Projecting world into sperical segment


I want to project a rotating earth on a transparent sperical segment. I use a patch that came with the demo of vvvv last year. rotation and everything works fine.

  1. I think I must project my renderer output onto a 3d world in v4 . right? where can I find a simple mapping example?

  2. my earth rotates in the x direction. (actually i ignore the tilted earth axis) Now, the user can use a slider to shift the earth between the booth polar ice caps. When I change the z rotation I must also change the y rotation to get the effect the user expects. is there a mathematical description anywhere to do this?


Use map node to map the slider value to the rotation of the sphere. You may also add a rotation node to transform node to have desired tilt. Can you please explain a bit more if i get it wrong?

after a few days off i will try it again…

I want to map the world globe on the spherical segment, the real projector is positioned behind. how do I position the virtual projector? inside the world?

do you think of something like this projector-(ex9.effect) ??

no, i have real spherical segment, i will project a real world (or that part of it) into this transparent sperical segment.

by the way: the effect ist very cool!

Use projector node as indicated and use clockwise culling for the spherical segment

i put the projector behind my earth.
can i use a full 3d sphere for my earth? I think it should be possible to crop the segment with the near and far pane of the projector?!?

or should i make a real segment.

sorry for my stupid questions, I’m totally new to mapping.

With the clockwise culling you should be good to go as the front facing part would be invisible and you would only see the inner side.

where can i define the clockwise culling?

cull node

thank you, i got it.

now i map my trackball movement to the earth.