Johnny Fehr returns to tell us about the latest project – The Real Story Behind R2 D2, explained how the idea behind this project was born, and shared some interesting texturing techniques.
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Hey! It is a pleasure and honor for me to do an interview for you again. For those who don't know me yet my name is Johnny Fehr and I'm from Switzerland. I work as a CG Generalist at Cloudscape in Zurich and freelance for Quixel.
Originally I learned the job of Industrial Painter. At the same time, I started getting interested in 3D and photography and started to study the world of 3D at the "Youtube University" as I call it for fun.
The Real Story Behind R2 D2
The reason this project was created is that I wanted to improve my texturing skills. Luckily I got the R2 D2 model from Natale Palazzo who is a really good modeler. I only had to UV unwrap the mesh and then the fun part could begin.
First, I blocked out the materials and the different colors, using references from the film. As you may have noticed, R2 D2 doesn't really have the same colors he does in the movies. I have only taken the color distribution, that is, which parts have the same color from the film.
I decided to make a slightly different version of him because there are already so many normal R2 D2s. Since I was playing Cyberpunk 2077 at the time, the inspiration was quickly found. I decided to make a cyberpunk R2 D2.
First, I baked all the support Maps like Ambient Occlusion and Curvature in Substance Painter. I also did the World Normals to make a dust layer on top of the model.
In Mari, I used the old-school workflow where you first paint the Albedo Map and later extract the other maps from it. I was not familiar with the material workflow when I started the project, but this has changed in the process.
When texturing something it is important to understand how the surface would have been done in the real world. In this case, we are talking about a hard surface robot. That is, at the bottom there is metal, on top of that is an adhesive primer, and then comes the paint. My time being a painter really paid off here. So, what you should do is start with the lowest material and then work your way up, layer by layer.
The most fun and at the same time the most time-consuming part of hard surfaces are the color edge breakups that are made with the help of masks. I started procedurally and took the curvature bakes as a basis and combined them with fractal noise and tileable textures to create a smart mask.
I also have a tutorial for this on YouTube:
But such procedural masks often look very CG. So I used hand-painting to break up the patterns a bit and added some damage here and there. This step is very important because it is the only way to add realism. Reference pictures can help to see at which position wear and damage arise.
After I had finished all the edgeware masks, I set to work on the dirt. I often start with completely red material and then create the mask with the same technique as with the edgeware but simply with the Ambient Occlusion instead of Curvature. Thanks to the red color, I can see very well how the mask looks. After I had the procedural mask ready I loaded a texture and switched the red with the texture. Now I just had to do the hero hand-painting to break up the procedural mask.
Now it was time for decorations. I wanted the R2 to get a used look, so I used the Quixel graffiti tags that I once made for Quixel. So, the poor R2 got a bit of vandalism, which helped to tell the story of the little robot.
Last but not least, I made a dust layer with the help of the World Normal and the Ambient Occlusion Map. The effect is quite subtle but it helps a lot to melt everything together. For this, I used only one color in the lighter brown range. With the mix slider in the Merge node, I adjusted how strong I want this layer to be visible.
After I finished the Albedo Map, I created the Metalness, Roughness, and Bump Maps with the help of the masks. It was important to desaturate the respective stream first and then adjust it with a grade or Levels node so that it fits and was not too strong or too weak.
When I had all the Maps ready it was time for the first test render. I exported all textures and loaded them into an Arnold shader in Maya. Here I also used the ACES workflow because it helps a lot in terms of realism. For the light, I just used an HDRI.
I was a bit surprised that everything fit so well. I only had to boost the Bump Map a bit but all the rest looked very good. Usually, there is another iteration in Mari to make a few small fixes. But here everything fit perfectly so I was very happy.
I posted the first test rendering on the highly recommended Discord server CG Lounge to get feedback. Feedback is very important because people look at your work with a fresh pair of eyes, so they are able to notice some mistakes that you might have missed. We came up with the idea to make one of his legs in a different color to add more to the story.
So I went back to the Mari once again. Since I had all the edge breakups and details, the color was quickly adjusted and some minor hero details were painted to visually explain why this leg could be a spare part.
By then, all I had to do is find good render settings and set the AOVs as well as the resolution high and render. I use Photoshop to do the compositing because it's the fastest and most flexible tool for images for me.
I always start with the same things. Some sharpening here and there, some brightening to guide the viewer a bit. Minor retouching and fix it in post-processing. After that, I start adding the effects. A little brighten a little more contrast with the gradation curve. I also like to zap through a few LUTs to narrow the grading a bit in a certain direction or mood. Then I color the depths, middles, and highlights. Darken in places with a large round black brush and from the main light direction a soft glow with a large white brush. Finally, a little bit of chromatic aberration and grain for more realism.
This was my whole workflow for this project. I hope it has brought you some exciting insights
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