It looks like you're new here. If you want to get involved, click one of these buttons!
I would like to know if it is possible to draw paths with round-ended like below right image.
(Outside corner's shape is round)
Before you rely on round path behavior, keep in mind that round path endings in gds cannot be represented in oasis and the behavior at inner path corners is tool dependent as you just experienced. And there is no way to describe the resolution of the roundness even in gds. Thats why in the rare case of having round path in chip layouts, they are usually represented as polygon.
You can achieve this by selecting the path and then: Edit > Selection > Round Corners > Outer Corner Radius = half of your path width, Inner Corner Radius = 0. It will indeed be automatically converted to a polygon.