Tutorial for Repainting UVs with Transparency (Unwrap 3D Pro)
When repainting UVs, you may encounter models that use texture transparency, such as leaves on a tree.
In fact, your model's UVs may be assigned to, not just one, but many texture channels (diffuse, opacity, bump, etc...).
As a result, all channels must be repainted. This tutorial will explain how to repaint UVs with transparency.
As an example, let's say we would like to repaint the UVs of a leaf texture. This particular texture was provided
as a PNG file with an alpha channel:
To use this file in Unwrap 3D, we can load the PNG file in both the diffuse and opacity
channels. In the Opacity Map dialog, make sure the Use alpha channel option is checked.
To demonstrate repainting UVs, we will first copy UVset1 to UVset2 using 2D Tools | Copy UVsets.
Then, switch to UVset2 by clicking on the 2 button on the main toolbar. Finally, we will scale the UVs down to one corner:
Now, click File | Export | UV Map. Set the color type to Repaint. Under Repaint Options,
set the format to 32-bit. When 32-bit is selected, Unwrap 3D will export a 32-bitmap, using the opacity map as its alpha channel.
32-bit formats include BMP, TGA, PNG, and PSD. For this example, we will export the repainted texture as PNG:
Let's take a closer look at our exported UV map. If you load the repainted PNG file into Photoshop, you should see a familiar transparent background.
As you probably know, Photoshop has a quirk of converting the alpha channel of PNG files to alpha transparency, but this is ok for our purposes:
That's it! If you have any other questions about repainting UVs with transparency, please let us know.