Alembic export: normalise the homogeneous component after scaling

The scale matrix must have its homogeneous 'w' (at mat[3][3]) set to the
scale in order to also scale the translations along with it. However, this
also scales the transform matrix's 'w' component, which is not supposed
to happen.

source/blender/alembic/intern/abc_transform.cc

@@ -108,6 +108,7 @@ void AbcTransformWriter::do_write()
 		scale_m4_fl(scale_mat, m_settings.global_scale);
 		scale_mat[3][3] = m_settings.global_scale;  /* also scale translation */
 		mul_m4_m4m4(yup_mat, yup_mat, scale_mat);
+		yup_mat[3][3] /= m_settings.global_scale;  /* normalise the homogeneous component */
 	}
 
 	m_matrix = convert_matrix(yup_mat);