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map of earth on material (sphere) is distored - Why?
OK, I want a sphere with the standard NASA unwrapped image of earth, that you can find everywhere - for example this one
I'd like to do other planets too. These images are in a 2:1 proportion.
When I attach this to a standard material as the albedo map, the result is very distorted - the poles are just tiny (Antarctica for example.)
There seems to be no way to make this thing map properly, and there is just zero documentation or information I can find on how unity maps to spheres so that I can get it to look right!
I cannot be the only person who has ever tried this before...
So, how in the world does Unity's spherical mapping work, and how to create a texture image that will properly map on a sphere?
Seems to me that any such texture will properly map if you set the UVs up right. You'd need to know what projection was used to create the image. I think the place to start would be to research things like $$anonymous$$ercator and Peters projections, the setting-up is going to be easier for some projections than for others. But I dare say someone else will be able to provide much more concrete advice.
Well, it seems they changed the UV map and mesh structure of the default sphere mesh. I don't really understand why they have choosen such a strange alligned unwrap (at least for the top and bottom part): UV set 1 UV set 2.
The new sphere mesh is made up by a cube mesh which has been spherified (an old project).
The "old" sphere mesh (can't remember the version of Unity) has a quite nice equirectangular projection except the center vertex at the poles where merged to the center of the upper / lower edge. This was made with the "old" default sphere mesh of Unity and i used a similar image.
So like @tanoshimi said you probably have to use your own sphere mesh with an appropriate mesh layout and UV.
Answer by tanoshimi · Apr 24, 2015 at 11:53 AM
That's an equirectangular projection. You can't apply it to the standard Unity sphere, but it's trivial to setup the appropriate UV map for a sphere primitive created in Blender, say. See http://www.enigmatoots.co.uk/#!unwrapping-sphere/cvnq , for example.
Hey many thanks to you all.
Sure it's trivial, but it does require many clicks before you can get a mapped model into unity.
Seems strange that they would choose an underlying representation for this fundamental primitive object that would make more difficult to map to.
@Flash$$anonymous$$don: As i said above, the old sphere mesh had an equirectangular topology and UV-unwrap. Now it's not a cylindrical projection anymore. The mesh topology now represents a cube mesh, but the unwrap is still layed out like a cylindrical projection but with messed up proportions.
I have no idea why they switched to this sphere mesh. I would say the old one was more versatile.
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