Industry spawn rates

[FulliAutomatix]

So I'll go straight to the point: I'm developing a small chain of industries for the RUKTS extension set, only 2 new ones, and I cannot for the life of me figure out how the spawn rates work.
There's the 2 variables "prob_in_game" and "prob_random", both with maximum possible values of 255 iirc, but I don't understand how this works. Does higher mean more spawn? Does lower mean more spawn? In the 9 months I've had this lying around I've always had the same problem that the industries will just flood the map, with over 1000 nuclear sites one a 2k by 4k map, with every other industry barely having over 100 of each example (using FIRS Extreme economy).

I have also disabled industries closing for these two and I can't remember why, and they only spawn near water (see the repo for that code). I have also changed the behaviour of the power station, and also giving it new graphics, but it behaves normally.

The full repo can be found here

Here be the two items in question:

[+] Spoiler

Code: Select all

item(FEAT_INDUSTRIES, uran_mine){
	property {
		substitute            : 0x00 ;
		layouts               : [tilelayout_uran_mine] ;
		life_type             : IND_LIFE_TYPE_EXTRACTIVE ;
		fund_cost_multiplier  : 37 ;
		prod_cargo_types      : [cargotype("URAN")] ;
		accept_cargo_types    : [] ;
		conflicting_ind_types : [0x01] ;
		prod_multiplier       : [16] ;
		prob_random           : 7 ;
		prob_in_game          : 30 ;
		map_colour            : 255 ;
		spec_flags            : bitmask(IND_FLAG_BUILT_ONLY_AFTER_1960) ;
		new_ind_msg           : TTD_STR_NEWS_INDUSTRY_CONSTRUCTION ;
		name                  : string(STR_URANMINE_NAME) ;
		nearby_station_name   : string(STR_URANMINE_STATION_NAME) ;
	}
	graphics {
		produce_256_ticks			: uran_mine_produce_monthly ;
		location_check				: uran_mine_water_check ;
		monthly_prod_change			: sw_uran_monthly_change_check ;
		construction_probability	: sw_nuclear_build_date_check ;
		//random_prod_change    : nucrep_random_prod_change_switch ;
	}
}

item(FEAT_INDUSTRIES, nuclear_reprocessing_site){
	property {
		substitute            : 0x01 ;
		layouts               : [tilelayout_nucrep_site_a, tilelayout_nucrep_site_b] ;
		life_type             : IND_LIFE_TYPE_BLACK_HOLE ;
		fund_cost_multiplier  : 255 ;
		prod_cargo_types      : [] ;
		accept_cargo_types    : [cargotype("NWST")] ;
		conflicting_ind_types : [industry_type(IND_TYPE_OLD, 0x01), industry_type(IND_TYPE_NEW, 0), industry_type(IND_TYPE_NEW, 1)] ;
		prob_map_gen           : 10 ;
		prob_in_game          : 50 ;
		map_colour            : 208 ;
		//spec_flags            : bitmask(IND_FLAG_BUILT_ONLY_AFTER_1960) ;
		new_ind_msg           : TTD_STR_NEWS_INDUSTRY_CONSTRUCTION ;
		name                  : string(STR_NUCPROC_NAME) ;
		nearby_station_name   : string(STR_NUCPROC_STATION_NAME) ;
	}
	graphics {
		//produce_cargo_arrival		: nucrep_cargo_arrive_produce ;
		produce_256_ticks			: nucrep_produce_monthly ;
		location_check				: sw_nucrep_water_check ;
		//monthly_prod_change			: sw_nucrep_monthly_prod_change_check ;
		//random_prod_change			: sw_nucrep_random_prod_change_switch ;
		construction_probability	: sw_nuclear_build_date_check ;
		//colour                : sw_nucrep_colour_check ;
	}
}

Any help would be lovely, I can't get enough info out of the NML documentation.

[Pyoro]

As I understand, those values basically "don't mean anything" except whatever they are relative to other industries. ie if you have industry A with a prob of 1 and industry B with a prob of 2 it means you get twice as many of industry B (the total being controlled by the game settings and map size). But you also could have given them the values of 100 and 200 or 17 and 34 or whatever for the same result.

FIRS values are fairly low; so 30 and 50 are, yeah, about twice as high as anything else FIRS spawns. You can compare here:
https://dev.openttdcoop.org/projects/firs/files

Mill for example has 10/10. Lots of others have something like 5/3 or whatever.

[PikkaBird]

They're relative indeed, and the spawn rates may also be affected by location limits (eg needing a coastline, or needing to be a certain distance from other industries).

[wallyweb]

Any help would be lovely, I can't get enough info out of the NML documentation.

Sometimes the original reference is handy. The GRF Specs might help you to fill in the blanks.

[FulliAutomatix]

Thanks for the help! I managed to fix all the issues I was having