interpCurve3D - find angle of point in world coordsys- How?

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	--Set spline point equal to what point's angle you would like to get back from the script (printed)
	spline_point = undefined 
		--if spline_point is left undefined all angle values for the spline will be printed, which point in the spline each angles corresponds to will also be printed
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--declaring initial variables
knot_positions  = #()
knot_coords_x = #() ; knot_coords_y = #() ; knot_coords_z = #() ; Side_Lengths_A_arr = #() ; Side_Lengths_B_arr = #() ; Side_Lengths_C_arr = #() ; side_length ; Angles_arr =#()
index_1 ; index_2 ; index_3  
spl = selection[1]
vert_count = 6
j = 0
 
for s=1 to (numsplines spl) do( -- for each spline in the scene do
	--vert_count = (numknots spl s)
	for k = 1 to (numknots spl s) do ( --for each knot (each non open point in a spline) do
		format "spline_%_knot_%_pos = % \n" s k (getknotpoint spl s k)
		append knot_positions (getknotpoint spl s k) --append knot position [x,y,z]
 
		append knot_coords_x ( knot_positions[k][1] ) --append x-coordinate
		append knot_coords_y ( knot_positions[k][2] ) --append y-coordinate
		append knot_coords_z ( knot_positions[k][3] ) --append z-coordinate
 
	)
 
format "x coords = % \n y coords =% \n z coords =%  \n" knot_coords_x knot_coords_y knot_coords_z
 
 
for k=1 to (numknots spl s) do( --for each knot (each non open point in a spline) do
	--set initial index values (index_1 is used to get length A value for each triangle)
								--index_2 for length B
								--index_3 for length C
 
	index_1 = k ; index_2 = 1+k ; index_3 = 2+k
 
	--make sure the index values don't become equal to zero or go under zero (this would result in a "no 'get' function for undefined" undefined error
			if( (index_1) > (numknots spl s) )do(
				while index_1 > (numknots spl s) do (
					index_1 = index_1 - (numknots spl s)
					) 
				print "index_1 = index_1 - (numknots spl s)"
				)
 
			if( (index_2) > ( numknots spl s) )do(
				while index_2 > (numknots spl s) do (
					index_2 = index_2 - (numknots spl s)
					)  
				print "index_2 = index_2 - (numknots spl s) "
				)
 
			if( (index_3) > ( numknots spl s) )do(
				while index_3 > (numknots spl s) do (
					index_3 = index_3 - (numknots spl s)
					) 
				print "index_3 = index_3 - (numknots spl s) "
				)
 
			--Calculate triangle side lengths + Append triangle side lengths to corresponding array :
			Side_Length_A = sqrt (   (abs( -1*knot_coords_x[index_1] + knot_coords_x[index_2] ))^2 + (abs ( -1*knot_coords_y[index_1] + knot_coords_y[index_2] ))^2   ) 
				append Side_Lengths_A_arr Side_Length_A
				print side_length_A
 
			Side_Length_B = sqrt (   ( abs( -1*knot_coords_x[index_2] + knot_coords_x[index_3] ))^2 + (abs ( -1*knot_coords_y[index_2] + knot_coords_y[index_3] ))^2   ) 
				append Side_Lengths_B_arr Side_Length_B
				print Side_length_B	
 
			Side_Length_C = sqrt (   ( abs( -1*knot_coords_x[index_3] + knot_coords_x[index_1] ))^2 + (abs ( -1*knot_coords_y[index_3] + knot_coords_y[index_1] ))^2   ) 
				append Side_Lengths_C_arr Side_Length_C
				print Side_Length_C
 
	)
 
for k=(numknots spl s) to ((numknots spl s)*2-1) do( --starting at last knot in spline.. go through all points in the spline and do:
	index_1 = k ; index_2 = 1+k ; index_3 = 2+k
 
			if( (index_1) > (numknots spl s) )do(
				while index_1 > (numknots spl s) do (
					index_1 = index_1 - (numknots spl s)
					) 
				print "index_1 = index_1 - (numknots spl s)"
				)
 
	--k starts at last knot, first calculates length of A then B then C, need to calc. the B angle and append to Angles array 
	--Side_Lengths_A_Arr[index_1] = A
	--				 ..._B_Arr[index_1] = B
	--				 ..._C_Arr[index_1] = C
 
--use cosine rule to calculate angle B (angle B is the angle opposite to side C of each triangle)
	Angle_B = acos (  ( side_lengths_A_arr[index_1]^2 + side_lengths_B_arr[index_1]^2 - side_lengths_C_arr[index_1]^2 )/ (2* side_lengths_A_arr[index_1] * side_lengths_B_arr[index_1]) )
	/*print "Angle_B = acos (  ((side_lengths_A_arr[index_1])^2 + (side_lengths_C_arr[index_1])^2 - (side_lengths_B_arr[index_1])^2 )/ (2* side_lengths_A_arr[index_1] * side_lengths_C_arr[index_1]) ) \n"
	format "									A = %                                                        C = %                                             B = %                                          A = %                                 C = % \n\n" side_lengths_A_arr[index_1] side_lengths_C_arr[index_1] side_lengths_B_arr[index_1] side_lengths_A_arr[index_1] side_lengths_C_arr[index_1] 
	print ("side length A = ") ; print side_lengths_A_arr[index_1]
	print ("side length B = ") ; print side_lengths_B_arr[index_1]
	print ("side length C = ") ; print side_lengths_C_arr[index_1]
	*/
	append Angles_Arr Angle_B
	--format "Angles_arr = % \n" Angles_arr
 
	)
 
if spline_point != undefined then(
i = spline_point - 1 
if i<=0 then (
	while i <=0 do (
		i = i + (numknots spl s)
		format "you requested the angle corresponding to point % in the spline, the angle = % \n" spline_point Angles_arr[i]
		)
	)else(
 
 
			for x=1 to angles_arr.count do ( --go through angles_arr array and print out each angle and what point in the spline's angle it represents
				spline_point = x 
				i = spline_point - 1 
				if i<=0 then (
					while i <=0 do (
						i = i + (numknots spl s)
			)
		)
 
format "vert_num % has angle % \n" i Angles_Arr[i]
 
	)
)
 
 
)--end for s=1 to (numsplines spl) do