Making a complex UV texture

A friend saw me working on a model of a spine. I tried to explain how I created the UV textures. I was not very clear, so I put together this tutorial for him.

1. A complex object is hard to texture map. None of Lightwave's mapping types will allow easy texturing of the object.

2. An Atlas UV map is not helpful because the atlas map breaks up the UV texture into too many complex pieces, making the texture hard to understand.

3. Since this object is symmetrical I deleted half of it. In the end I will mirror the right half. This will make texturing a little easier. I will only have to create the texture for one half of the object.

4. I planed in my head how I wanted lay out the UV texture map. The ideal texture would be one that unwrapped the whole object in one piece with one seam in a hidden area. This object is to complex to allow that. I tried to choose logical regions that could be made flat without too much distortion also tried to minimize the number of pieces. The more pieces there are the harder it is to hide the seams between them. I colored each area with a different surface.

5. Create a morph target for the object. In turn, I cut each surface out of the object and pasted it back in, breaking the object up into distinct pieces. Working on the morph target I moved each piece away from the rest. (The base object remains untouched.)

6. Using the various modify tools, I shaped the pieces to approximate flat planes and rotate them to face the Z direction. I arranged the pieces as efficiently as I could to fit into a rectangle in the back view.

7. I created a UV texture using planar mapping on the Z-axis.

8. Adjust the points in the UV map to make sure each polygon has an enough space and that none overlap. You can also overlap polygons that will share the same color. For example the rectangle in the lower left of the UV map is an overlap of the 16 polygons the form the four holes that punch through the object.

9. I exported the UV texture as an EPS file (using the export EPS plugin). I have assigned this tool to a function key. I am not sure where you will find it in your setup.

I used the EPS file as a guide to paint the UV texture using Adobe Illustrator and Photoshop. In Photoshop I covered the edges of the polygon regions with a stroked lines of a uniform color. I then blurred the stroke slightly. This prevents the seams between different polygon regions from being visible when the texture is applied to the object.

10. The last step was to mirror the right half of the object to fill in the left half. Delete the morph target and merge points. (If you don't delete the morph target then the points along the object seams will not merge.) I assigned a single surface to all the polygons that make up the object and textured it using UV mapping to get the final painted object.