Sharlene Lin prepared a breakdown of her Japanese Stone Wall made in ZBrush and Substance Designer sharing the graphs and other details.
My name is Sharlene Lin. I grew up in China where I studied traditional and graphic art at one of the top art schools in China. Later I went to college to study Computer Art and graduated from the School of Visual Art in NYC.
In New York City I was able to work with many amazing artists at commercial studios but later on, I moved to California to chase my dream to do movies.
I began my career in visual effects and film production around 2010. I was able to contribute to several movies including “Snow White and The Huntsman” and its sequel, “The Huntsman: Winter’s War”, “The Avengers”, “Jack Reacher”, “Looper”, “Twilight Saga: Breaking Dawn”, and others.
I learned how to build precise models that match real life measurement and details. Modeling for movies that require destruction is also really interesting because you need to make sure all the models are built almost like real life. Models were made as to not penetrate into each other, and this is used for destruction simulation effects.
At The Mill, I worked on many commercials for brands including “Hay Day”, “Game of War”, “Halo”, “Honda”, and “Kia’s 2017 Super Bowl spot, Hero’s Journey”. I also worked on “HELP”, the VR short film for Google Spotlight Stories. “Xbox One insects” and “It’s a Tide(Super Bowl 2018)” are of my latest works.
Currently, I moved to Redmond Washington area with my husband, and now I want to join the game industry so I am learning workflows for game art.
Importance of Reference & Details
Before I start to make textures, I gather as much reference as possible. Reference must be from the right location, for example, a wall from different places will have different iconic features. Knowing location and construction styles is important to convey a realistic sense.
After gathering all the reference images I will pick a couple of images that I think are the best for the project. Normally, I would not follow just one reference, it could be a mix of a few features I really love.
I also pay attention to the details. In the case of Japanese Stone Wall, l added dust, water dripping, and little moss to make the material more convincing because the wall reference is from a Japanese castle and I know that the weather in that area is rainy.
Stone Shapes & Pattern
Here are some references that I gathered:
The shapes I followed the most were in between A and C in my main reference.
I started with a tileable plane in ZBrush, then used cubes to lay out all the shapes close to the reference.
I divided the cube to have enough geometry to start sculpting and if I need to go into more steps I would divide more. It is important to get the main shape first and then move into details later. I used freehand sculpting in the start for general bumpiness with “Clay” and “ClayBuildup” brushes, plus used “TrimDynamic” brush to sharpen some area. When it came to detail I used “Dam_Standard” brush to make cracks and dents. I also used “Surface LightBox NoiseMaker” for the rougher micro detail.
Here is an example of the “NoiseMaker”:
The challenge here is to avoid the main stone pattern to look too repetitive when it tiles. I made sure all the stone shapes and details were different. Furthermore, the tile edge required some attention to make sure it looked and transitioned well when tiling. In the end, I mirrored the stone from the top to the bottom and from the left to the right, then exported them for baking maps in Substance Designer.
Export to Substance Designer
After the final sculpting, I exported the high poly and the tile plane (low poly) to Substance Designer. Designer baked my ZBrush sculpture well and showed a lot of depth inside my height. As a note, make sure the sub-sampling setting in baking properties is up to 8×8 Anti-Aliasing so it captures defined details. The trick is just testing the sculpt bakes in Designer and making sure the forms are set in a way as to not have areas of stretching. I added extra detail onto the sculpt inside Designer with noise nodes and also made a grout for the destroyed version of the wall.
I created the main base colors in Substance Designer. Besides height map and normal map, I also baked a color ID map. I used “Grayscale Conversion” converted the ID map to grayscale, then used “Gradient Map” color picker to pick the color from reference. I will do the same step a couple of time and use “Blend” nodes to mix the colors until the base color looks the way I want.
I connected and used “Gradient Map” nodes on the height, curvature, cavity, and other mask passes to blend the grain and detail together. I also applied “Uniform Color” nodes to blend in using “noise” and “grunge maps” to emphasize the rock surface details. Some of the “noise” was warped in order to make it fit the main shape better.
For the white spots on the rocks, I used “Normal map” connected to the “Light” node which gives you the ability to tweak the direction light based on the “Normal Map”. Afterward, I used general masks to blend with different noise to get the dirty look.
Additionally, I used the same method with adding a Grunge Map to “Directional Warp” node to create the water dripping effect.
Next is Roughness maps. I used grayscale “Grayscale Conversion” converted the albedo to grayscale map just to get a general quickbase. Than I blended it with dirt and water dripping maps together to make sure the water dripping map would look like water.
Further Enhancement with Nodes
I used the height map I baked, attached it to “Auto Levels” node to get the full range and then added “Highpass_Grayscale” to equalize the height levels. I used a “Histogram_Scan” for clipping in between the stones and a “Bevel” node to expand the edges. Then I used the “HQ blur” to smooth the edges and made sure it was inverted. Using a “Slope Blur” Node with a noise helped create the effect like it is starting to chip. The rest was blended with noise and cracks with a “Directional warp” node to add a sense of gravity. Once it was all done it was blended with “Max Lighten”.
With Marmoset Toolbag, I brought in a basic wall plane for my scene. I wanted to get the feeling as if you were looking at an actual japanese wall, so I had an idea of adding different light setups to show the texture. One of my favorite ones was with the streetlight because it gives a little bit of a story even if the scene is really simple. The material setup was pretty basic, but the lighting really helped to present it well. As for displacement, it comes from the height map: I tweaked it and made sure it was well balanced with the normal map intensity and roughness passes.
Simple River Stones by Stan Brown is a procedural material for your environments fully made in Substance Designer. The package includes a fully commented and organized graph for study and customization.