Tried and rejected the Insomniac fix.

It resulted in a large loss of precision in some cases.

Should have another look at what Imath is doing instead.

src/euler.rs

@@ -353,7 +353,6 @@ macro_rules! impl_mat3_to_euler {
  let sy = math::sqrt(
  self.col(i)[j] * self.col(i)[j] + self.col(i)[k] * self.col(i)[k],
  );
- // TODO: https://d3cw3dd2w32x2b.cloudfront.net/wp-content/uploads/2012/07/euler-angles1.pdf
  if (sy > 16.0 * $scalar::EPSILON) {
  ea.x = math::atan2(self.col(i)[j], self.col(i)[k]);
  ea.y = math::atan2(sy, self.col(i)[i]);
@@ -366,7 +365,6 @@ macro_rules! impl_mat3_to_euler {
  let cy = math::sqrt(
  self.col(i)[i] * self.col(i)[i] + self.col(j)[i] * self.col(j)[i],
  );
- // TODO: https://d3cw3dd2w32x2b.cloudfront.net/wp-content/uploads/2012/07/euler-angles1.pdf
  if (cy > 16.0 * $scalar::EPSILON) {
  ea.x = math::atan2(self.col(k)[j], self.col(k)[k]);
  ea.y = math::atan2(-self.col(k)[i], cy);