Could you explain how you made the custom grunge generator?
Amazing work sir! Congratulations
Billy Lundevall from Quixel talked about the production of awesome materials with the help of Quixel SUITE. Billy is a very talented artist, who works both with 2d and 3d art.
I work at Quixel and I do many things, I started out simply doing 3D art (actually most of the people at Quixel are artists), but my passion to improve the material library drow me more and more towards creating usable resources like materials and brushes. I am originally a 2D artist and I have been making my own brush libraries and usable resources since I first started doing digital art and doing the same thing for the Suite came very naturally.
My role is really quite varied however, and my tasks have ranged from making materials, making brushes, collaborating on assets with other artists, helping out with support and hanging out with the community, making tutorials and documentation to making promotional art and everything in between. Right now I am working primarily on Megascans, much like the majority of the Quixel team.
I have contributed to many games indirectly with the source material I have made and the features I have pushed for the Quixel Suite, but I don’t work with games directly. I prefer offline rendering solutions where I can add as much detail to an object as I want without the technical limitations that come with a real-time solution requiring 60 frames to be rendered every second.
I have to admit though, that real-time is starting to look pretty good. I might reconsider my position in this matter a couple of generations down the line, but for now I’ll just try to stay away from games whenever possible.
The Production of Materials
Creating a material starts with reference and research, and what matters the most is understanding how a material is built up in real-life, that is what usually sells it in the end. Accurate scanned values also helps. Ironically I have had very high use of the knowledge I gained while working as smith after graduating just to have a job. I learned a lot about how materials behave and feel when repairing heavy machinery, welding and manufacturing real things.
Before you start the software you need your model, preferably an ID map as well as basic PBR and Photoshop knowledge.
Elements that Define the Look of the Material
The key here is layering.
A material should have depth to it, both in the form of it’s actual construction components as well as in details ranging from large to small. Let us say you have a combat vehicle of any kind. It most likely will be made out of steel, that steel will probably have a zinc based coating for rust protection, followed by a paint job. This paint will be worn down into the metal by regular wear and damage, which will make the metal rust, making the rust something that should appear on naked surface metal and underneath the paint rather than above it, causing it to warp and bubble. Since this vehicle is still in use, some rusty painted metal won’t be enough to make it believable as it probably has taken some more fresh wear and damage, exposing clean steel through scratches and direct impacts that have scraped away the surface layers. And to top it of, this thing will most likely be dirty, both from direct exposure to dirt and from the accumulation of dust and oil/grease residue in narrow spaces and on mechanical parts.
This is the kind of thinking that is necessary to create a believable material.
Advantages of Additional Tools
The main advantages is being able to define global things, like edge wear or cavity dirt over an entire project with just a few clicks. Doing this purely with Photoshop would take considerable amounts time, even if you used some tricks based on baked maps. Especially since you need to define these things over several types of maps. I have done this, and I would never want to do it like that anymore.
Making Materials Unique
I don’t think there is anything that beats real world hands-on experience combined with building your own base library. Relying on the presets will probably look good in most cases, but in the end that just means that I have indirectly textured your asset using presets built on a generic test model that will vary from yours.
I would say a combination of adapting the presets to your model by tweaking its base settings combined with some custom work would be the the most efficient way to make something your own, and the optimal but more time consuming way would be to create your own presets using custom source material.
One of the main things I do to kill obvious repetition is layering masking patterns of different scales. I have one or two generate a specific pattern, then one on top removing that detail, scaled to not tile at the same rate. This creates unique artifacts over the entire surface area and breaks up the repetitive details nicely. I also sometimes use several instances of the same material for subtle variation based on position, exposure to elements, manufacturing artifacts and so on. In the end though, pushing an asset those last percentages towards completion should be done by hand if you ask me, and breaking up a few repetitive spots is easily done with 3D mask painting.
Tips and Tricks
I think the most important thing for new users is to realize that the entire Smart Material library was built using the Quixel Suite and that anything I have made, they can make too. I don’t use any special tools the users do not possess. I consider the included library a list of examples of what can be done, a pretty comprehensive list maybe, but examples nonetheless.
Most user-made tutorials often glance over the Basic Materials library, but it’s truly the backbone of the system. The Basic Materials are the building blocks of the Smart Materials and they sometimes do the job just fine on their own without complicating things. If you want to create custom materials that are truly your own, this is the place to customize. You can make a custom base material from any image gathered from any source. This is also how a user could make things like materials with hand painted bases for the Suite by simply importing hand painted maps into the system and making a custom stylized base to build upon.
The library currently lacks stylized base material examples, something we have talked about adding in the future. Building your own is surprisingly simple, and DDO has been used extensively in the AAA industry for stylized pipelines.
The Times They Are A Changin’
The major part of this change is happening right now. I don’t think there is a better way to make materials then to use scan based image data combined with procedural systems and the hands of talented people. I have no reason to believe the material artist will go away, the production will just move more towards predefined libraries of high quality source material. I constantly find things I need that we either don’t have in the library yet or that simply doesn’t exist, and if I do, I make them. The base library of the Quixel Suite is a good example of that as a few of the previously missing base materials were simply made with NDO and Photoshop.
Expect me to nerd up the standard by a fair amount along with the release of Megascans with some very advanced and intricate materials.