r.grow.distance Generates a raster layer of distance to features in input layer. Raster (r.*) QgsProcessingParameterRasterLayer|input|Input input raster layer|None|False QgsProcessingParameterEnum|metric|Metric|euclidean;squared;maximum;manhattan|False|0|True *QgsProcessingParameterBoolean|-m|Output distances in meters instead of map units|False *QgsProcessingParameterBoolean|-|Calculate distance to nearest NULL cell|False QgsProcessingParameterRasterDestination|distance|Distance QgsProcessingParameterRasterDestination|value|Value of nearest cell