Function: buildLayeredPrismGeometry()

function buildLayeredPrismGeometry(
   tile, 
   coreRadius, 
   solHeight, 
   shellThickness): LayeredPrismGeometry;

Builds the single-band hex prism for a tile — spans [coreRadius, coreRadius + solHeight], capped at the sol surface.

solHeight is clamped to [0, shellThickness]. Callers pass the clamped value — this function is the authority on the geometry layout, not on the game rules that drive solHeight.

The returned geometry is non-indexed (one triangle per 3 vertices), so mergeGeometries can batch it across tiles without index shifts.

Parameters

Parameter	Type	Description
tile	Tile	Hex/pentagon tile on the hexasphere.
coreRadius	number	World-space radius of the inner core sphere.
solHeight	number	World-space height of the sol band ([0, shellThickness]).
shellThickness	number	World-space radial span of the sol band, i.e. solOuterRadius - coreRadius.

Returns

LayeredPrismGeometry