Insomniac Games lead character artist, Gavin Goulden, offers tips for removing texture seams using ZAppLink with ZBrush and Photoshop...
When painting textures for your game character or prop, it is expected that your textures will be seamless, and that no UV seams within your model will be clearly noticeable. Though, if you are painting textures by hand, the 'old fashioned way', and not baking them from a high resolution source, getting the seams to disappear completely can be tricky. There are a few different ways to accomplish this, and a great way is to use the ZAppLink feature within ZBrush. ZAppLink will take a shot of your model, dissect its layers, allow you to alter the textures in Photoshop, and then reimport that information into ZBrush.
Painting out seams can be a painless process by using a few quick and easy steps with ZAppLink
Using the ZAppLink feature
Once you have a model imported into ZBrush with a texture applied (import a JPG or PSD version into your Textures panel and flip it vertically in most cases, then apply in the Tool > Texture Map panel), locate the trouble area. Once you have a nice shot of the seam in question, navigate to Document > ZAppLink. This will ask you to bring the file into Photoshop. Once the file is in Photoshop, you will not be able to alter the model, unless you want to cancel the process. With the file imported into Photoshop, it is important to keep the layer order intact. I like to just select the mask and paint within that – usually clone stamping areas or painting over the model manually. Once you are happy with your work, save the PSD and return to ZBrush. ZBrush will ask you to apply changes, accept this, and see your seams disappear! Once this process is complete, clone your texture and export it. This new diffuse texture will be your seamless, or seam-fixed, asset!
Access ZAppLink through the Document panel. Once you paint out the seams in Photoshop, fixing your seam is as easy as
Resolution and ZAppLink
An important point to make about using ZAppLink is that the results of the tool are based off of your model resolution. Meaning, a model with fewer points to transfer the information to will have weaker results than a model with multiple subdivisions. So, before using ZAppLink, be sure to subdivide your model a few times to make sure that your work is not wasted.
Keep in mind that the success of your texture projection is based on the density of your model
Check out Gavin Goulden's previous tips of the day...