Is there an empirical way to measure UV map efficiency?

Jackson31

One of the aspects of 3D modeling I quite enjoy is trying to fit all my UV islands together to make a map with as little "white space" as possible.

This made me wonder if there is a program which can empirically measure the ratio between UV island covered area and empty space?

It would just be nice to know my UV map has 85% coverage, for example

monster

http://portfolio.juantwo.com/maxscripts.html

I've got a MaxScript named Texture Area. Not sure which program you are using.

Fwap

A more tedious way would be to render your UV map with your islands filled with solid white.
Blur average in Photoshop, and use the color picker on the averaged color out of your hue saturation and brightness, your brightness box should tell you what % of the UV space you are using.

.Wiki

UV Layout displays the coverage of the uv map after packing.

EarthQuake

perna wrote: »

Just to weigh in on this. While it's a fun puzzle to muck about with, the end result of super-tight packing tends to gain less than efforts to reduce number of seams and make the map easy to figure out and work with for the texture artist (efforts which will tend to decrease the packing efficiency). It's the texure artist that creates the end result, so the easier you make his life, the better the end result, even if less sharp.

Additionally, those who go for maximum UV coverage also tend to randomly scale up pieces so they'll fill the empty spaces better, causing inconsistent texel density which brings out seams and generally hurts the end result.

+1

Less seams will also result in less vertex use as well. Super tight packing has another drawback, if you don't leave enough space between your UV islands you will get seams/artifacts as your textures mip down. Consistent texal density is also extremely important, its better to have consistent detail than to use all your space but have one mesh chuck with 2x the pixels as another.

So while its important to have efficiently packed uvs and not have excessively wasted space, there are many other factors to consider as well. A wasted space % number may be useful to see if you're really off the mark, but it won't tell you if you have a good layout.