diff --git a/geometry.scad b/geometry.scad
index f98b95a..f976ac1 100644
--- a/geometry.scad
+++ b/geometry.scad
@@ -1108,7 +1108,7 @@ function circle_2tangents(r, pt1, pt2, pt3, tangents=false, d) =
     assert(r!=undef, "Must specify either r or d.")
     assert( ( is_path(pt1) && len(pt1)==3 && is_undef(pt2) && is_undef(pt3))
             || (is_matrix([pt1,pt2,pt3]) && (len(pt1)==2 || len(pt1)==3) ),
-            "Invalid input points." )
+            str("Invalid input points. pt1=",pt1,", pt2=",pt2,", pt3=",pt3))
     is_undef(pt2)
     ? circle_2tangents(r, pt1[0], pt1[1], pt1[2], tangents=tangents)
     : is_collinear(pt1, pt2, pt3)? undef :
diff --git a/shapes3d.scad b/shapes3d.scad
index f734c79..174cc99 100644
--- a/shapes3d.scad
+++ b/shapes3d.scad
@@ -1388,7 +1388,7 @@ function cylinder(h, r1, r2, center, r, d, d1, d2, anchor, spin=0, orient=UP) =
 // Example: Rounding
 //   cyl(l=40, d=40, rounding=10);
 //
-// Example: Teardrop Bottom Rounding
+// Example(VPD=175;VPR=[90,0,0]): Teardrop Bottom Rounding
 //   cyl(l=40, d=40, rounding=10, teardrop=true);
 //
 // Example: Heterogenous Chamfers and Rounding