Parts

Parts are Roblox parts in Grassy Landscape that spawn throughout the Map. They can be picked up, welded, and cut by players. Parts come in a variety of colors, shapes and sizes. They are one of the core building materials of the game, the other being items.

Spawning

Upon server start, 4,800 parts are spawned around the map. Each part has a random position, size, material, shape and color. For positioning, the map has designated spawn areas for parts and items. An algorithm picks between these areas, giving each one a probability equal to its volume, then calculates a random position and rotation within the area. For shape, each part has a ~60% chance of being a block and a ~40% chance of being a cylinder.

Materials

For material, one is picked according to the probability table below.

Material	Chance	Value
CorrodedMetal	30.6%	0.8
Metal	19.6%	1
SmoothPlastic	19.6%	1
DiamondPlate	13.6%	1.2
Glass	13.6%	1.2
Foil	3.1%	2.5

Below is the code used to calculate that table, which can be run by any injector such as Synapse or Script-Ware. The reason for the (1 / v) ^ 2 formula is that the part spawning script uses that formula when choosing which material to pick. (confirmed by the developer)

local valuebook = require(game.ReplicatedStorage.ValueBook)

local total = 0
for _, v in pairs(valuebook.MaterialValues) do
	total += (1 / v) ^ 2
end

for _, v in pairs(valuebook.Materials) do
	local value = (1 / valuebook.MaterialValues[v])^2
	print(v, tostring((value / total) * 100) .. '%', value)
end

Sizing

For size, the value of the picked material is used as a bias. The bias skews the random distribution such that higher bias values cause lower random numbers to be more common. In practice this means that parts with rarer materials tend to spawn smaller, but all sizes are still possible. Then, the Y and Z values are randomly generated. Each component is calculated as math.random()^bias * 9 + 1, which means a random number from 1 to 10, skewed by the bias. Again, higher biases (such as foil's bias of 2.5) mean that the size will tend towards the 1, while lower biases (such as in the case of corroded metal) tend to skew towards 10.

The maximum value for the X component will be a value N such that Y * Z * N == 125. In order words the maximum volume of the part will be 125 studs squared. The minimum value of the X component is always 0.2. Then a random number is generated between those two values, skewed by the bias once again.

The full function is thusly:

function Part:RandomSize(bias)
	local y = math.random()^bias * 9 + 1
	local z = math.random()^bias * 9 + 1
	local x = math.min(math.random()^bias * (125 / (y * z) - 0.2) + 0.2, 10)
	
	return Vector3.new(x, y, z)
end

Colors

Parts mainly spawn in dull and muted tones, with some greys and whites mixed in. Rather than a list of BrickColors, part colors are generated as Color3 values, so there is an entire spectrum of possible colors. Nonetheless, the spectrum is limited and is only a small fraction of the color space. Here is a graph showing the entire part color spectrum (click on it for a larger version):

On the left is the hue and lightness spectrum, and on the right is the saturation spectrum. The range of saturation values for a color depends on its lightness, which is why there is a separate saturation graph next to the main one. To pick a color from the spectrum, first the game chooses the hue and lightness from the graph on the left, and then it chooses a saturation from the graph on the right. As you can see, brighter colors have a smaller saturation range.

The color generation code is as follows:

local hue = math.random()
local lightness = rand(0.1, 1, 0.75)
local saturation = rand(0.1, 0.5 - (lightness^0.5 * 0.4), 5)

rand(min, max, bias) generates a random number between its two first arguments, biased by the third argument. Notice that lightnesses below 0.1 are impossible to spawn and so are saturations below 0.1, which are both reflected in the graph.

