View Full Version : Unwrapping a sphere

01-22-2007, 03:23 AM
Does anyone know how to unwrap a tesselated sphere, as i need to create a UV map where all the triangles are equal in the UV map and not stretched or different sizes.

I know that once the sphere is flat i can then create a planar UV in the Z axis, but how do i flatten the sphere in the first place???

01-22-2007, 03:36 AM
You will have to unwarp the sphere into a lot of stripes to get the triangles unstreched.
You can use the PLG UV Tools (search at flay). Let's you select the edges where you are willing to split the sphere.

01-22-2007, 06:42 AM
this script:

GreatBox (http://www.newtek.com/products/lightwave/tutorials/uvmapping/uv_mapping/clean_uv/clean_uvs.zip)

found in this tutorial:

Clean UVs (http://www.cgsearch.com.cn/english/cached.jsp?idx=0&id=78829)

may help. i've used it to get non-distorted uv's all the time.

01-22-2007, 08:18 AM
Thanks guys. I am a Mac Lightwave user so the PLG UV script on Flay is Intel only; and i will try out the clean UV tutorial.

01-22-2007, 08:28 AM
There should be a mac conversion on the PLG web page as well, but I've heard it's a bit flakey, but you might want to give it a go.

01-22-2007, 09:15 AM
If you use the PLG tools, there's a UV packer with it which rescales each uv poly to its relative correct size.

01-22-2007, 09:40 AM
Nice tutorial, a few quick shortcuts:

1) no need to write down the numbers from the info pannel. You can right click and select copy. MAC is what, option key?

2) No need for a script either - allthough it is nice. All you have to do is create the box and then go to Absolute Size for the box,(independent mode) right click in the X and Z axis and select paste for each.

Instant box that would have saved about 6 steps to that tutorial with out-of the-box LW Modeler tools.

Although you could just run the script. :) Just knowledge for future ref.

I have not tried that Japaneese plug in yet, but I enjoyed this tut, so thanks.

01-22-2007, 10:34 AM
I know that once the sphere is flat i can then create a planar UV in the Z axis, but how do i flatten the sphere in the first place???

You don't need to flatten...

Sorry I didn't found this earlier:

One of the most wonderfull uv tools inside lw is the "texture guide" tool (map->texture->more...(I don't think I've changed this in my layout))
It uses the standard texture projections to unwrap your object,

(it even tries to use the values of the first color texture layer coordinates of your current selected surface.)

01-22-2007, 11:50 AM
Page 357 in the LW9 Modeler PDF

Texture Guide

This command allows you to interactively create a UV Map for selected polygons.

Thanks for that tip!

01-23-2007, 04:35 AM
If you don't need a layed out map, where the triangles align edge on edge you can use the "Polygon normal UV's" command (under map->texture->more->polygon normal uv's). You have to select all the polygons you want in the map and execute the command. All triangles have the right size in relation to each other, but they will be placed over each other.