def create_hexagon(radius):
""" Creates a hexagon shape that is centered at (0,0,0) with the corners having a distance of radius to the center and
the normals pointing in direction (0,-1,0).
Returns the tuple (PandaNode, GeomVertexData). """
format = GeomVertexFormat.getV3n3c4t2()
vdata=GeomVertexData('hexagon', format, Geom.UHStatic)
vertex=GeomVertexWriter(vdata, 'vertex')
normal=GeomVertexWriter(vdata, 'normal')
# create the vertices
vertex.addData3f(0,0,0)
normal.addData3f(0,-1,0)
# add the other vertices
for phi in range(0,360,60):
# right-hand-rule (with middle finger pointing upwards): the y-axis points towards the screen,
# therefore the hexagon will be created in the x,z plane, with x-axis pointing to the right
# and the z-axis pointing up
# get the next vertex coordinates by rotating the point (0,0,radius) in the x,z plane
x,z = rotate_phi_degrees_counter_clockwise(phi, (0,radius))
#print (x,z)
vertex.addData3f(x,0,z)
normal.addData3f(0,-1,0) # the normal vector points away from the screen
# add the vertices to a geometry primitives
prim = GeomTrifans(Geom.UHStatic)
for i in range(7):
prim.addVertex(i)
prim.addVertex(1)
prim.closePrimitive()
geom = Geom(vdata)
geom.addPrimitive(prim)
hex_node = GeomNode('')
hex_node.addGeom(geom)
return hex_node, vdata
