Lollipop Mapping

| 2 Comments

monopoleUVTop.jpg
When you UV map a sphere, you normally expect distortion at the North and South poles. If you preprocess your texture map in the right way, you can hide the North pole completely, at the expense of an "extra bad" South pole.

Think of it as wrapping paper over a lollipop.

pebbleTexture.jpg
An un-prepared image wraps around a sphere in Maya as expected.

normalUVSphere.jpg
With the usual North and South poles.

pebbleTexture2.jpg
Use Photoshop to "pre-distort" the texture map. Choose filters > distort > polar coordinates. Be sure to choose the "polar to rectangular" option.

monopoleUVTop.jpg
Now you have no North Pole!

monopoleUVBot.jpg
...at the expense of an "extra bad" South Pole -- which you can hide either through careful choice of camera angles, or through the use of a second, upside-down texture map, carefully merged (at the equator) with the first map, so that the end result is a sphere with no visual poles at all.

UPDATE 4/12/2009:

The pebbled concrete texture used in this blog post is available at higher resolution on flickr at this link.

2 Comments

I've created a tutorial some time ago that goes through the process of doing both poles - Sherical Mapping Tutorial. In my case I flip the map to do both poles and then clean up the seam if needed.

That's a good tutorial.

...It also serves to remind one that a spherical texture map also has many uses when the sphere is large and the viewer is inside it.

Leave a comment

About this Entry

This page contains a single entry by published on December 27, 2004 12:43 AM.

Telephoto and Wide-angle Lenses was the previous entry in this blog.

Discrete Tiled 2D Noise is the next entry in this blog.

Find recent content on the main index or look in the archives to find all content.