The plugin implements a custom material editor, which is very similar in operation to Maxwell's MXED standalone material editor:
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The remaining parameters control how the texture is scaled and translated in texture-space. Tile X & Y can be enabled or disabled using the appropriate checkboxes, and their values are set using the numeric input box. When Real Scale is not enabled (Units box set to Relative), the meaning of Tile X & Y is roughly, ‘squeeze this many copies of the texture into the given space’. When Real Scale is enabled (Units box set to Meters), the meaning becomes, ‘make each tile x-number of meters wide’.
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