fisheye-foto on a hemisphere

[stephan]

hi ventuzians,

since several days i try to map a fisheye-foto on a hemisphere, see picture below.
Surely it's not a ventuz-specific theme.
Hemisphere is in motion, so the mapping should stay fixed on the sphere.
What mapping in texture-node?
Any ideas? Google was not helpful
I only expect a little hint, not a complete solution.

Thanks a lot for your answers

Stephan

leftside the sphere, rightside the original square-fisheye

[joschy]

take a look here: http://www.youtube.com/watch?v=OD_p9bTpbQ4

[stephan]

Thanks Joschy,

unfortunately no solution shown in this clip for my problem.
The job is to import these already existing rectangular square fisheye pictures (unchanged) in ventuz and then mapping upon the hemisphere.

Any ideas from other ventuz users?

many greet,
stephan

[Karol]

Hi Stephan!
I think you would need to model a hemisphere with the appropriate UV-coordinates. Ventuz does not provide such a geometry primitive so you have to do it on your own.
This hemisphere needs UVs in the range [0;1] to map the whole texture!

Cheers
Karol

[stephan]

Hi Karol,

thanks for answering.
I created this hemisphere in 3dsmax and import it in ventuz, this works fine (see pictures).
The following mapping in ventuz is my problem because the texture is not fixed when moving the hemisphere.

stephan

[Karol]

Ah ok!
You mean when you rotate the hemisphere the texture does not rotate with the object?
This behaviour is affected by the parameters of the Mapping 2D node. But with default setting this should work correctly.

Karol

[stephan]

Exactly Karol,

but I tried all possible mapping constellations with no success, so I quit my attempts and asked the forum.

Thanks for your efforts!
stephan

[Karol]

Could you post a simple demo scene (Archive VZA) so we could take a look inside your scene?

[stephan]

little demo shows my problem.

greets from stephan

[Karol]

Hi Stephan,

your hemisphere does not have the correct UV coordinates!
First of all the pole of your hemisphere must have the UV coordinate [0.5;0.5].
And the UVs on the 'equator' must be such that none of the black fisheye-image region is mapped to the model.
I don't know if the 3D content creation tools can calculate such UVs. Probably you need special software.
Btw. a very interesting web-page for such stuff: http://paulbourke.net/dome/
A different approach would be to program a special shader but that's not that easy neither.

Karol