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3D Rendering: Challenges and solutions

3D artist Clemens Sonntag on internal and product design using Cinema 4D, U-Render and other tools.

Located in Berlin, a passion for animation films from an early age and endless creativity, this is how Clemens Sonntag describes himself. In this interview he tells us how he added product design to his creative animation work and how he manages to combine different tools and workflows.

Please tell us about your job and your background.

Clemens: I always loved movies so after school, and a couple of internships, I studied digital film and animation. After that, I started freelancing doing VFX and some 3D animation for smaller jobs. The first years were kind of rocky. Finding good clients is hard when you don’t have so much to show. But I kept going and after many nights sitting at home watching tutorials, creating content and meeting the right people, I managed to make a living. Now I’m doing 3D for advertisements and I love it. But creating things that aren’t ‘real’ still feels like magic to me.

Which renderer do you usually work with?

Clemens: Mostly Octane, sometimes Redshift and U-Render when speed is a higher priority than realism.

Please summarize three points of frustration you faced.

Clemens: When you have finally finished your animation, and you want to render it but for some reason the renderer keeps crashing. This is the worst. But having to stop working on the animation in order to have sufficient time to render, is also something I would like to avoid or at least to reduce.

How did your workflow get stuck because of them?

Clemens: Random crashes, staying up all night watching the frames arrive because you don’t trust your render to be finished in the morning for the delivery. Or having to find solutions in order to optimize the scene because the VRAM is full or certain parts of the image are killing the render time. Though this might not always have something to do with the render engine.

What was the big ‘A-ha!’ moment when you realized you needed to try something new?

Clemens: I was working on a project for an industrial valves producer. The animation was kind of slow, so there wasn’t too much happening, but because of that almost every change affected all frames and there were thousands of them. This was the moment when I started to look for an alternative renderer. I researched for a real-time renderer solution on YouTube and I found U-Render. The final result was very good and the client was satisfied with it. 

What was the top reason you selected U-Render?

Clemens: Render speed. Eevee and Unreal Engine would have been a very good choice as well, but I really wanted to stay in Cinema 4D. Learning a completely new software or exporting the whole scene every time I want to render, was not an option for me. U-Render is fully integrated in my 3D application, easy to learn and it works in real-time: I could not ask for more.

Was it hard to switch between render engines in your project?

Clemens: When you are using the native C4D shaders, which every renderer I know understands, it’s rather easy. But some renderers need different types of light and displacement never works the same way and so do volumetrics. So in the end you are better off when you decide which renderer is best for the job and you stick with it.

What kind of hardware do you use during the production?

Clemens: I use an Intel Core i9 9900K, RTX 2080 ti and 64GB DDR4 RAM. When I need more render power a colleague with 2x RTX 2080 ti and 1x RTX 3080 is helping me out. I’m planning to build a new PC when the new Nvidia RTX 4000 series is coming out.

How has U-Render helped you to overcome the challenges you had before?

Clemens: For my internal design project, called Curtains, I really needed volumetrics but I also wanted the beautiful lighting Octane provides. Rendering Octane’s volumetrics still is a nightmare in my opinion (even though they improved over the years), so I came up with an alternative solution. I changed all the materials to black and used the volumetrics from U-Render. Rendered it all in 4K in a couple of minutes and added it as a layer in post. For finer details I added some noise to the fog layer. This really saved me hours of rendering and I don’t really see a visual disadvantage if you crank up the settings.


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Curtains made by Clemens Sonntag

How did your workflow change once you used U-Render?

Clemens: I’m not afraid of volumetrics any more! Being able to render volumetrics that fast and the way U-Render handles refractions really impressed me as well. Also Subsurface Scattering looks pretty good. I needed a renderer for Cinema 4D that is really fast and for that U-Render is great. Even though it’s not really real-time when I crank up the settings and set it to 4K but that’s fine. I can wait seconds instead of hours and days like with other renders.


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