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