Making Realistic Materials

“PBR” stands for Physically Based Rendering. This essentially means that generated materials work to match the physics of the real-life material they are supposed to emulate. Metal, for example, is more shiny and reflective. Paint may have some shine, but won’t be nearly as reflective as metal. And raw wood will be more matte and rough.

With PBR, you can create a library of preset materials to be used in any environment and lighting level. No more tweaking every time you create a new scene. Better yet, PBR is pretty much all procedural in nature. It can leverage technology to make your workflow more efficient.

I have been learning PBR using this tutorial, by Blender Guru. You may know him for his Blender donut, and he seriously is a guru with Blender. All of his tutorials are super educational, going beyond the simple “do it like this” and breaking into the actual science and logic behind why you should “do it like this”. I believe his PBR tutorial is a two-parter, and keep in mind that these particular videos are in the hour-long territory. But it’s worth it if two hours can teach you how to build an entire library of realistic materials.

I am currently 45 minutes into the first tutorial. So far, I have learned how important fresnel is in addition to the relationships between roughness, fresnel and reflectivity. I have also used nodes to build a base, nonmetal material that can easily be edited to match the roughness and reflectivity of various materials. So it becomes a matter of duplicating and editing that material to match paint, stone or anything else. The final portion of the first part provides an example of that.

What I Learned

Everything. Has. Fresnel.

Fresnel has an inverse relationship with roughness.

When in the node editor, highlighting multiple nodes and hitting CRTL + G groups those nodes. Tab cycles through the groups.

Selecting a node and hitting CTRL + M mutes that node.

A sun intensity of 5 seems to be a pretty good value.

Try Blender’s Dynamic Sky addon. It creates a procedural sun and sky, complete with clouds.

To pull a node group (call it PBRGroup for this example) into another Blender file, open the target file and click File > Append. Then, in the dialogue box that appears, click the .blend file containing the node group (PBRGroup), click the “NodeTree” folder and double-click the name of the group you want to pull in (PBRGroup). Now, in the shader editor, you can add the node group by hitting SHIFT + A, selecting “Group”, and selecting the name of the node group you just appended (PBRGroup).

If you want some free materials to try this tutorial with, check out ambientCG. The images above contain assets from ambientCG.com, licensed under CC0 1.0 Universal.