in ofMesh drawvertices() seems to draw one less vertex than is in the mesh:
void ofApp::setup(){
for(int i = 0; i < 4; i ++){
for(int j = 0; j < 4; j ++){
ofPoint p(i * 100, j * 100, 0);
mesh.addVertex(p);
}
}
}
//--------------------------------------------------------------
void ofApp::draw(){
cam.begin();
ofSetColor(255);
for(int i = 0; i < mesh.getNumVertices(); i++){
ofDrawSphere(mesh.getVertex(i), 3);
}
ofSetColor(0);
mesh.drawVertices();
cam.end();
}