BrickColors found in-game

Name	RGB	Percentage	Rarity
Quill grey	216.85, 223.87, 217.85	7.213750%	One in 13
Mid gray	212.83, 203.80, 202.79	7.055560%	One in 14
Institutional white	255.00, 253.99, 255.00	6.291210%	One in 15
White	242.95, 242.95, 244.96	4.378370%	One in 22
Dark grey	93.36, 114.45, 113.44	4.337610%	One in 23
Black	33.13, 40.16, 41.16	4.192400%	One in 23
Ghost grey	196.77, 191.75, 204.80	3.625740%	One in 27
Sage green	186.73, 198.78, 193.76	3.471220%	One in 28
Dirt brown	73.29, 62.24, 76.30	3.254440%	One in 30
Oyster	189.74, 173.68, 170.67	3.243290%	One in 30
Light grey	194.76, 201.79, 189.74	3.172110%	One in 31
Light stone grey	228.89, 227.89, 232.91	3.111170%	One in 32
Earth green	39.15, 49.19, 42.16	3.052920%	One in 32
Dark taupe	87.34, 70.27, 77.30	2.795100%	One in 35
Cloudy grey	176.69, 169.66, 155.61	2.758360%	One in 36
Smoky grey	88.34, 109.43, 105.41	2.684150%	One in 37
Sand violet	134.52, 105.41, 127.50	2.599380%	One in 38
Sand green	129.51, 152.60, 146.57	2.152280%	One in 46
Hurricane grey	157.62, 135.53, 136.53	2.108570%	One in 47
Pearl	231.90, 234.92, 230.90	1.998100%	One in 50
Slime green	90.35, 112.44, 92.36	1.877930%	One in 53
Grey	163.64, 166.65, 147.58	1.863350%	One in 53
Sand red	141.55, 107.42, 126.49	1.648170%	One in 60
Artichoke	146.57, 159.62, 137.54	1.583570%	One in 63
Silver	152.60, 156.61, 170.67	1.559070%	One in 64
Fossil	144.56, 155.61, 172.67	1.510290%	One in 66
Flint	96.38, 107.42, 87.34	1.384830%	One in 72
Lily white	237.93, 233.91, 237.93	1.249030%	One in 80
Sand yellow	146.57, 147.58, 123.48	1.185030%	One in 84
Earth blue	56.22, 64.25, 69.27	1.158380%	One in 86
Dark stone grey	81.32, 99.39, 97.38	1.139170%	One in 87
Faded green	116.45, 145.57, 121.47	1.084030%	One in 92
Cadet blue	166.65, 177.69, 187.73	0.927810%	One in 107
Pine Cone	109.43, 76.30, 83.33	0.887230%	One in 112
Medium stone grey	178.70, 147.58, 167.65	0.884820%	One in 113
Linen	165.65, 157.62, 141.55	0.873990%	One in 114
Sand blue	126.49, 123.48, 157.62	0.830180%	One in 120
Grime	128.50, 139.54, 108.42	0.775500%	One in 128
Lilac	103.40, 101.40, 137.54	0.475640%	One in 210
Fog	210.82, 214.84, 218.85	0.446790%	One in 223
Earth yellow	79.31, 95.37, 58.23	0.420640%	One in 237
Reddish lilac	141.55, 112.44, 153.60	0.345150%	One in 289
Really black	30.12, 22.09, 31.12	0.331880%	One in 301
Laurel green	168.66, 180.71, 159.62	0.305770%	One in 327
Copper	146.57, 103.40, 107.42	0.294650%	One in 339
Cocoa	53.21, 38.15, 36.14	0.281290%	One in 355
Mulberry	86.34, 47.18, 72.28	0.188020%	One in 531
Moss	123.48, 156.61, 102.40	0.163320%	One in 612
Seashell	224.88, 216.85, 218.85	0.113880%	One in 878
Brown	125.49, 81.32, 94.37	0.099800%	One in 1002
Lavender	143.56, 97.38, 148.58	0.095390%	One in 1048
Bright violet	104.41, 68.27, 109.43	0.072590%	One in 1377
Medium bluish violet	101.40, 118.46, 148.58	0.049780%	One in 2008
Bright reddish lilac	126.49, 85.33, 127.50	0.045700%	One in 2188
Plum	121.47, 73.29, 119.47	0.038530%	One in 2595
Shamrock	94.37, 131.51, 85.33	0.037020%	One in 2701
Tawny	131.51, 88.34, 84.33	0.034180%	One in 2925
Bronze	127.50, 116.45, 77.30	0.030800%	One in 3246
Earth orange	97.38, 68.27, 56.22	0.030510%	One in 3277
Steel blue	85.33, 123.48, 135.53	0.027820%	One in 3594
Bright bluish violet	80.31, 77.30, 123.48	0.027100%	One in 3690
Medium lilac	70.27, 65.25, 108.42	0.026260%	One in 3808
Medium green	161.63, 176.69, 146.57	0.017990%	One in 5558
Storm blue	58.23, 86.34, 101.40	0.017740%	One in 5636
Parsley green	56.22, 95.37, 54.21	0.011880%	One in 8417
Beige	190.74, 191.75, 168.66	0.011060%	One in 9041
Light lilac	178.70, 180.71, 198.78	0.010070%	One in 9930
Bright reddish violet	128.50, 80.31, 117.46	0.008180%	One in 12224
Dark green	51.20, 91.36, 70.27	0.006010%	One in 16638
Light bluish green	184.72, 200.78, 201.79	0.005190%	One in 19267
Turquoise	138.54, 174.68, 174.68	0.004010%	One in 24937
Royal blue	86.34, 107.42, 138.54	0.003270%	One in 30581
Reddish brown	107.42, 62.24, 65.25	0.002430%	One in 41152
Sea green	57.22, 99.39, 64.25	0.001240%	One in 80645
Bright green	75.29, 125.49, 75.29	0.000160%	One in 625000
Burgundy	114.45, 68.27, 67.26	0.000150%	One in 666666

Debug Colors

A debug part, with the BrickColor "Deep orange".

Older versions of Grassy Landscape spawned random BrickColors instead of using a color spectrum. Colors outside the spawnable spectrum are referred to as "debug colors", since they used an unfinished algorithm for debugging purposes (i.e. to get the rest of the game working first). Since there is currently no save system, and all debug colors have been removed from the game, it is no longer possible to encounter a part color outside of the spectrum.

"Rare BrickColors"

When generating colors, the game will refuse to generate any color that happens to be a "rare BrickColor". The list of rare BrickColors is below:

Visual	Name	Reason
	Lig. Yellowich orange	Typo
	Light green (Mint)	Parenthesis
	Phosph. White	Cool name
	Transparent	Transparent
	Tr. Red	Transparent
	Tr. Lg blue	Transparent
	Tr. Blue	Transparent
	Tr. Yellow	Transparent
	Tr. Flu. Reddish orange	Transparent
	Tr. Green	Transparent
	Tr. Flu. Green	Transparent
	Tr. Brown	Transparent
	Tr. Medi. reddish violet	Transparent
	Tr. Bright bluish violet	Transparent
	Tr. Flu. Blue	Transparent
	Tr. Flu. Yellow	Transparent
	Tr. Flu. Red	Transparent
	Red flip/flop	Flip/flop
	Yellow flip/flop	Flip/flop
	Silver flip/flop	Flip/flop
	Sand blue metallic	Metallic
	Sand violet metallic	Metallic
	Sand yellow metallic	Metallic
	Dark grey metallic	Metallic
	Black metallic	Metallic
	Light grey metallic	Metallic
	Gun metallic	Metallic
	Lemon metalic	Bkerr's favorite color

If the algorithm generates a color that is "rare", it will simply re-roll until it lands on one that isn't. Most likely, if someone has a part with one of these colors, it was obtained from an event or someone with the debug GUI.