An interview with Staszek Marek, lead lighting and rendering artist from Platige on the Witcher 3 teaser
Can you tell us a little bit about yourself and your role at Platige?
I have been working for Platige for around three years. I was lead lighting and rendering artist on the Witcher 3 teaser.
Can you give me a brief history of Platige?
Platige was founded 16 years ago as a postproduction studio. Over the years it evolved to a creative studio using animation for various projects including game cinematics, content for museums, exhibitions, concerts, commercials and vfx for features.
What was the size of the team that worked on the Witcher 3 cinematic?
If you count credits you will see a team of 50 people. The core team for the project included about 15 people. Rendering team was 6 of us, but most of the time we worked 2-3 people on rendering and lighting at same time.
Which modelling / animation and texturing packages were used?
We used 3ds max and Zbrush for modeling. Maya was our main tool for animation. It is also the central tool of our pipeline. Textures were made mainly in Mari and a little bit in Photoshop.
Why did you use Arnold for this project?
Some time ago we decided that producing the next generation of cinematics require a set of tools that will cope perfectly with increasing level of realism. The tools we used so far weren’t sufficient enough. Doing the most advanced shots we felt like we reached the borders of stability we could get from 3ds max. Having dozens of characters, displacement, SSS, hair, tones of animated geometry required very stable software. We were amazed by the quality of Arnold renders in projects done in other studios. Once we shifted our pipeline towards Maya, Arnold seemed like the best solution. In Platige we did a few commercials with Arnold and the quality was far better than the competition. The Killing Monsters cinematic was the first big project produced using these tools. I admit it took us a moment to get used to all possibilities given by Arnold, but it was definitely worth the effort. There are a few core advantages Arnold gives in photorealistic rendering such as in the Witcher 3 teaser. I am impressed how Arnold handles heavy meshes and huge amounts of high resolution textures. Thanks to the tx format implementation using hundreds or even thousands of big resolution textures didn’t really influence the comfort of the work and render time. It was very important especially in the fighting sequence.
What is more, the philosophy behind sampling was also very convenient to us. I think that the limited amount of parameters that is available in Arnold compared to other software, surprisingly makes the process faster keeping the same level of control. Fewer variables means also that the room for human error is smaller. I am really glad to see the improvement of Maya and Arnold integration. Some functions need working on, but some of them are already working great. For example the support for Maya IPR. I can see the improvement with every update.
The other great quality is the stability and great performance in hair rendering, subsurface scattering and displacements. We had a couple of characters either in closeups or moving dynamically – the realistic look of hair was very important to us.
What is your usual approach to lighting a scene like this?
The first step is always analyzing of concepts and references. We do it very early in production. It is essential to set good direction together with director and art director. In the same time we do research. We test the lighting of the key elements. It might be clothes, environment, skin. We make a lot of tests, to be sure we have proper values and our setup is steady. Then we take environment render from spherical lens and we combine it with sky from HDRI photo. Nuke is a very good tool for that.
This cinematic has a very unique and natural feel, how did you approach the lighting to get this look?
That’s true, once we knew the film takes place during a foggy day, we knew we were aiming at diffused light. We did a lot of reference photos in similar weather conditions. It’s not difficult in Poland during winter. We tested lights on cloth and skin to have reference for the setup. Setting up the shaders turned out to be a real challenge. The flat light revealed all mistakes and imperfections in shader setups. We experimented with many HDRI and most of the look depended on those tests. The result was quite good so that compositing and grading could focus on giving the film the final touches.
Did you have to write any custom shaders to achieve a particular effect?
For this production we haven’t written any custom shaders. We used mostly aiStandard and aiSkin shaders.
What was your approach to the sub-surface scattering and the skin in Witcher 3?
It was quite straightforward – we used default raytraced aiSkin. Both the quality and level of control were very satisfying. The big advantage was that we could forget about the problems we used to have with skin using other renderers. Now we haven’t got any problems with noise, unexpected color changes different kinds of artifacts in rendering and flickering. It didn’t require exceptional settings for sampling either. The only challenge was to balance light levels between the characters and environment but this is something that require more of our research rather than a change in the software. I think this is still a challenge we need to work on.
Were there any challenges that you had to overcome?
Witcher 3 teaser had its creative and pipeline challenges. Working with Tomek Baginski always brings those creative ones – this time it was the grim reality of the teaser, cloudy weather conditions and realism of the characters. It gave us a possibility to explore new areas for lighting and shaders.
Moving to different tools brought a new set of challenges. It was really refreshing to make this leap into new software, explore its possibilities. Though it is always more time consuming when you do it for such a big project as The Witcher. I think we spent a lot of time on hair simulation. We had not expected it would turn out so complex.
How big is your render farm and how long did it take to complete this project?
Our main render farm has approximately two hundred servers. First tests were done on a dozen licenses, right now about half of our servers have Arnold licenses. We had two months for pre-production and the production took four months.
How long were the render times for complex and simple renders?
The average render time was around an hour and a half. It could vary between 30 minutes and 3 hours depending on complexity of the render. AA sampling parameters were somewhere between 5-6, some shots were working great on 3-4, and some of them, especially motion blur on hair needed up to 8.
What can we expect next from Platige?
I wouldn’t like to spoil the surprise of what is to come. Let’s just say that there should be more interesting films in the future.