I'm trying to convert a ply to a polyhedron stored in postgis. In this example I have a cube from 0,0,0 to 1,1,1 the script below brings in a geometry to postgis, it is there, no problem, however I go to calculate the volume and it gives the following error:
query:
SELECT ST_Volume(st_geomfromtext) FROM public.test3
error:
ERROR: PolyhedralSurface is invalid : inconsistent orientation of PolyhedralSurface detected at edge 1 (4-3) of polygon 11 : POLYHEDRALSURFACE(((1/1 1/1 0/1,1/1 0/1 0/1,0/1 0/1 0/1,1/1 1/1 0/1)),((1/1 0/1 0/1,1/1 0/1 1/1,0/1 0/1 0/1,1/1 0/1 0/1)),((1/1 0/1 0/1,1
SQL state: XX000
The object is a cube 0,0,0 to 1,1,1, here it is as an array of vertices and triangles.
vertices:
array([[ 1., 1., -0.],
[ 1., 0., -0.],
[ 0., 0., -0.],
[ 0., 1., -0.],
[ 1., 1., 1.],
[ 0., 1., 1.],
[ 0., 0., 1.],
[ 1., 0., 1.],
[ 1., 1., -0.],
[ 1., 1., 1.],
[ 1., 0., 1.],
[ 1., 0., -0.],
[ 1., 0., -0.],
[ 1., 0., 1.],
[ 0., 0., 1.],
[ 0., 0., -0.],
[ 0., 0., -0.],
[ 0., 0., 1.],
[ 0., 1., 1.],
[ 0., 1., -0.],
[ 1., 1., 1.],
[ 1., 1., -0.],
[ 0., 1., -0.],
[ 0., 1., 1.]])
The triangles are defined as:
array([[ 0, 1, 2],
[ 0, 2, 3],
[ 4, 5, 6],
[ 4, 6, 7],
[ 8, 9, 10],
[ 8, 10, 11],
[12, 13, 14],
[12, 14, 15],
[16, 17, 18],
[16, 18, 19],
[20, 21, 22],
[20, 22, 23]], dtype=int32)
I put together this conversion script to take a ply and add it to postgis:
import numpy as np
from open3d import *
import psycopg2
import dbconfig
def connect_db():
global connection
connection = psycopg2.connect(host=dbconfig.DATABASE_CONFIG['host'],
user=dbconfig.DATABASE_CONFIG['user'],
password=dbconfig.DATABASE_CONFIG['password'],
dbname=dbconfig.DATABASE_CONFIG['dbname'])
return connection
# mesh = read_triangle_mesh('C:/Users/garyn/PycharmProjects/pointcloudprocessor/tmp/contexts/99.526/396.ply')
mesh = read_triangle_mesh('C:/Users/garyn/PycharmProjects/pointcloudprocessor/tmp/contexts/cube3.ply')
verts = mesh.vertices
verts = np.asarray(verts)
tri = mesh.triangles
tri = np.asarray(tri)
data = ''
header = ("'POLYHEDRALSURFACE(")
for i in range(len(tri)):
# for i in range(0,2):
x1 = (tri[i][0]) # 3
y1 = (tri[i][1]) # 44
z1 = (tri[i][2]) # 1
x_coords1 = verts[x1][0]
y_coords1 = verts[y1][0]
z_coords1 = verts[z1][0]
x_coords2 = verts[x1][1]
y_coords2 = verts[y1][1]
z_coords2 = verts[z1][1]
x_coords3 = verts[x1][2]
y_coords3 = verts[y1][2]
z_coords3 = verts[z1][2]
data += "((%s %s %s, %s %s %s, %s %s %s, %s %s %s))," % \
(x_coords1, y_coords1, z_coords1, \
x_coords2, y_coords2, z_coords2, \
x_coords3, y_coords3, z_coords3, \
x_coords1, y_coords1, z_coords1)
data = data[:-1]
projection = ")',32635)"
create_stmt = "CREATE TABLE test3 AS "
select_stmt = "SELECT ST_GeomFromText("
polyhedron = header + data + projection
query = create_stmt + select_stmt + polyhedron
conn = connect_db()
cur = conn.cursor()
cur.execute(query)
conn.commit()
cur.close()
conn.close()
Which results in:
CREATE TABLE test3 AS
SELECT ST_GeomFromText('POLYHEDRALSURFACE(((1.0 1.0 0.0, 1.0 0.0 0.0, -0.0 -0.0 -0.0, 1.0 1.0 0.0)),((1.0 0.0 0.0, 1.0 0.0 1.0, -0.0 -0.0 -0.0, 1.0 0.0 0.0)),((1.0 0.0 0.0, 1.0 1.0 0.0, 1.0 1.0 1.0, 1.0 0.0 0.0)),((1.0 0.0 1.0, 1.0 0.0 0.0, 1.0 1.0 1.0, 1.0 0.0 1.0)),((1.0 1.0 1.0, 1.0 1.0 0.0, -0.0 1.0 1.0, 1.0 1.0 1.0)),((1.0 1.0 1.0, 1.0 0.0 0.0, -0.0 1.0 -0.0, 1.0 1.0 1.0)),((1.0 1.0 0.0, 0.0 0.0 0.0, -0.0 1.0 1.0, 1.0 1.0 0.0)),((1.0 0.0 0.0, 0.0 0.0 0.0, -0.0 1.0 -0.0, 1.0 0.0 0.0)),((0.0 0.0 0.0, 0.0 0.0 1.0, -0.0 1.0 1.0, 0.0 0.0 0.0)),((0.0 0.0 0.0, 0.0 1.0 1.0, -0.0 1.0 -0.0, 0.0 0.0 0.0)),((1.0 1.0 0.0, 1.0 1.0 1.0, 1.0 -0.0 -0.0, 1.0 1.0 0.0)),((1.0 0.0 0.0, 1.0 1.0 1.0, 1.0 -0.0 1.0, 1.0 0.0 0.0)))',32635)
It looks ok to me and postgis accepts it as a polyhedral surface, but how do I make sure the cube is constructed correctly? P.S. and postgis 3D viewers out there, I'm doing this blind.
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