Pattern Declaration

Patterns are described as concatenation of field specifiers, that are described in the encoding specification used, don’t care (X) fields when they are required to be masked out and a source field that can be explicitly constructed, or used from a previous src declaration.

pattern water_scatter = MCRT | Material | Elastic | X | Mat("water")
pattern water_scatter = MCRT | Material | Elastic | X | any[Mat(0), Mat("water")]
pattern water_scatter = MCRT | Material | Elastic | X | water_src