Physically Based Rendering & PBR Textures

A good texturing is one of the basic steps of 3D Visualization. The people who are learning 3D visualization asks in the groups and the forums about the details of the textures or download link of the pbr textures.

Creating quality textures from zero or creating texture maps from the bitmap, after downloading from any free texture site is a very important factor for your 3D project. Sometimes you can’t find exactly what you need and you have to create it yourself.

In this article, you will learn about bitmap to material progress and where you should use them.

What is the PBR Material?

This is a rendering with some physical properties of objects being taken into account. Such an approach provides the appearance of materials as in the real world.

From this logic, we can produce high-quality textures using several methods.

• Bitmap to Material (b2m)
• Photo scanned textures
• Texture painting (Model painting)
• Procedural Texturing

But first, we have to learn about PBR maps and the effect of them on the renders.

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First, download the seamless texture to create maps. On the above, you will see different maps of stone road. Let’s download the diffuse map. We will create Height/Normal/AO/Reflection maps from Diffuse Channel.

Diffuse Map

The diffuse map is the color map of the material. You use the diffuse map or color range on your rendering software to get the final result. Some materials can’t use the diffuse map as a bitmap, they use colors instead of it like metals, glass, mirror. You need to high-resolution images to get a great result.

Specular/Roughness Map

The Specular input should not be connected and left as its default value of 0.5 for most cases. It is valued between 0 and 1 and is used to scale the current amount of specularity on non-metallic surfaces. It has no effect on metals. White areas speculate the light much more than black areas.

Measured Specular Values:

Material	Specular
Glass	0.5
Plastic	0.5
Quartz	0.570
Ice	0.224
Water	0.255
Milk	0.277
Skin	0.35

But we usually don’t use the specular map when we use bitmap on our diffuse channel, prefer Roughness or Glossiness map instead of it

The Roughness input literally controls how rough the Material is. A rough Material will scatter reflected light in more directions than a smooth Material. This can be seen in how blurry or sharp the reflection is or in how broad or tight the specular highlight is. Roughness of 0 (smooth) is a mirror reflection and roughness of 1 (rough) is completely matte or diffuse.

Normal / Bump Map

Bump map is a greyscale image, with white indicating areas that should look higher, and black indicating no level change or lower of height. It uses the light effect to get us this result. Normal and Bump map doesn’t change the real model structure. If you want to show it real you have to use displacement map.

Displacement Map

You can’t model everything. Let’s think, you have to the road like above but you don’t know anything about textures. What will you do? You have to model every stone with damages etc. You need to create a UV map of it and paint it using photoshop or some model paint software. This is very long progress for a simple road. Displacement map our lifesaver.

Displacement or Height map is a greyscale image, with white indicating areas get height, and black indicating no level change or lower of height.It changes the real model structure. You can show real shadows based on your scene lighting and real result.

Now you know a lot of thing about texture maps of PBR Material.

But it is just a start, you have to walk more way if you want to learn it perfectly.

Here some links for you:

PBR Textures