Manual Support
Add: Only after click the "Add" button then can you add the support to the model.
Delete: Click the "Delete" button first, and then click the support on the model and click
"Delete" button to remove the support.
Edit: The support can be edited after clicking the "Edit" button. Click the support,
it will become red. Its shape can be changed through editing the top, mid and
bottom parameters. Besides, left click the model, hold on and move the mouse
can change the position of the support.
contour line, it can be used as reference line
when you are adding support
When the mouse moves on the model, the green short
line can be clicked to add support; the red short line
means it can not be clicked to add support