Create vertex.py

Extract polygon vertex in dem coordinate system (X, Y,Z)

app/models/vertex.py

@@ -0,0 +1,40 @@
+from osgeo import ogr
+import gdal
+import struct
+import json 
+
+def convertJson(jsdata):
+  return json.dumps(jsdata)
+
+def rings(raster, geojson):
+  
+  src=gdal.Open(raster)
+  gtx=src.GetGeoTransform() 
+  rbu=src.GetRasterBand(1)
+  gdal.UseExceptions()
+
+  geo=convertJson(geojson)
+
+  geojsom= ogr.Open(geo)
+
+  layer1 = geojsom.GetLayer(0)
+  
+  vertices = []
+
+  for feat in layer1:
+    geom = feat.GetGeometryRef()
+    ring = geom.GetGeometryRef(0)
+    points = ring.GetPointCount()
+
+  for p in range(points):
+    lon, lat, z = ring.GetPoint(p)
+    px = int((lon - gtx[0]) / gtx[1]) #x pixel
+    py = int((lat - gtx[3]) / gtx[5]) #y pixel
+    try:
+        structval=rbu.ReadRaster(px,py,1,1,buf_type=gdal.GDT_Float32) #Assumes 32 bit int- 'float'
+        intval = struct.unpack('f' , structval) #assume float
+        val=intval[0]
+        vertices.append((px, py, val))
+    except:
+        val=-9999 #or some value to indicate a fail
+  return vertices