Mapping¶

The mapping node group of materials unlocks several UV mapping options. The node group can be found in the Shader Editor window.

mapping node group

The first slider UV/Object Mapping switches between two distinct ways of mapping materials to the object. If its value is 0, UV mapping is applied and if value is 1, object mapping takes place.

UV Mapping¶

uv mapping example

Classic UV mapping enables more freedom and customization but it is harder to do right and usually needs to be repaired when mesh is edited. UV mapping is very useful on geometry where you would like to have different scales or rotations on various parts.

Anisotropic materials can be UV mapped quite easily in most circumstances. Some examples of anisotropic materials could be wood grain, brushed steel or some composite materials.

How to create uv map

Simply select all in edit mode with A, press U and choose Smart UV project. Depending on geometry and edge seams, this works in about 90% of cases.

Object Mapping¶

object mapping example

Object mapping is generated automatically and it does not require UVs but it is better to have some UVs for normal map tangents to work. It does not need to be manually set up or corrected when geometry changes.

Unlike UV mapping it is best with isotropic materials like concrete, aluminium, water, glass or stone. When it comes to anisotropic materials it can work well if the direction only goes horizontally or vertically.

Tip

You can rotate the mapping as you would like to get most out of generated mapping without need for UVs.

Random per Object Mapping¶

Mapping is offset randomly per object to prevent repeating on objects in a row.

Adjust to Object Scale¶

Mapping scales according to object scale to avoid shrink and stretch.

Adjust to Object Rotation¶

Mapping rotates to keep water level, it works best for single axis rotations.

Mapping Offset/Scale/Rotation¶

Adjusts offset, scale or rotation of the mapping. It needs to be noted that object mapping rotations leave sharp seams between different projection planes. This is a limitation of box mapping.

Random UV map

To randomize UVs per element of the object, create 2 new UV maps by clicking twice on the + icon. Then double click on the second one and rename it to "Random". Reason to have 2 UV maps is to have normal maps working correctly because of tangents.

In 3D View, press U and use Project from View or Smart UV Project. Smart UV project takes seams into account. Then in UV/Image Editor use UVs → Pack Islands. Lastly in UV/Image Editor change pivot to Individual Origins and scale everything to 0 by pressing S.