Real Scale Solar System lighting test

Hey guys.

I was curious what if I try to model Earth, in real scale, and try to light it with the Sun, also with real scale.

So. I assumed that 1 blender unit is 1 meter. So i have created an icosphere with a radius of 6 000 000 blender units, or 6 000 km. I have changed the camera cliping max distance to 1 bilion km ( 1 000 000 000 000 blender units ).

As you can see strange things happen to viewport when the sphere is 6 000 km in radius.

But i wantet to see if any glitches are visible after rendering. So i have created a sun lamp, in a real distance from Earth to the Sun, which is 150 milion km. (150 bilion blender units), and with a real size of the Sun - about
700 000 km radius (700 mln blender units).

This is what it looked like after rendering in viewport:

You can see that id doesn’t look very realistic. (by the way the Earth sphere has a simple diffuse material).

So i decided to delete a sun lamp, and create a real scale Sun as icosphere with emission material assigned.

As you can see, it’s looking very nice, no glitches. I will experiment with this a little more and see if I can apply textures to such a huge Earth mesh, and maybe still model a small 10m spaceship in orbit around it without glithes.

I hope you found it interesting :slight_smile:

You should scale everything, change the units from blender units to metric, and instead of using 1:1, use something like 1:10 or 1:100, than scale everything in this proportion, i understand you want “real” scale, but scaling down should’nt cause any problem as long as EVERYTHING is on the same scale. Also, how is the sun emit shader strength calculated?

I did this probably 20 years ago :slight_smile: But in different software. Using real sizes, I ran out of bounds with the coordinate system - I simply couldn’t model anything far enough out. So I decided to scale down everything (like, 1mm = 1km), which allowed me to model everything but now introduced shading errors on surfaces. Hehe, I even had correct speedups and slowdowns along the elliptic orbits (fast at perihelion, slow at aphelion, for all bodies and known moons at the time).

Fun little project, but I came to the conclusion that real relative scale wasn’t feasible. Having since learned more about how floating point work (trade-off between range and precision), I wouldn’t even have tried today. I’m not saying it won’t work in Blender, but I wouldn’t be surprised at all if it didn’t. You’re better off toying with things like Space Engine (models whole known universe) :slight_smile:

Jh0nny, this was fast test, i have experimented a little with the sun emission strength, setting it to 5 seemed fine.

CarlG, yeah, I know Space Engine, love it! But I’m thinking about making a sci-fi scene/animation in Blender.

The point is, i want to see if I can go with real scale solar systems and still have details on the spaceship like 1mm.

1 Like

I just uploaded a couple of test anims from the stone ages (10-20’ish years ago):

Except I put together the frames of the first one in Blender today as I actually had them still around. Fun times :slight_smile:
Keep in mind, rendering back when wasn’t the same as it is now. Saturn texture (except in last, image used) is procedurally animated. No UVs, just tangling with spherical projection coordinates.
I even have the shader code available. Unfortunately I’m no longer able to read my own setup :smiley: I wanted to try something similar in Blender now that I’ve finally figured out how to do spherical coordinates with nodes (wasn’t even that hard). I did this after failing with real relative scales though.

Oh my God CarlG! This looks awesome! I would love to be able to make a planet like this, because I’m working on a little sci-fi project. The atmosphere looks nice :wink: And the rings are great to! Almost like in the Space Engine :wink: