What is UDIM?

UDIM is a method of using a number to represent UV tile offset in a 3D Model's texture coordinates. The UDIM ID numbers range in ShaderMap from 1001 to 9999. See below how a UDIM texture is laid out. Each tile represents a complete range of texture coordinates UV (0,0) to (1,1) plus UV offset integers for the specific tiles:



The value U Max represents the maximum number of tiles horizontally. In ShaderMap the maximum U is set to 10, this is a common UDIM U max value, but can be changed in the Options and Settings / Maps section.

How is UDIM used in ShaderMap?

Any Map that ships with ShaderMap and uses a 3D Model as an input supports UDIM tiling. Each of these maps has a property to enable UDIM as well as a numberbox for defining the UDIM ID.

It is common for maps rendered to fit in a UDIM texture to have a postfix which defines its UDIM ID or the UV offset values. When a map has UDIM enabled it will automatically assign the postfix to the output filename of the map. Please note that the output filename must be set for this to happen. The postfix is optional and can take the form of No Postfix, [FILENAME] _ [UDIM ID] . [EXT], or [FILENAME] _ [U OFFSET] _ [V OFFSET] . [EXT]. The format is selected in the Options and Settings / Maps section.