As 3D artists, we’re always fighting perfection. By default CG looks perfect, and the real world is full of imperfections. Surfaces get dented, scratched, dusty, and greasy, and it’s our job to add those details.

Let’s start with probably the simplest example: roughness maps. Surfaces with more micro detail—such as sandpaper—are rougher, so the light that hits them bounces off at many different angles and is therefore less reflective than a smooth surface that’s highly polished and reflective.

When we add in a roughness map which is a simple black and white texture, we vary the roughness over the surface and suddenly it looks far more realistic. We can even layer multiple maps like this together with add or multiply nodes in octane.

If we grab the tiles texture from Poliigon.com, it looks a little too clean and perfect. But watch what happens when we add in the roughness map. Here it’s actually a glossy map (which is the inverse of a roughness map), so we need to click the invert button.

Next let’s add in the specular map, which is very similar—but instead of varying the roughness, it varies the specularity, or intensity, of the reflection. Then we'll add the normal map. This causes the surface to act like it’s raised and in general normal maps do the same kind of thing as bump maps but are more accurate because they take into account all the normal directions and angles light can hit the surface.

Note though that these maps aren’t actually raising the surface, just giving the impression of a raised surface. Speaking of bump maps, we can add one of those in too to create some additional scratches on the surface. Bump maps in Octane are usually too strong so we need to mix them down with a multiply node. This is just like the multiply Blend mode in Photoshop or After Effects. If you multiply by a number less than 1, you’re reducing the intensity, so this setup becomes like a mix slider.

Finally, displacement maps actually do move the surface outwards and inwards, so they produce an even more realistic result than normal maps for very raised surfaces, though they are more heavy.

Let’s talk about another overly perfect and computer-generated looking thing that happens in 3D: texture repetitions. Seamless textures tend to be repetitive, but just by creating a duplicate and scaling up, we can have another variation.

Let’s also rotate it 90 degrees for some more randomness. Now if we add in a mix node in Octane, we can blend between the two. And if we use a procedural Octane noise or even another texture, we can use that to vary between the two scales of the original texture.

Now this is looking a lot less repetitive. We can keep doing this too with a third scale, and just keep adding more randomness.

This same thing can be done by layering displacement maps. The more maps we add, the more of an organic looking surface we get.

Finally, let’s take a look at another way to add imperfections by using curvature maps—in Octane it’s called the Dirt node. The edges of objects are typically the surfaces that get the most damaged; often we’ll see something like a metal that’s painted and on the edges the paint is eroding.

To do this, we just create a composite material in Octane, one as a paint and one as a metal. Then we use the dirt node as a mask to show the metal on the edges and the paint as the main surface.

Also we can create more complex mats like this. We took a brick pattern with just the diffuse color, but it was weirdly reflecting the neon lights. Once we added in the roughness map, we solved that problem, and the normal map allowed it to catch the light properly.

Next we created a concrete material and repeated the process. Finally, we created a complex mask to blend between the two using noises and black and white textures, and now it looks like concrete with patches of exposed brick.

Go around your home and take a look at the various surfaces and objects. Notice all the little details, from the scratches on surfaces to the fingerprints left behind on glass. These are the imperfections that you need to bring to your renders to make them more realistic, and—most importantly—a lot more interesting.

Want more?

If you're ready to step into the next level of 3D design, we've got a course that's just right for you. Introducing Lights, Camera, Render, an in-depth advanced Cinema 4D course from David Ariew.

This course will teach you all of the invaluable skills that make up the core of cinematography, helping to propel your career to the next level. You’ll not only learn how to create a high-end professional render every time by mastering cinematic concepts, but you’ll be introduced to valuable assets, tools, and best practices that are critical to creating stunning work that will wow your clients!