add earth sphere utilities

Author: domlysz

__init__.py

@@ -48,6 +48,7 @@
 TERRAIN_RECLASS = True
 BASEMAPS = True
 DROP = True
+EARTH_SPHERE = True
 
 import bpy, os
 
@@ -95,6 +96,8 @@
 	from .operators import view3d_mapviewer
 if DROP:
 	from .operators import object_drop
+if EARTH_SPHERE:
+	from .operators import mesh_earth_sphere
 
 
 import bpy.utils.previews as iconsLib
@@ -144,6 +147,10 @@ def draw(self, context):
 		if DELAUNAY:
 			self.layout.operator("tesselation.delaunay", icon_value=icons_dict["delaunay"].icon_id, text='Delaunay')
 			self.layout.operator("tesselation.voronoi", icon_value=icons_dict["voronoi"].icon_id, text='Voronoi')
+		if EARTH_SPHERE:
+			self.layout.operator("earth.sphere", icon="WORLD", text='lonlat to sphere')
+			#self.layout.operator("earth.curvature", icon="SPHERECURVE", text='Earth curvature correction')
+			self.layout.operator("earth.curvature", icon_value=icons_dict["curve"].icon_id, text='Earth curvature correction')
 
 class VIEW3D_MT_menu_gis_object(bpy.types.Menu):
 	bl_label = "Object"
@@ -238,6 +245,8 @@ def register():
 		nodes_terrain_analysis_builder.register()
 	if TERRAIN_RECLASS:
 		nodes_terrain_analysis_reclassify.register()
+	if EARTH_SPHERE:
+		mesh_earth_sphere.register()
 
 	#menus
 	bpy.types.VIEW3D_MT_editor_menus.append(add_gis_menu)
@@ -306,6 +315,8 @@ def unregister():
 		nodes_terrain_analysis_builder.unregister()
 	if TERRAIN_RECLASS:
 		nodes_terrain_analysis_reclassify.unregister()
+	if EARTH_SPHERE:
+		mesh_earth_sphere.unregister()
 
 if __name__ == "__main__":
 	register()

icons/curve.png

@@ -1 +1 @@
-__all__ = ["add_camera_exif", "add_camera_georef", "io_export_shp", "io_get_srtm", "io_import_georaster", "io_import_osm", "io_import_shp", "io_import_asc", "mesh_delaunay_voronoi", "nodes_terrain_analysis_builder", "nodes_terrain_analysis_reclassify", "view3d_mapviewer", "object_drop"]
+__all__ = ["add_camera_exif", "add_camera_georef", "io_export_shp", "io_get_srtm", "io_import_georaster", "io_import_osm", "io_import_shp", "io_import_asc", "mesh_delaunay_voronoi", "nodes_terrain_analysis_builder", "nodes_terrain_analysis_reclassify", "view3d_mapviewer", "object_drop", "mesh_earth_sphere"]

operators/__init__.py

@@ -0,0 +1,106 @@
+import bpy
+from bpy.types import Operator
+from bpy.props import IntProperty
+
+from math import cos, sin, radians, sqrt
+from mathutils import Vector
+
+import logging
+log = logging.getLogger(__name__)
+
+
+def lonlat2xyz(R, lon, lat):
+	lon, lat = radians(lon), radians(lat)
+	x = R * cos(lat) * cos(lon)
+	y = R * cos(lat) * sin(lon)
+	z = R *sin(lat)
+	return (x, y, z)
+
+
+class OBJECT_OT_earth_sphere(Operator):
+	bl_idname = "earth.sphere"
+	bl_label = "lonlat to sphere"
+	bl_description = "Transform longitude/latitude data to a sphere like earth globe"
+	bl_options = {"REGISTER", "UNDO"}
+
+	radius: IntProperty(name = "Radius", default=100, description="Sphere radius", min=1)
+
+	def execute(self, context):
+		scn = bpy.context.scene
+		obj = bpy.context.view_layer.objects.active
+
+		if not obj:
+			self.report({'INFO'}, "No active object")
+			return {'CANCELLED'}
+
+		if obj.type != 'MESH':
+			self.report({'INFO'}, "Selection isn't a mesh")
+			return {'CANCELLED'}
+
+		w, h, thick = obj.dimensions
+		if w > 360:
+			self.report({'INFO'}, "Longitude exceed 360°")
+			return {'CANCELLED'}
+		if h > 180:
+			self.report({'INFO'}, "Latitude exceed 360°")
+			return {'CANCELLED'}
+
+		mesh = obj.data
+		for vertex in mesh.vertices:
+			lon, lat = vertex.co.x, vertex.co.y
+			vertex.co = lonlat2xyz(self.radius, lon, lat)
+
+		return {'FINISHED'}
+
+EARTH_RADIUS = 6378137 #meters
+def getZDelta(d):
+	'''delta value for adjusting z across earth curvature
+	http://webhelp.infovista.com/Planet/62/Subsystems/Raster/Content/help/analysis/viewshedanalysis.html'''
+	return sqrt(EARTH_RADIUS**2 + d**2) - EARTH_RADIUS
+
+
+class OBJECT_OT_earth_curvature(Operator):
+	bl_idname = "earth.curvature"
+	bl_label = "Earth curvature correction"
+	bl_description = "Apply earth curvature correction for viewsheed analysis"
+	bl_options = {"REGISTER", "UNDO"}
+
+	def execute(self, context):
+		scn = bpy.context.scene
+		obj = bpy.context.view_layer.objects.active
+
+		if not obj:
+			self.report({'INFO'}, "No active object")
+			return {'CANCELLED'}
+
+		if obj.type != 'MESH':
+			self.report({'INFO'}, "Selection isn't a mesh")
+			return {'CANCELLED'}
+
+		mesh = obj.data
+		viewpt = scn.cursor.location
+
+		for vertex in mesh.vertices:
+			d = (viewpt.xy - vertex.co.xy).length
+			vertex.co.z = vertex.co.z - getZDelta(d)
+
+		return {'FINISHED'}
+
+
+classes = [
+	OBJECT_OT_earth_sphere,
+	OBJECT_OT_earth_curvature
+]
+
+def register():
+	for cls in classes:
+		try:
+			bpy.utils.register_class(cls)
+		except ValueError as e:
+			log.warning('{} is already registered, now unregister and retry... '.format(cls))
+			bpy.utils.unregister_class(cls)
+			bpy.utils.register_class(cls)
+
+def unregister():
+	for cls in classes:
+		bpy.utils.unregister_class(cls)