MeshIndexedTriangles

class cee.geo.MeshIndexedTriangles()

This class implements a Mesh for indexed triangles.

Rather than defining each triangle directly as an array of vertices, an array containing x, y and z values for each unique vertex in the part is defined. Then triangles are defined by arrays of indices that refer to elements of this vertex array. This allows triangles to share vertices, thus reducing the number of vertices, and enabling the computation of smooth shade normals.

Note that while the vertices array contains 3 elements per point (x, y and z), the elements in the indices array are interpreted as vertex indices. For example, if vertices contains 3 vertices A, B and C:

vertices = [Ax, Ay, Az, Bx, By, Bz, Cx, Cy, Cz];

Then vertex A is at index 0, vertex B and 1 and vertex C at 2. So the triangle containing these vertices would be defined with

indices = [0, 1, 2];

Constructors

Accessors

Methods

Constructors

constructor

cee.geo.MeshIndexedTriangles.constructor(vertices, indices, optionalVertexData)

Creates an indexed triangle mesh with the given vertices and indices.

Arguments
Return type

cee.geo.MeshIndexedTriangles

Accessors

cee.geo.MeshIndexedTriangles.boundingBox

Returns a copy of the BoundingBox of the mesh

cee.geo.MeshIndexedTriangles.indexArray

A readonly array containing the indices of the mesh

cee.geo.MeshIndexedTriangles.primitiveCount

The number of primitives in the mesh.

cee.geo.MeshIndexedTriangles.primitiveType

The type of primitives that are used in the mesh.

cee.geo.MeshIndexedTriangles.textureCoordinates

A readonly array containing the 2d texture coordinates of the mesh

cee.geo.MeshIndexedTriangles.vertexArray

A readonly array containing the vertices of the mesh

cee.geo.MeshIndexedTriangles.vertexCount

The number of vertices in the mesh.

Methods

getPrimitiveVertices

cee.geo.MeshIndexedTriangles.getPrimitiveVertices(primitiveIndex)

Returns a copy of the vertex indices of a given primitive.

Arguments

  • primitiveIndex (number) –

Return type

[cee.Vec3]

rayIntersect

cee.geo.MeshIndexedTriangles.rayIntersect(ray, hitItem)

Performs picking on the mesh.

Arguments
Return type

boolean

If a primitive was hit, the function returns true and populates the passed hitItem object with information about this primitive. It nothing was hit, returns false.

constructPreserveSharpEdges

cee.geo.MeshIndexedTriangles.constructPreserveSharpEdges(creaseAngleDegrees, vertices, indices, optionalVertexData)

Creates an indexed triangle mesh with the given vertices and indices.

Arguments
Return type

cee.geo.MeshIndexedTriangles

Preserve sharp edges by splitting vertices on edges where the surface normal of the two triangles sharing the edge is more than the given angle (in degrees).