perfect UVs on a sphere ?

[cheeseburger]

Hi All,
can any one remember how to get perfect non deformed UVs on a sphere ? I always end up with distortion on the top and bottom and I can't for the life of me remember how to do this ...

Thanks
Cheeseburger

[ActionArt]

If it's just for rendering purposes, go with "implicit" rather than the default "explicit" projection.

[cheeseburger]

Hi ActionArt,
Thanks for your reply, but .... That only seems to be a MentalRay trick and isn't the one I heard of some time ago.
Apart from not the correct mapping in the view port, other render engines do not like it either. However we're on the right track. I remember there being a particular sequence to follow and it included Implicit as the last option and showed an almost perfect mapping in the viewport and in different render engines.
If any one remembers what it is ..... please help

Thanks

[ActionArt]

hmmm... I'm curious to know too.

[cheeseburger]

Yeah ....Dagnannit ! This should be a walk in the park for most folk around here lol

....... Help ........ Please

[oglu]

use a smoothed and spherified cube...

[cheeseburger]

Hi oglu,
Thanks for your reply
That doesn't seem to work unless you bump up the subdivisions until it's white with geometry.
Looks promising but doesn't seem to be practical

This is nuts Pro guys must need this at least once every day .......

Any other ideas ?

[Hirazi Blue]

This is nuts Pro guys must need this at least once every day .......

This can only mean:

• there are no Pro guys here
  or: this doesn't come up daily

Just performed one of my famous "I've got nothing better to do anyway"™ web searches and I am afraid I couldn't find anything useful relating to Softimage. I seem to recall something like this came up at least once on the XSIBase, but a search of the remnants of its archive I have on my PC turned up empty also, I'm afraid...
;)

[cheeseburger]

Hi Harazi !
I think that my original post on xsibase. Something like " UV sphere problem "
By the way ... No offence intended with the "pro" comment.
If you think about though this is such a simple thing and I'm sure that it must be used on a daily basis, no ?
Softimage has some stuff like this. Real simple everyday stuff that's hard or hidden or missing.
I digress ... What do you do ?
Thanks for the reply

[oglu]

do you use this for a realtime preview..?
let the render subdivide the cube...

[cheeseburger]

Yes, as well as for rendering.
I tried subdividing the cube with the + shortcut, but the spherical mapping still looked crap in the viewport ...

[Superpositivo]

I always use the method to leave the poles open, like a Nurb Sphere.

1 - Add a new loop of edge at the poles.
2 - Delete the triangle polygons of the poles.
3 - Scale down to 0.001 (not zero) the edge loops of the holes.
4 - Add a Uv or Spherical texture projection.

You'll have a perfect squared Uv just as the nurb one. Ok, It has the poles open, but they're so tiny, they shouldn't hurt that much.

[cheeseburger]

Ciao Superpositivo,
Thanks for your reply.
I'll try this ... but doesn't this seem crazy, that something so well used is problematic and you need a work around.

Thanks again ...

[gaboraa]

Yes I use the same method of deleting the pole triangles but sometimes spherical projection doesn't work and I use walk on mesh to create perfect square Uvs and and I add lots of edge loops at the poles for eliminating the pesky Uv distortions if you want your sphere low poly

[cheeseburger]

Hi gaboraa,
Thanks for your reply,
I can see the way this is going ... If no one else has an official type of solution then I guess I'll just have to make one these modified spheres and save it out as a new primitive.
Thanks again
Any one else got anything ?

UPDATE ... I asked a friend with 3d studio to send me a spherically mapped sphere and ... he did that and I got it in an email about 20 seconds later !
it looks perfect on first examination.

For Softimage I'll break it down into 2 separate uses 1 for realtime viewport sky scenarios and 2 for other model objects to be exported for work
Does anyone have any advice for realtime viewport stuff, as in cubic mapping etc(which I've never tried)
For general modeling purposes I'm going to feel like an idiot not having a simple solution ....
More help please ......

[gaboraa]

If you don't like the modified sphere idea, you can wrap a grid around a nurbs sphere using surface deformer with a planer UV applied to the grid. This way takes your seconds to create a sphere without pole distortion and I think this is more easy to create another deformed primitive because it will be a parametric sphere and it is more preferable to edit the uvs of a grid than a sphere.

Just create a grid and a sphere.
Add planar uv to the grid
Wrap the grid around the sphere using surface deformer
Done.

I do not have any other solution to this problem and eager to learn others workflows too.