Stone Access

Access the current gemstone's geometric properties and raw mesh data for custom calculations, validation, and advanced scripting.

The `stone()` Function

Call stone() anywhere in your script to get a snapshot of the current gemstone state. This returns an object containing computed metrics, raw vertices, and face data.

name = "Stone Access Demo"
gear = 96

// Cut some pavilion facets
P1 0 @ 41.8 : 0.18 x8

// Get current stone state
s = stone()

// Check metrics
print("Stone Name:", s.name)
print("Facets:", s.facetCount)
print("Table %:", s.tablePercentage)
print("Depth %:", s.depthPercentage)

-- lua script
name("Stone Access Demo")
gear(96)

-- Cut some pavilion facets
TierAD("P1", 0, 41.8, 0.18, "x8")

-- Get current stone state
local s = stone()

-- Check metrics
print("Stone Name:", s.name)
print("Facets:", s.facetCount)
print("Table %:", s.tablePercentage)
print("Depth %:", s.depthPercentage)

Available Properties

Computed Metrics

Property	Type	Description
`facetCount`	Number	Total number of facets on the stone
`tablePercentage`	Number	Table width as percentage of stone width
`depthPercentage`	Number	Total depth as percentage of width
`crownHeight`	Number	Crown height as percentage of total depth
`pavilionDepth`	Number	Pavilion depth as percentage of total depth
`girdleThickness`	Number	Average girdle thickness as percentage of width
`compactness`	Number	Volume filling of footprint envelope
`lengthWidthRatio`	Number	Ratio of longest to shortest horizontal dimension
`isGirdleEven`	Boolean	Whether all girdle facets are uniform
`isGirdleOK`	Boolean	Checks overall integrity, corners, and angles
`vertexCount`	Number	Number of vertices in the polyhedron
`name`	String	Name of the gemstone design
`refractiveIndex`	Number	Material refractive index

Raw Geometry

Property	Type	Description
`vertices`	Array of Points	All vertex positions as `Point(x, y, z)`
`faces`	Array of Arrays	Each face as an array of vertex indices

Examples

Iterating Over Vertices

name = "Vertex Analysis"
gear = 96

P1 0 @ 41.8 : 0.18 x8

s = stone()

// Find the lowest point on the stone
minZ = 1000
s.vertices.forEach((v) => {
  minZ = v.z < minZ ? v.z : minZ
})

print("Lowest Z:", minZ)

-- lua script
name("Vertex Analysis")
gear(96)

TierAD("P1", 0, 41.8, 0.18, "x8")

local s = stone()

-- Find the lowest point on the stone
local minZ = 1000
for _, v in ipairs(s.vertices) do
  minZ = v.z < minZ and v.z or minZ
end

print("Lowest Z:", minZ)

Computing Face Normals

name = "Face Normal Computation"
gear = 96
size = 1.0

P1 0 @ 41.8 : 0.18 x8
G1 0 @ 90 : size x8

s = stone()

// Compute normal for first face
face = s.faces[0]
v0 = s.vertices[face[0]]
v1 = s.vertices[face[1]]
v2 = s.vertices[face[2]]

// Cross product of two edges
edge1 = v1 - v0
edge2 = v2 - v0
normal = edge1.cross(edge2).normalize()

print("Face 0 normal:", normal)

-- lua script
name("Face Normal Computation")
gear(96)

TierAD("P1", 0, 41.8, 0.18, "x8")
TierAD("G1", 0, 90, 1.0, "x8")

local s = stone()

-- Compute normal for first face
local face = s.faces[1]
local v0 = s.vertices[face[1]]
local v1 = s.vertices[face[2]]
local v2 = s.vertices[face[3]]

-- Cross product of two edges
local edge1 = v1:sub(v0)
local edge2 = v2:sub(v0)
local normal = edge1:cross(edge2):normalize()

print("Face 0 normal:", normal)

Checking Metrics for Validation

name = "Metric Validation"
gear = 96

P1 0 @ 41.8 : 0.18 x8

s = stone()

// Log a warning if depth is too shallow
msg = s.depthPercentage < 50 ? "Warning: shallow depth" : "Depth OK"
print(msg, s.depthPercentage, "%")

-- lua script
name("Metric Validation")
gear(96)

TierAD("P1", 0, 41.8, 0.18, "x8")

local s = stone()

-- Log a warning if depth is too shallow
local msg = s.depthPercentage < 50 and "Warning: shallow depth" or "Depth OK"
print(msg, s.depthPercentage, "%")

Computing Volume Bounds

name = "Bounding Box"
gear = 96

P1 0 @ 41.8 : 0.18 x8

s = stone()

minX = 1000; maxX = -1000
minY = 1000; maxY = -1000
minZ = 1000; maxZ = -1000

s.vertices.forEach((v) => {
  minX = v.x < minX ? v.x : minX
  maxX = v.x > maxX ? v.x : maxX
  minY = v.y < minY ? v.y : minY
  maxY = v.y > maxY ? v.y : maxY
  minZ = v.z < minZ ? v.z : minZ
  maxZ = v.z > maxZ ? v.z : maxZ
})

print("Bounds X:", minX, "to", maxX)
print("Bounds Y:", minY, "to", maxY)
print("Bounds Z:", minZ, "to", maxZ)

-- lua script
name("Bounding Box")
gear(96)

TierAD("P1", 0, 41.8, 0.18, "x8")

local s = stone()

local minX = 1000; local maxX = -1000
local minY = 1000; local maxY = -1000
local minZ = 1000; local maxZ = -1000

for _, v in ipairs(s.vertices) do
  minX = v.x < minX and v.x or minX
  maxX = v.x > maxX and v.x or maxX
  minY = v.y < minY and v.y or minY
  maxY = v.y > maxY and v.y or maxY
  minZ = v.z < minZ and v.z or minZ
  maxZ = v.z > maxZ and v.z or maxZ
end

print("Bounds X:", minX, "to", maxX)
print("Bounds Y:", minY, "to", maxY)
print("Bounds Z:", minZ, "to", maxZ)

Notes

The stone() function returns a snapshot at the moment it is called. If you cut more facets, call stone() again to get updated data.
The vertices and faces arrays are read-only copies—modifying them will not affect the actual stone geometry.
Face indices are zero-based and reference positions in the vertices array.
All coordinates are in the standard ProFacet coordinate system where +Z is the crown (up) direction.

Keyboard shortcuts

ProFacet Handbook