Automatic Stylization for Realistic Assets

Victor Kam showed how he uses scanned assets with Kuwahara filter to build his amazing fan project.

Victor Kam showed how he uses scanned assets with Kuwahara filter to build his amazing fan project.

Introduction

Hello, my name is Victor Kam, from Vancouver BC, Canada. I currently work as an artist at Black Bird Interactive. Most recently I worked on the title Homeworld: Deserts of Kharak with a focus on vehicle development. I studied Game Design at a school formerly known as Centre for Digital Imaging and Sound.

Pugsley

Pugsley has been part of my life for 13 years now and I’ve always wanted to do a piece of art that involved her. My main inspiration for the scene was actually a pug buddha statue I found on Etsy. I had actually sculpted one in ZBrush years back and thought it would be great to build a scene around it. As you can tell there is a huge Miyazaki influence throughout the scenes, in particular, Spirited Away. I really wanted this to be a personal piece void of any trends that I can share with my family and friends.

Production process

The main goal of this project was to focus on design and not much on constructing of individual assets. I chose to go this route because time is scarce when working a fulltime gig sandwiched between teaching and of course, life. I picked Megascans for their vast outdoor library and also because I wanted to see how far I could take realistic props and wrap my own style around it.

Using Kuwahara

Basically, the filter does this paint daub effect to your image which is what gives the scene the impression it’s hand-drawn. When researching backgrounds for anime you’ll notice the characters are toon shaded while the backgrounds are fairly detailed and painted.  My final images utilize it much like a depth of field effect so the further the asset is from the camera the more Kuwahara gets applied. Of course, you can apply the effect uniformly across the image.

Vegetation

All the foliage was either Megascans or part Lluis Garcia’s Trees Library for UE4. When it comes to the vines, in particular, they’re a kitbash of a Megascans vine asset that I manually wrapped around the wall in Maya. This just goes to show there are many uses for scan data. Even when texturing the stone pug statues, I used a Megascan rock texture set within Substance Painter and projected it onto the model.

Pug render

The pug is comprised of two components, the toon shading itself and the outline.  The toon shader is a standard shader with a clamped transition between light and shadow. You could extend this by modulating the terminator with a tiling sketch map for more of an inky look.  The outline is done by creating a material that pushes the vertex outwards slightly and unlit to black. I did some research on the shading model in Guilty Gear Xrd, though they use a little more complexity I took the main idea and ran with it.  

To exclude the pug from the Kuwahara you simply create a custom depth pass on the object and mask it out within the post process material.

Can you actually run it all in a game? 

Unfortunately, I would say no to runtime. The Kuwahara effect bogs the frame rate significantly, also I did not bake any lighting.  The lighting is done fully dynamic with a light propagation volume and distance fields. This simply allowed me to create art and design without having to consider the technical bits. I’m not very tech savvy but I hope this will be usable for games in the future especially with the latest GDC stuff the Unreal team showed.

Plans

Initially, Pugtales was storyboarded to about 10 shots.  The ones I never got around to are in between shots like her waking up to the butterfly, trotting through the forest, climbing the stairs and sleeping by the statue. There are no immediate plans to continue the series yet, but I have a ton of ideas of where I can take it.  If I ever get around to learning how to rig and animate you may see Pugtales as an interactive experience in the future.

Victor Kam, Senior Artist at BBI

Interview conducted by Kirill Tokarev

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Comments 1

  • Anonymous user

    I love the atmosphere and lighting in the first picture!

    0

    Anonymous user

    ·5 years ago·

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