Hello,
I need to unwrap a sphere, texture it, print it on paper and stick it on the real sphere.
There is a problem with texture mapping. Its crapping at the center of the sphere.
Mapping is - Generated Sphere. Texture is the map of Moscow. Got to do globe of Moscow.
I understand that there is no way to unfold sphere texture without distortions, I want some less distortions at the top and at the bottom of sphere.
Maybe post processing will help? Don’t know what to do else. Showing to you people my .blend, some textures, some results…
Mark the sphere with edge seams along the vertical edges of the sphere, dividing it into a series of wedges, unwrap those wedges, bake your texture onto the unwrapped sphere, print, cut out and apply to the physical sphere.
Be sure the 3D-Cursor is at 0/0/0
Press <num 7> to be in topview
<shift>+<a> mesh>grid
change grid size to 32/32, 64/64 whatever you desire.
move grid +1 along z axis <g> <z> <1> <enter>
enter editmode in topview, select all <a> if not already selected, press <u> to unwrap select “from view (to bounds)”
press <num 1> for frontview, press <shift+w> type 180 <enter>
go to sideview <num 3>, press <shift+w> type 360 <enter>
press <w> select remove doubles.
You got a planar texture mapped perfectly to an UV sphere.
Tried to realize your method and realized that I already tried to do so.
In the end, when I making seams and unwrapping the sphere for the “petals” (for paper cut) I got to change texture mapping to Generated – Sphere. And I got same problem.
Doesn’t matter how I create a sphere. The problem is the mapping!
I cannot use Flat mapping for the sphere, because I lousing part of image in “dark” area of my UV.
I got to use Sphere mapping, but that method will corrupt texture at any case
I expect you will get the distortion whatever method you use.Whatever mapping you use, at some point the edges of the image will have to come together into one point, if the original image doesn’t take that into account (like most earth textures you download) you will get distortion.
What magic result are you expecting to see?
i think you try to do it with only 1 uv-wraping?
But you have to use 2 uv-unwraps.
One to map the image onto the sphere
and the second to bake this texture to the uv-unwrap to be used for cut and glue together …
Those are different.
The first depends what kind of image you use … maybe the tip above
for creating the sphere from an planar image.
But after this sphere creation you have to create the second uv-unwarp
to bake the texture in a way you can cut and glue together the parts for
a paper-made-sphere.
There was a thread about paper-models made with blender …
Certainly! We can’t map image right to the sphere without distortions. There is more than 50 ways of earth projection to the flat surface, therefore there is about 50 ways to map flat image to the sphere. Many scientists thought about unfolding spherical globe to flat map. I don’t need to invent anything!
I only want to recreate one of it:
i am not shure, but it looks like some want to solve a school-exercise (now there is a similiar posting again)
here is a screenshot,
the only wrong thing about it, thats clearly to see, i missed one first cut.
I made a plane with subdividing into 3511
but i should have used 3611, then the unwrap for
the paper cut would not be slightly bend.
To say it clearly, the first time i subdivided /unwrapped the plane and
then did bend it (shift-w) two times (the procedure is already told very well in this thread) to get it into a sphere, it did not come out with the 36 edge-lines to adjust
in the Mercator-projection from arktis to antarktis. (or did i use 35 subdivisions … ?)
Like i already said, there are 2 uv-unwrap - one for the mercator image to the plane,
and one of the warped-plane-to-sphere (but without remove duplicate vertices, they are good for the knife-cuts) unwrap with those “ball-leaves”.
edit: i had to rotate the uv-unwrap of the plane around 90 degrees to fit for the mercator-image.
i dont know what this image-sample should be good for … what purpose?
Shure, you want to project something onto a sphere-like object.
But you have to know what it is like.
Check the wikipedia entries about earth-mappings like
mercator, robinson, peterson, etc.
Check the already posted tutorial about creating a blue earth with
clouds etc. (link is in this thread …).
If you know what kind of projection your image is (this sample is handdrawn??)
then you can use this geometry to uv-map it to a flat plane (subdivide the plane).
And then you can (check the few steps …) create a sphere from this flat plane.
Then the last thing is to create a second uv-map unwrapping the sphere to a new empty (blank) image with seams (like shown in my sample screenshot). You bake the texture to this image and only need to print it out, cut it and let a bit parts for
glueing together.
So you need to know:
how to un-wrap a sphere to such a net.
how to bake a textured object to a image with a different uv-texture-map.
how to create a sphere from a flat plane.
how to subdivide the flat plane according the geometry of the image for the first texture.
You can practice/exercise every single step,
in the end, you need all.
And you can try it with a simple cube,
instead of a sphere for some parts of this.
Almost nothing changes.
