Week one: PBR Practice Project

Back from holidays and maybe not as rested as I’d like to be our first project was an enjoyable one; PBR or Physically Based Rendering is a real time rendering exercise that takes into account the real-life properties of a material in order to replicate it as realistically as possible in the game engine.

PBR takes into account not only if the surfaces reflect light but also how they scatter – or don’t scatter the light that hits them, combining metalness maps, roughness maps and Albedo maps with the familiar normal map to give you the basic information for the materials.

Your Albedo map is your new Diffuse; with minimum ambient lighting and as little specular information as possible the Albedo represents the colour information of the object if all outside influences had been stripped away.

The Metalness map is about what it sounds like, anything that’s made of a metal is white on this texture and anything that’s not, is black. Though grey is sometimes used for transitions between the two or for things like dirty metal, it’s really a minimum.

Roughness defines how the material effects the light that’s bouncing off it, the blacker the area of the map the more precise and in focus the reflection will be.

Extras can be added like Subsurface colours but combining them together it makes it possible to create an accurate representation of pretty much any material, provided you know the properties of it.

For this project we were to produce 9 different materials; Wax, Steel, Copper, Rust, PVC Plastic, Car Paint, Leather, Gold and Stone but after I’d completed those I went on to produce some of my own; Brick, Wood, Mirror, A cracked rock with Lava, skin, velvet, fabric and iridescent car paint.

Top Line: Fabric, Iridescent, Lava Rock, Skin, Velvet

Middle Line: Leather, PVC Plastic, Car Paint, Rust, Stone

Bottom line: Wax, Gold, Steel, Copper, Mirror, Brick, Wood

Some were more successful than others but I found this type of texturing a joy to work with. With a little work it was possible to create gorgeous textures quickly and simply. The real-time rendering of things like reflections means that Cube maps are not needed.

Overall this project was a success though there’s a couple of materials that I’m going to be re-doing in my spare time (Velvet and Iridescent in particular were head scratchers) It was a great way to start off the year learning something new and seeing some nice results pretty much immediately. Can’t wait to see how I can use it in later projects!

Some of the materials up close and their material’s windows:

 

Gold was supremely simple, but produced such a good result.

Iridecent in particular was a challenge; getting it to look like this was relatively easy it was a matter of replicating the carpaint with an additional coloured map over the top for the coloured shine however getting that texture to react to the movement of the camera is something I wasn’t able to find and something I am still looking for.