Hey guys, welcome to the 3DX artist guide! Each month we discuss the technical aspects of 3DX creation from an artist’s perspective. Each article corresponds to an episode of our 3DX tutorial series, and this month we’re talking about skin and the Iray surface tab! Our characters spend a lot of time naked in front of the camera, after all. So how do we get our ladies to look just right? If you’ve already played around with some character skins, you may have run into trouble.
The curse of assets
In the year 2017, it’s difficult to find skin textures that haven’t been created with a great attention to detail. Take a quick peek at the Daz 3D and Renderosity stores, and you’ll see so many G3F characters that with great levels of detail. They’ve got birthmarks, moles, freckles, tiny blemishes here and there. You see their promo renders and you’re thinking to yourself that with a few facial tweaks, this or that skin would be a great custom look for your character.
So you make the purchase, install the content, and load the iray mats onto your G3F. And she looks horrible! What happened? Her skin is gray, her makeup is overwhelming, she’s way off! Maybe it has to do with the lights you’re using? These skins are made to look great in promos created by artists that have a strong visual signature of their own, after all.
You’re not wrong. Not necessarily. Using these skins in combination with Iray lights from the same asset creator goes a long way to achieving the look you were promised. But then you’re just caught in a loop: you have to use their skins, and their lights, with their surface settings. It feels as though the slightest step out of line invites disaster. What to do? It’s time to learn about how we render skin, or any surface really.
Tailor-made birthday suits
When we talk about how light interacts with a character’s skin in Iray, three factors are most important: translucency, glossiness, and refraction. Translucency determines whether there’s any colour that light might bring out when shined onto a surface. Take a lamp and hold your hand up against it. See the redness of your flesh? That’s what Iray calls translucency.
Then there’s glossiness, which is how wet an object appears. You can always adjust glossiness with a roughness value, which determines whether it’s a really slick oily type wetness or more of a damp moist. Skin is always slightly oily in nature, so finding a good balance here avoids having your characters look like dried-up towels.
Lastly, refraction determines how light breaks onto a surface. Obviously the way light breaks on a human skin is different from how it breaks on rock. Playing with refraction sliders can make your characters take on metallic or glasslike appearances if you’re not careful. In my experience, this slider makes the greatest difference on whether or not your character appears hyper-realistic, or more comic-like.
Look beyond the surface
As beginning artists, there’s an easy trap to fall into. I did. The skin that we see, i.e. the actual image projected onto the wireframe mesh of the model, isn’t what defines your character. But if you’re inexperienced with 3D software you might think it does. This projected image is commonly called a diffuse map. It’s a simple .jpg file designed to provide color information. But a character equipped with just a diffuse map and nothing else is going to look extremely dull.
Many asset creators prefer to augment their diffuse maps’ effects with translucency colors. You might choose to do the opposite. You could turn translucency way down and inject a base colour! Suddenly the entire style of your character turns upside down. You have a lot of freedom to do exactly as you please, so long as you tweak it all down to the right values in the end. Look at it like a puzzle with multiple solutions. This is how artists create their own aesthetic look and feel.
Whether a diffuse map is HD or not really only matters when it comes to close-up shots. A capable artist can take a limited-quality skin texture and enhance it through proper surface manipulation. If you’re trying to strive for realism, keep that in mind. If you’re trying to achieve a more comic-oriented look, keep that in mind too! Don’t go hunting asset stores for that perfectly realistic character, or that perfectly comic-looking character.
Does it help if an artist starts you off on the right path? Sure. And the Daz Store certainly does provide presets designed for specific aesthetics. But ultimately it comes down to how well you understand the surfaces tab in Daz Studio itself.
More next month!
Given that we’re making 3DX, we’re going to have to add genitalia at some point. So next month we’re going to take a look at some of the complications of adding genitalia geografts to our characters, and how we need to use the surfaces tab to even out the resulting inconsistencies. It will also provide us with a good opportunity to take a more indepth look at how surfaces work. See you then!