Week 1 of University – Introduction to Unreal 4 and Physical Based Rendering

So on my first week back onto university was surprisingly really good. Before I started, I felt anxious and stressed that this is my final year we will be using a new method of texturing materials, inside a new next generation engine, and that I’ve still got to learn how to use z-brush properly.

Little did I know that the PBR method of texturing was actually a lot easier than using the traditional diffuse spec/gloss and normal maps and gave BEAUTIFUL materials for minimal effort.

The diffuse map which originally contained lighting information about the object has now been changed to an ALBEDO Map which is basically the same thing but without any lighting information, so it can just be flat colours depending on what kind of material you are texturing, if it’s a metal or plastic flat colours can work just fine and give a great effect.

So you might be wondering where all of the detail may go into.

Well, Instead of a specular or gloss map, we get something magical called the Roughness map (or Micro detail map if on Marmoset Toolbag).

 This makes your materials on your assets really pop and gives them a lot of definition and realism. Thanks to the PBR shaders of the next gen engine Unreal 4

The Roughness Map is a greyscale map and uses the values in-between black and white to tell the engine how to display light onto the object and determine how smooth or rough a surface is. Black is Smooth and White is Rough, I remember it by thinking white is full and black is empty, so white would be full of roughness and black would be empty of roughness therefore super smooth.

Metalness maps are something new, It’s another greyscale map and depending if its white or black it will make the material you are using more metallic or less metallic. White would mean it is pure metal, while Black would mean it’s a non-metal. The metalness maps are quite important give a huge material definition boost to your material, so any metals you might have on your model should definitely have a metalness map on them. I usually like to plug them into the Alpha to save texture space; if the material isn’t already an alpha.

Specular isn’t entirely replaced though “Specular reflection intensity, or reflectivity is still a very important parameter in PBR systems. You may not have a map to directly set reflectivity (e.g. with a metalness workflow) but it is still required in a PBR system.”

http://www.marmoset.co/toolbag/learn/pbr-practice

Good website to help you understand what PBR is about.

There is a subsurface colour option as well in the material nodes, so it’s very useful for defining materials like skin, wax, ice and any other material that will let light inside the material.

The project I was set was to texture 9 different materials using the PBR Method and I picked it up really well after looking at the examples that were given to us and speaking to my friends who were a bit more knowledgeable about the texturing method.

I created Albedo, Roughness, Metallic and Normal maps in Photoshop and Crazy bump which I then tweaked in Unreal 4 using the material editor with nodes, which was really useful because if I got a material in Photoshop slightly too bright or dark I could change it by combining and changing certain nodes and values in the editor!

Less effort on my end, I don’t have to keep going back to Photoshop and changing it and saving it out again. I really like this engine.

I made a Wood, Ice and Holographic textures for an additional 3 materials, which isn’t much but I was trying to get my head around how the node and material systems work by looking at the example maps provided in Unreal 4.

The wood texture was very simple with a basic albedo, normal and roughness map on them.

I used a tutorial for the ice texture, it wasn’t too specific, it just showed what nodes needed to be used and I had to guess how to create the normal maps myself. Which wasn’t too hard, I just used tillable rock textures which I acquired from cliff photos. There were 3 Normal maps that needed to be used, 1 for the base texture, and 2 for the ice effect which were tiled a lot and multiplied/added with each other to get the sparkly effect you see on ice.

The Subsurface was fairly straight forward, I used the same material nodes for the wax effect also.

There was a weird problem with the ice when I baked the lighting info onto it, it turned really bright blue and looked like an ice slushy, so that’s the reason I pushed it back away from the influence of the light box. 

The hologram was a lot harder and it didn’t turn out how I wanted it to look like in the end. There was a lot of experimenting and I wanted it to look like the hologram you see in Star Wars or Halo but it looked slightly different. Although I think it turned out alright in the end.

I used a very basic mask with a pan and then duplicated them with texture coordinates and a sine wave so I had thick and thin lines panning and flashing with each other. They’re all linked into the emissive map so it was glowing like a proper hologram. I tried to make the opacity lower so you could see a texture underneath, but it didn’t work since the emissive was overpowering the texture, it just looked wrong, so I got rid of it and stuck a constant value in instead.

To conclude, I think I did a good job in portraying most of the materials listed. I struggled at the beginning as one would with a new program and way of texturing but I tried my best and even created something I thought I wouldn’t with the hologram material which I’m really happy about.