Creating UV Map

• A UV map is an image where every colour represents an X and Y coordinate in screen space.

When you create a UV map it will look like this.

A standard UV map generated

A UV map but has a blue channel.

The Two image may look very different but if you look at the red and green channels, they hold the same X and Y coordinate. The only difference is the bottom image has a blue channel with a value of 1. This does not effect what the UV map image does.

Creating a UV Map:

Option 1:

1. Create a Ramp set the channel to RGB and untick green and blue.
2. Then set point 0 parameter both X and Y to 0
3. Then for Point 1, X right click and click add expression and type width (this will grab the incoming width value and if there is no incoming image it will default to the root format.)
4. Then for Point 1, Y Set that to 0
5. Should look like the image below.
6. Now Create another Ramp set the channel to RGB and untick red and blue
7. Then Set Point 0 parameter both X and Y to 0
8. Then for Point 1, X Set that to 0
9. Then for Point 1, Y right click and click add expression and type height (this will grab the incoming height value and if there is no incoming image it will default to the root format.)
10. Should look like the image below.

Once you have created it simples merge with a plus operation and done.

Option 2:

1. Create an Expression node
2. Then type the following as the image below and done.

For More information:

• Demystifying ST Maps - Ben McEwan
• Understanding UVMaps – Warping with STMap (Part 1)
• Understanding UVMaps – Warping with STMap (Part 2)
• UV Map Expression Example