Spring RTS Engine

Erm... I have a need for a uvmapped sphere. It needs to be absolutely perfect, without any gaps in the skin- even a 1-pixel gap will be visible to players, at the scale they'll be viewing the object. It's OK if it's distorted on the poles, but I don't want a visible seam line.

... and I'm stuck. Like, really really stuck. I've tried modeling this thing with Rhino, Wings3D, UVMapper Pro, etc. etc. etc., and everything I use seems to create a seam! I just don't get it! There must be a magic way to get it to not have a visible seam, but I just can't figure it out, and it's driving me nuts. Polar distortions are fine and dandy, but if I can't get rid of the seam, it's not worth putting the oodles of time into making the skin! I've seen plenty of spheres like this in various games- obviously, the pros know how to do this. Are they just faking it really cleverly, or is there really a way to get this done?

In maya, you get something like this.

With the left sphear and the upper uv map as the default.
The right sphear and the lower uv map with the spherical mapping. (Which I don't remember distoring so much)

There is a seam because there is no way to unwrap a closed surface without creating a seam (this can probably be proven mathematically). All you can do is paint the texture in a way that hides the seam (that's what everyone else does). If you have an unwrapping like Zenka's there you can try painting it like a tiling texture, there's plenty of tutorials on how to hide seams like that.

But then you have overlapping UVs..

depending on what he needs that might not be a bad thing.

Large sphere + What Argh's current project is...

I can only think of one thing in that universe that is large and a sphere... please tell me you're not making that...

lol...

smoth wrote:map half a sphere, mirror it, freeze. IIRC, That should give you what you want.

Smoth speaks truth, I was gonna say it but i smoth beat me to it. I can chuck one your way if you want it.

Guessmyname wrote:Large sphere + What Argh's current project is...

I can only think of one thing in that universe that is large and a sphere... please tell me you're not making that...

A huge apple?

I'd say you should mirror it (as it was mentioned twice) to get rid of any seams and use either the top or lower UV mapping solution. The lower one clearly has less distortion.

A good way to hide seams is when you are drawing on the UVmap image make sure
that the drawing is about 2 pixels larger then the UVmap.

You can do that by selecting the UVmap image then modify the selection by expanding it by
2 pixels, then make a new layer and use the paint can to fill it in with a solid color.

Then just draw on the new image, there should be no seam after that.

This gets rid of nasty outlines especially on the mip maps, I think argh is doing this.

Guessmyname wrote:Large sphere + What Argh's current project is...

I can only think of one thing in that universe that is large and a sphere... please tell me you're not making that...

OMG

Epic Death Star win!

Why don't you try ripping the model from whatever sort of game that uses it, and looking at the uv map from that?

P3374H wrote:

Guessmyname wrote:Large sphere + What Argh's current project is...

I can only think of one thing in that universe that is large and a sphere... please tell me you're not making that...

OMG

Epic Death Star win!

Why don't you try ripping the model from whatever sort of game that uses it, and looking at the uv map from that?

Because that would be immoral, Peet.

This must be so confusing for those who don't know what we're talking about...

neddiedrow wrote:Because that would be immoral, Peet.

I'm not saying steal it, I'm saying looking at how it's done...

e: upon further research, some programs (I looked at a spaceflight simulator, Orbiter) use a seamless projection that distorts the texture somewhat. However it doesn't use the same UV map system that spring does, it just uses a mathematical formula to project the texture on the sphere.

Its not what your thinking, why would they have something that makes the map look like a pinhead in a game at visible sizes when other objects are supposed to be too large yet to scale would be miniscule.

That's what I was wondering, and thus why I asked

EDIT: Unless it's some minature one that I've never heard of that only appears in some obscure novel

?