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Author Topic: "Sphere" Improvement Needed  (Read 2070 times)

Gregory

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"Sphere" Improvement Needed
« on: May 13, 2016, 06:24:22 AM »
So, the planets are rendered as much more spherical than in the old versions, so that's good, but when viewed from the surface, when clicking "C", you can see the pointy facial edges, which indicates they're not quite round enough.

Spheres on computers are rendered as polyhedrons with lots of faces, and with more faces, the shapes look more "spherical".

However, the planets are a bit "underspherical", as in they don't have quite enough faces.

If you go onto a modeling program such as Blender, and click on a "UV Sphere" or "Icosphere", you see the numbers of segments, they show you the bands of faces on the polyhedrons.

The "Segments" shows you the longitude bands of faces, and the "Rings" shows you the horizontal bands of faces, the default value is 32x16.

And as indicated, the value for the "spheres" in the old US, is 48x48, using that stupid 1x1 ratio, when they should've used the 2x1 ratio for more uniform accuracy, yet the default bodies that are small use 12x12 divisions, using a 1x1 ratio.
Thank goodness the "spheres" on US2 use the 2x1 ratio.

Unfortunately, with the degree of "jaggedness" of the surface, the Stars, Planets, and Moons seem to use the 256x128 value, while that's a lot, it's not quite enough, it's actually a bit below the threshold of when things appear spherical to all standards, the 360x180 value would be just right, as each face would only cover up 1 degree of the surface volume, and since a circle is 360 degrees in circumference, a "sphere" with the 360x180 division value would be at the threshold of roundness, and it would meet up to spherical standards, so with the 4 digits used in the program, the bodies should use either 512x256 or 1024x512, yet 360x180 would be the good minimum for sphericity of bodies, once you go up to and past 360x180 divisions, you can no longer distinguish them from a perfect sphere.
Yet this is a problem with the sports balls, the Pool Balls have a 32x16 division value, and the other sports balls, including Basketballs, Baseballs, Golfballs, and Tennis Balls, have a 64x32 division value, which isn't enough, so even those should use at least a 512x256 value, 512x256 is just the least needed, higher values are a good idea for "spheres" especially, so "spherical" bodies such as stars, planets, moons and sports balls should have more faces, by either 512x128 or 1024x512, as that would be better, 256x128 isn't quite enough.

32x16 = 512 faces, 64x32 = 2048 faces, 128x64 = 8192 faces, 256x128 = 32768 faces, 360x180 = 64800 faces, 512x256 = 131072 faces, and 1024x512 = 524288 faces, so the planets have 32768 faces.
131072 or 524288 faces would be better, and should be implemented in the next update.

If you don't understand the divisions, then go download Blender (if you don't have it yet), and when installed, open it and click on the "UV Sphere", and you'll see the division value on the 2 boxes on the left.

Here's a screenshot of the "undersphericity".

So I hope you think about that.
« Last Edit: May 14, 2016, 01:21:38 AM by Gregory »

Dan Dixon

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Re: "Sphere" Improvement Needed
« Reply #1 on: May 13, 2016, 07:21:08 PM »
Thanks for pointing this out.

Everything in US1 is my fault... and you can thank Georg for making the spheres better in Universe Sandbox .

We'll be redoing many/most of the human scale objects over the next few months now that we have a modeler on the team:
http://universesandbox.com/blog/2016/05/new-models-alpha-19/

Universe Sandbox is in active development... so look for more improvements soon.

Gregory

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Re: "Sphere" Improvement Needed
« Reply #2 on: May 14, 2016, 12:11:59 AM »
You mean "spheres", there should be quotation marks on each side of the word, because they're not true spheres, and only appear spherical from a certain distance.