Adds a node that create a 'MeshTriangle' from its members

Vertex Instance ID0
Vertex Instance ID Structure

First vertex instance that makes up this triangle. Indices must be ordered counterclockwise. 

Vertex Instance ID1
Vertex Instance ID Structure

Second vertex instance that makes up this triangle. Indices must be ordered counterclockwise. 

Vertex Instance ID2
Vertex Instance ID Structure

Third vertex instance that makes up this triangle. Indices must be ordered counterclockwise. 

Mesh Triangle
Mesh Triangle Structure
