The aim of this simple tutorial is to explain how to render texture maps that have been exported from Mari using the correct displacement workflow with Arnold. This example uses a creature model and displacement maps (kindly provided by Alex Huguet).
UDIM values are a way of representing the integer coordinates of a texture, from the coordinates of its bottom-left corner in UV space. This way, multiple textures can be used to cover a model, rather than a single, much larger, texture.
This is the convention used by Mari when exporting its UV texture space. It starts at 1001 (0,0) and continues in U for another 10 offsets. It then progresses onto the next row of V, meaning for every 10 in U it moves 1 in V.
The UV offset grid below better shows this relationship (this example only shows a range of five as the creature model uses five displacement maps):
You can see in the UV Texture Editor, that the UV's have been laid out in UV space as 1001 (0,0) to 1005 (5,0) and that the displacement texture files have been named accordingly: