Solar system in Dynamo

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@Marcel_Rijsmus gave me an idea to make a solar system in Dynamo…

I know this may sound a little stupid but I didn’t quite realise the scale… I thought, “lets scale it loads and it will work”… Well, it doesn’t really.
The distances are so huge that the planet sizes just become dots (so I unplugged the spheres).

I got bored after mars and didn’t add any moons but it’s slightly fun to watch for 20 seconds.

Maybe someone can suggest how I could improve it.

SolarSystem

Gif shows planets orbiting without the orbit showing and then with the orbit showing.
I colour coded it: Mercury is grey, Venus : green, Earth : blue and Mars is red.

Dynamo file attached.
orbit.dyn (80.2 KB)

EDIT: Sun is wrong size in that. Should be 695508 Km.

I’ve tried making the planets and sun larger by a factor of 10 compared to the orbit distances but they’re still showing as points.
I tried doubling that too, and still just points…

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might be fun to calculate lagrange points or model the Roche potential as a surface ?

Lagrange point - Wikipedia

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I like the idea, but wouldn’t be surprised if the 1:1 scale of your model causes issues for Dynamo. Don’t forget that a sphere, being round, can be an object which needs a huge amount of facets/triangles being displayed, so that it looks “round”.
And now imagine how many triangles Dynamo would need to compute and display for a 1:1 scale planet?
Have your tried downscaling your whole model to a “reasonable” size (like meters), to see if the display works then?
Just my 2 cents. :slight_smile:

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It’s not 1:1
It’s something like 1000Km = 1mm
The issue is that the distance between planets is so vast, like vast beyond vast that the planets and even the sun appear as dots when I get the orbits on screen. If I scale them up by a factor of 10 the planets are still dots and the sun is a very slightly larger dot (at mars but a dot beyond).

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its not exactly on your doorstep, but over in York there is a scale model

Cycle the Solar System - School of Physics, Engineering and Technology, University of York

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image560×625 11.3 KB

if you compare the scales you can see the scale for distance and scale for diameter are different

maybe introduce a slider into your graph so you can find the best relationship between the two scales

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The issue is still about overall scale of the display.

To scale up Mercury to be large enough to be visible it’s no longer distinguishable from Venus… I think the Powers of Ten video from the Eames sums up the issue best:

Notice how to even see the sun they stop showing the earth and instead show it’s path around the sun (upscaled twice no less), and by the time we see the full solar system we can no longer distinguish earth’s orbit from the sun… and they are very much playing with display scales here.

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I knew the distances were vast but honestly I had no clue actually how vast.
Interesting that building something for fun as an adult can be very educational too. :smiley:

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You ever heard of AU (Astronomical Unit)

Makes a lot easier i think
Then with a slider increase the size of the planets till they become more visible (doesn’t have to be real size).

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I have yes. But I was hoping I could do it all to a real scale and not have different scales for planet size and distance from sun…

I naively thought I could zoom in.

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Thought provoking never the less
It is a fun challenge

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image1100×1361 179 KB

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I used three scales for the sun diameter, planets diameter, and planet orbits

/* use number sliders or enter scale values as below */
sun_scale	= 2;
orbit_scale	= 0.2;
dia_scale	= 200;
//*/

sun_dia_mkm	= 1.392;
sun_dia_skm = sun_dia_mkm * sun_scale;
sun_sphere	= Sphere.ByCenterPointRadius(Point.ByCoordinates(0, 0, 0), sun_dia_skm);
names		= ["mercury", "venus", "earth", "mars"];
orbit_mkm 	= [58, 108, 150, 228];
orbit_skm 	= orbit_scale * orbit_mkm;
orbits 		= Circle.ByCenterPointRadius(Point.ByCoordinates(0, 0, 0), orbit_skm);
dia_kkm 	= [4.9, 12, 12.8, 6.7];
dia_mkm		= dia_kkm * 0.001;
dia_skm		= dia_scale * dia_mkm;
random_seed = 5.5;
randoms 	= Math.RandomList(4,0,1,random_seed);
position 	= Curve.PointAtParameter(orbits, randoms);
planets		= Sphere.ByCenterPointRadius(position, dia_skm);
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