I’ve seen a lot of discussion about the Decal Workflow popularized by games like Star Citizen and Alien Isolation. This method for creating environment assets uses weighted normal data in its modeling is appealing for its ability to iterate quickly and get strong results while using far less texture space than if one were to bake out everything. It is also nice to be able to “float” decals and place minor accent shapes wherever you want.
There has been a problem however in that this process doesn’t give you as much freedom as one would like. In Unreal there are limitations in how decals can be used, namely the inability to blend materials from your decal sheets. There have been many requests for Unreal to expand its decal capabilities. People have gone as far as to generate custom engine builds for workarounds to this end. Furthermore, this process tends to give you a very sharp, clean look in which limits the cases this workflow is good for. I’ve seen a lot of Sci Fi corridors and such that are beautiful… but could use some grunge.
Below is an example of a method of asset creation which allows for the same freedoms of the Decal Workflow, but with all of the sweet sweet material blending. Also notice how the floating details have seamless edge wear and dirt collection. This is done using two UV channels rather than decals. There is a simple decal on this box, but all of the other knick-knacks are placed using a primary UV channel, while the rest of the material is placed in the secondary UV channel.
This method works with Unreal (also Blender, Max, Maya) right out of the box and is very efficient for both iteration time and overall memory consumption. If anyone is unfamiliar and would like to know more about this, please let me know and I’d be happy to answer questions.