quick visual presentation of such events.

Keep up the good work!

Thank you Per. Excellent suggestions. Often when developing you tend to not think enough ‘outside the box’ which can lead to tideous and unpractical solutions, so input like this is very helpful. As for the planet view, my ambition is to make it generic, so that any planet, not just Earth can be visited.

And split screen is something I will implement as well. It’s important to demonstrate that this model work both from a geocentric viewpoint and a birdseye view. Something a heliocentric model is not capable of without cheating geometrically.

And your thinking of having “ghost objects” is very interesting. I was thinking of doing some kind of scaling on the fly but it’s probably much easier to just have a prebuilt model in correct scale that becomes visible from a planet perspective and that’s used to calculate eclipse shadows. Will look into it.

I’m currently working on a new trace function and the ambition is to make it possible to hover the trails and see a date/time stamp with RA and Dec for the individual points that makes up the trails.

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