From Solid Graphics Wiki
The TriangleByRef struct specifies a triangle using three integer values. The values specify indexes into a point array which contain actual triangle points coordinates. Therefore using this type is always accompanied by using some kind of point array type, usually the SolidKit3D.PointList class.
Fields
Field name
 Type
 Description

point0
 int
 index of the first triangle point

point1
 int
 index of the second triangle point

point2
 int
 index of the third triangle point

Methods
(indexer)
 Allows to access triangle point indexes by index. Use index 0 to retrieve point0, use index 1 to retrieve point1, use index 2 to retrieve point2.

Area
 Calculates the triangle area.

Center
 Calculates the triangle center point

NormalVector
 Calculates triangle's normal vector

IsSharingPoint
 Determines whether the triangle is sharing a point with anothr triangle

FindPointIndex
 Returns index (0, 1 or 2 ) into it's point field for given point id (point index). If the point id is not used by the triangle then it returns 1.

FindEdge
 Returns index of specified edge, or 1 if edge does is not a part of the triangle. Orientation of the specified edge is ignored during the search.

FindOrientedEdge
 Returns index of specified edge, or 1 if edge does is not a part of the triangle. Orientation of the specified edge is NOT ignored during the search.

FindNonCommonPointIndex
 Returns index (0, 1, or 2) of first noncommon point index of two triangles, or 1 if both triangles use the same points.

AddOffset
 Increments all the point field indexes by given offset.

Reorient
 Reverses the triangle's orientation.

IsSmall
 Returns true if any of the two triangle points are closer to each other than the cMinDistance 'constant'. Otherwise it returns false.

IsValid
 Returns true if the triangle definition is invalid  if any two of it's point indexes reference the same point in the point array. Otherwise it returns false.

IsEqualTo
 Returns true if two triangles have all points common. Otherwise returns false. The function ignores triangles orientation.

LoadFromXML
 Loads the triangle definition from XmlReader.

SaveToXML
 Saves triangle definition into MemoryBuffer as XML.

See Also
SolidKit Library Documentation