Select_Angles_Python_Script.txt

#written by Eva Herbst and Niccolo Fioritti, 2021

#In Object mode, select object of interest. Paste this script into the Python consolve. Triangles with angles < 20 degrees and > 150 will be selected in Edit mode after script runs. 


import bpy
import math

obj = bpy.context.object

def angle_between_edges(obj,poly,e1,e2):
    common_vert = set(e1).intersection(set(e2))
    if common_vert==set():
        return None
    v0 = list(common_vert)[0]
    v1 = list(set(e1).difference(common_vert))[0]
    v2 = list(set(e2).difference(common_vert))[0]
    vec1 = obj.data.vertices[v1].co -obj.data.vertices[v0].co 
    vec2 = obj.data.vertices[v2].co -obj.data.vertices[v0].co 
    angle = vec1.angle(vec2)
    angle = math.degrees(angle)
    return angle
	
def selectPolygon(angle,polyIndex):
    if(angle is not None):
        if(angle<20 or angle >150):
            obj = bpy.context.active_object
            obj.data.polygons[polyIndex].select = True

            
# 
# 
        


for p_i,poly in enumerate(obj.data.polygons):
    for i,e1 in enumerate(poly.edge_keys):
        for j,e2 in enumerate(poly.edge_keys):
            if i<j:
                angle = angle_between_edges(obj,poly,e1,e2)
                selectPolygon(angle,p_i)
                if angle==None:
                    continue